29 CFR 1910.217(g)

e-CFR Data is current as of May 2, 2012
Title 29: Labor
PART 1910—OCCUPATIONAL SAFETY AND HEALTH STANDARDS
Subpart O—Machinery and Machine Guarding
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§ 1910.217 Mechanical power presses.
(a) General requirements. (1)–(3) [Reserved]
(4) Reconstruction and modification. It shall be the responsibility of any person reconstructing, or modifying a
mechanical power press to do so in accordance with paragraph (b) of this section.
(5) Excluded machines. Press brakes, hydraulic and pneumatic power presses, bulldozers, hot bending and hot metal
presses, forging presses and hammers, riveting machines and similar types of fastener applicators are excluded from
the requirements of this section.
(b) Mechanical power press guarding and construction, general —(1) Hazards to personnel associated with broken or
falling machine components. Machine components shall be designed, secured, or covered to minimize hazards
caused by breakage, or loosening and falling or release of mechanical energy (i.e. broken springs).
(2) Brakes. Friction brakes provided for stopping or holding a slide movement shall be inherently self-engaging by
requiring power or force from an external source to cause disengagement. Brake capacity shall be sufficient to stop
the motion of the slide quickly and capable of holding the slide and its attachments at any point in its travel.
(3) Machines using full revolution positive clutches. (i) Machines using full revolution clutches shall incorporate a
single-stroke mechanism.
(ii) If the single-stroke mechanism is dependent upon spring action, the spring(s) shall be of the compression type,
operating on a rod or guided within a hole or tube, and designed to prevent interleaving of the spring coils in event of
breakage.
(4) Foot pedals (treadle). (i) The pedal mechanism shall be protected to prevent unintended operation from falling or
moving objects or by accidental stepping onto the pedal.
(ii) A pad with a nonslip contact area shall be firmly attached to the pedal.
(iii) The pedal return spring(s) shall be of the compression type, operating on a rod or guided within a hole or tube, or
designed to prevent interleaving of spring coils in event of breakage.
(iv) If pedal counterweights are provided, the path of the travel of the weight shall be enclosed.
(5) Hand operated levers. (i) Hand-lever-operated power presses shall be equipped with a spring latch on the
operating lever to prevent premature or accidental tripping.
(ii) The operating levers on hand-tripped presses having more than one operating station shall be interlocked to
prevent the tripping of the press except by the “concurrent” use of all levers.
(6) Two-hand trip. (i) A two-hand trip shall have the individual operator's hand controls protected against unintentional
operation and have the individual operator's hand controls arranged by design and construction and/or separation to

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require the use of both hands to trip the press and use a control arrangement requiring concurrent operation of the
individual operator's hand controls.
(ii) Two-hand trip systems on full revolution clutch machines shall incorporate an antirepeat feature.
(iii) If two-hand trip systems are used on multiple operator presses, each operator shall have a separate set of
controls.
(7) Machines using part revolution clutches. (i) The clutch shall release and the brake shall be applied when the
external clutch engaging means is removed, deactivated, or deenergized.
(ii) A red color stop control shall be provided with the clutch/brake control system. Momentary operation of the stop
control shall immediately deactivate the clutch and apply the brake. The stop control shall override any other control,
and reactuation of the clutch shall require use of the operating (tripping) means which has been selected.
(iii) A means of selecting Off, “Inch,” Single Stroke, and Continuous (when the continuous function is furnished) shall
be supplied with the clutch/brake control to select type of operation of the press. Fixing of selection shall be by means
capable of supervision by the employer.
(iv) The “Inch” operating means shall be designed to prevent exposure of the workers hands within the point of
operation by:
( a ) Requiring the concurrent use of both hands to actuate the clutch, or
( b ) Being a single control protected against accidental actuation and so located that the worker cannot reach into the
point of operation while operating the single control.
(v) Two-hand controls for single stroke shall conform to the following requirements:
( a ) Each hand control shall be protected against unintended operation and arranged by design, construction, and/or
separation so that the concurrent use of both hands is required to trip the press.
( b ) The control system shall be designed to permit an adjustment which will require concurrent pressure from both
hands during the die closing portion of the stroke.
( c ) The control system shall incorporate an antirepeat feature.
( d ) The control systems shall be designed to require release of all operators' hand controls before an interrupted
stroke can be resumed. This requirement pertains only to those single-stroke, two-hand controls manufactured and
installed on or after August 31, 1971.
(vi) [Reserved]
(vii) Controls for more than one operating station shall be designed to be activated and deactivated in complete sets
of two operator's hand controls per operating station by means capable of being supervised by the employer. The
clutch/brake control system shall be designed and constructed to prevent actuation of the clutch if all operating
stations are bypassed.
(viii) Those clutch/brake control systems which contain both single and continuous functions shall be designed so that
completion of continuous circuits may be supervised by the employer. The initiation of continuous run shall require a
prior action or decision by the operator in addition to the selection of Continuous on the stroking selector, before
actuation of the operating means will result in continuous stroking.
(ix) If foot control is provided, the selection method between hand and foot control shall be separate from the stroking
selector and shall be designed so that the selection may be supervised by the employer.

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(x) Foot operated tripping controls, if used, shall be protected so as to prevent operation from falling or moving
objects, or from unintended operation by accidental stepping onto the foot control.
(xi) The control of air-clutch machines shall be designed to prevent a significant increase in the normal stopping time
due to a failure within the operating value mechanism, and to inhibit further operation if such failure does occur. This
requirement shall apply only to those clutch/brake air-valve controls manufactured and installed on or after August 31,
1971, but shall not apply to machines intended only for continuous, automatic feeding applications.
(xii) The clutch/brake control shall incorporate an automatic means to prevent initiation or continued activation of the
Single Stroke or Continuous functions unless the press drive motor is energized and in the forward direction.
(xiii) The clutch/brake control shall automatically deactivate in event of failure of the power or pressure supply for the
clutch engaging means. Reactivation of the clutch shall require restoration of normal supply and the use of the
tripping mechanism(s).
(xiv) The clutch/brake control shall automatically deactivate in event of failure of the counterbalance(s) air supply.
Reactivation of the clutch shall require restoration of normal air supply and use of the tripping mechanism(s).
(xv) Selection of bar operation shall be by means capable of being supervised by the employer. A separate
pushbutton shall be employed to activate the clutch, and the clutch shall be activated only if the driver motor is
deenergized.
(8) Electrical. (i) A main power disconnect switch capable of being locked only in the Off position shall be provided
with every power press control system.
(ii) The motor start button shall be protected against accidental operation.
(iii) All mechanical power press controls shall incorporate a type of drive motor starter that will disconnect the drive
motor from the power source in event of control voltage or power source failure, and require operation of the motor
start button to restart the motor when voltage conditions are restored to normal.
(iv) All a.c. control circuits and solenoid value coils shall be powered by not more than a nominal 120-volt a.c. supply
obtained from a transformer with an isolated secondary. Higher voltages that may be necessary for operation of
machine or control mechanisms shall be isolated from any control mechanism handled by the operator, but motor
starters with integral Start-Stop buttons may utilize line voltage control. All d.c. control circuits shall be powered by not
more than a nominal 240-volt d.c. supply isolated from any higher voltages.
(v) All clutch/brake control electrical circuits shall be protected against the possibility of an accidental ground in the
control circuit causing false operation of the press.
(vi) Electrical clutch/brake control circuits shall incorporate features to minimize the possibility of an unintended stroke
in the event of the failure of a control component to function properly, including relays, limit switches, and static output
circuits.
(9) Slide counterbalance systems. (i) Spring counterbalance systems when used shall incorporate means to retain
system parts in event of breakage.
(ii) Spring counterbalances when used shall have the capability to hold the slide and its attachments at midstroke,
without brake applied.
(iii) Air counterbalance cylinders shall incorporate means to retain the piston and rod in case of breakage or
loosening.
(iv) Air counterbalance cylinders shall have adequate capability to hold the slide and its attachments at any point in
stroke, without brake applied.

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(v) Air counterbalance cylinders shall incorporate means to prevent failure of capability (sudden loss of pressure) in
event of air supply failure.
(10) Air controlling equipment. Air controlling equipment shall be protected against foreign material and water
entering the pneumatic system of the press. A means of air lubrication shall be provided when needed.
(11) Hydraulic equipment. The maximum anticipated working pressures in any hydraulic system on a mechanical
power press shall not exceed the safe working pressure rating of any component used in that system.
(12) Pressure vessels. All pressure vessels used in conjunction with power presses shall conform to the American
Society of Mechanical Engineers Code for Pressure Vessels, 1968 Edition, which is incorporated by reference as
specified in §1910.6.
(13) Control reliability. When required by paragraph (c)(5) of this section, the control system shall be constructed so
that a failure within the system does not prevent the normal stopping action from being applied to the press when
required, but does prevent initiation of a successive stroke until the failure is corrected. The failure shall be detectable
by a simple test, or indicated by the control system. This requirement does not apply to those elements of the control
system which have no effect on the protection against point of operation injuries.
(14) Brake system monitoring. When required by paragraph (c)(5) of this section, the brake monitor shall meet the
following requirements:
(i) Be so constructed as to automatically prevent the activation of a successive stroke if the stopping time or braking
distance deteriorates to a point where the safety distance being utilized does not meet the requirements set forth in
paragraph (c)(3)(iii)( e ) or (c)(3)(vii)( c ) of this section. The brake monitor used with the Type B gate or movable
barrier device shall be installed in a manner to detect slide top-stop overrun beyond the normal limit reasonably
established by the employer.
(ii) Be installed on a press such that it indicates when the performance of the braking system has deteriorated to the
extent described in paragraph (b)(14)(i) of this section; and
(iii) Be constructed and installed in a manner to monitor brake system performance on each stroke.
(c) Safeguarding the point of operation —(1) General requirements. (i) It shall be the responsibility of the employer to
provide and insure the usage of “point of operation guards” or properly applied and adjusted point of operation
devices on every operation performed on a mechanical power press. See Table O–10.
(ii) The requirement of paragraph (c)(1)(i) of this section shall not apply when the point of operation opening is onefourth inch or less. See Table O–10.
(2) Point of operation guards. (i) Every point of operation guard shall meet the following design, construction,
application, and adjustment requirements:
( a ) It shall prevent entry of hands or fingers into the point of operation by reaching through, over, under or around
the guard;
( b ) It shall conform to the maximum permissible openings of Table O–10;
( c ) It shall, in itself, create no pinch point between the guard and moving machine parts;
( d ) It shall utilize fasteners not readily removable by operator, so as to minimize the possibility of misuse or removal
of essential parts;
( e ) It shall facilitate its inspection, and
( f ) It shall offer maximum visibility of the point of operation consistent with the other requirements.

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(ii) A die enclosure guard shall be attached to the die shoe or stripper in a fixed position.
(iii) A fixed barrier guard shall be attached securely to the frame of the press or to the bolster plate.
(iv) An interlocked press barrier guard shall be attached to the press frame or bolster and shall be interlocked with the
press clutch control so that the clutch cannot be activated unless the guard itself, or the hinged or movable sections
of the guard are in position to conform to the requirements of Table O–10.
(v) The hinged or movable sections of an interlocked press barrier guard shall not be used for manual feeding. The
guard shall prevent opening of the interlocked section and reaching into the point of operation prior to die closure or
prior to the cessation of slide motion. See paragraph (c)(3)(ii) of this section regarding manual feeding through
interlocked press barrier devices.
(vi) The adjustable barrier guard shall be securely attached to the press bed, bolster plate, or die shoe, and shall be
adjusted and operated in conformity with Table O–10 and the requirements of this subparagraph. Adjustments shall
be made only by authorized personnel whose qualifications include a knowledge of the provisions of Table O–10 and
this subparagraph.
(vii) A point of operation enclosure which does not meet the requirements of this subparagraph and Table O–10 shall
be used only in conjunction with point of operation devices.
(3) Point of operation devices. (i) Point of operation devices shall protect the operator by:
( a ) Preventing and/or stopping normal stroking of the press if the operator's hands are inadvertently placed in the
point of operation; or
( b ) Preventing the operator from inadvertently reaching into the point of operation, or withdrawing his hands if they
are inadvertently located in the point of operation, as the dies close; or
( c ) Preventing the operator from inadvertently reaching into the point of operation at all times; or
( d ) [Reserved]
( e ) Requiring application of both of the operator's hands to machine operating controls and locating such controls at
such a safety distance from the point of operation that the slide completes the downward travel or stops before the
operator can reach into the point of operation with his hands; or
( f ) Enclosing the point of operation before a press stroke can be initiated, and maintaining this closed condition until
the motion of the slide had ceased; or
( g ) Enclosing the point of operation before a press stroke can be initiated, so as to prevent an operator from
reaching into the point of operation prior to die closure or prior to cessation of slide motion during the downward
stroke.
(ii) A gate or movable barrier device shall protect the operator as follows:
( a ) A Type A gate or movable barrier device shall protect the operator in the manner specified in paragraph (c)(3)(i)(
f ) of this section, and
( b ) A Type B gate or movable barrier device shall protect the operator in the manner specified in paragraph (c)(3)(i)(
g ) of this section.
(iii) A presence sensing point of operation device shall protect the operator as provided in paragraph (c)(3)(i)( a ) of
this section, and shall be interlocked into the control circuit to prevent or stop slide motion if the operator's hand or
other part of his body is within the sensing field of the device during the downstroke of the press slide.

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( a ) The device may not be used on machines using full revolution clutches.
( b ) The device may not be used as a tripping means to initiate slide motion, except when used in total conformance
with paragraph (h) of this section.
( c ) The device shall be constructed so that a failure within the system does not prevent the normal stopping action
from being applied to the press when required, but does prevent the initiation of a successive stroke until the failure is
corrected. The failure shall be indicated by the system.
( d ) Muting (bypassing of the protective function) of such device, during the upstroke of the press slide, is permitted
for the purpose of parts ejection, circuit checking, and feeding.
( e ) The safety distance (Ds) from the sensing field to the point of operation shall be greater than the distance
determined by the following formula:
Ds= 63 inches/second × Ts

where:
Ds= minimum safety distance (inches); 63 inches/second=hand speed constant;
and
Ts= stopping time of the press measured at approximately 90° position of crankshaft rotation (seconds).
( f ) Guards shall be used to protect all areas of entry to the point of operation not protected by the presence sensing
device.
(iv) The pull-out device shall protect the operator as specified in paragraph (c)(3)(i)( b ) of this section, and shall
include attachments for each of the operator's hands.
( a ) Attachments shall be connected to and operated only by the press slide or upper die.
( b ) Attachments shall be adjusted to prevent the operator from reaching into the point of operation or to withdraw the
operator's hands from the point of operation before the dies close.
( c ) A separate pull-out device shall be provided for each operator if more than one operator is used on a press.
( d ) Each pull-out device in use shall be visually inspected and checked for proper adjustment at the start of each
operator shift, following a new die set-up, and when operators are changed. Necessary maintenance or repair or both
shall be performed and completed before the press is operated. Records of inspections and maintenance shall be
kept in accordance with paragraph (e) of this section.
(v) The sweep device may not be used for point of operation safeguarding.
(vi) A holdout or a restraint device shall protect the operator as specified in paragraph (c)(3)(i)( c ) of this section and
shall include attachments for each of the operator's hands. Such attachments shall be securely anchored and
adjusted in such a way that the operator is restrained from reaching into the point of operation. A separate set of
restraints shall be provided for each operator if more than one operator is required on a press.
(vii) The two hand control device shall protect the operator as specified in paragraph (c)(3)(i)( e ) of this section.
( a ) When used in press operations requiring more than one operator, separate two hand controls shall be provided
for each operator, and shall be designed to require concurrent application of all operators' controls to activate the
slide. The removal of a hand from any control button shall cause the slide to stop.

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( b ) Each two hand control shall meet the construction requirements of paragraph (b)(7)(v) of this section.
( c ) The safety distance (Ds) between each two hand control device and the point of operation shall be greater than
the distance determined by the following formula:
Ds= 63 inches/second × Ts;

where:
Ds= minimum safety distance (inches); 63 inches/second=hand speed constant;
and
Ts= stopping time of the press measured at approximately 90° position of crankshaft rotation (seconds).
( d ) Two hand controls shall be fixed in position so that only a supervisor or safety engineer is capable of relocating
the controls.
(viii) The two hand trip device shall protect the operator as specified in paragraph (c)(3)(i)( e ) of this section.
( a ) When used in press operations requiring more than one operator, separate two hand trips shall be provided for
each operator, and shall be designed to require concurrent application of all operators' to activate the slide.
( b ) Each two hand trip shall meet the construction requirements of paragraph (b)(6) of this section.
( c ) The safety distance (Dm) between the two hand trip and the point of operation shall be greater than the distance
determined by the following formula:
Dm= 63 inches/second×Tm;

where:
Dm= minimum safety distance (inches); 63 inches/second=hand speed constant;
and
Tm= the maximum time the press takes for the die closure after it has been tripped (seconds). For full
revolution clutch presses with only one engaging point Tmis equal to the time necessary for one and onehalf revolutions of the crankshaft. For full revolution clutch presses with more than one engaging point,
Tmshall be calculated as follows:
Tm= [1/2+ (1 ÷ Number of engaging points per revolution)] × time necessary to complete one revolution of
the crankshaft (seconds).
( d ) Two hand trips shall be fixed in position so that only a supervisor or safety engineer is capable of relocating the
controls.
(4) Hand feeding tools. Hand feeding tools are intended for placing and removing materials in and from the press.
Hand feeding tools are not a point of operation guard or protection device and shall not be used in lieu of the “guards”
or devices required in this section.
(5) Additional requirements for safe-guarding. Where the operator feeds or removes parts by placing one or both
hands in the point of operation, and a two hand control, presence sensing device, Type B gate or movable barrier (on
a part revolution clutch) is used for safeguarding:

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(i) The employer shall use a control system and a brake monitor which comply with paragraphs (b) (13) and (14) of
this section;
(ii) The exception in paragraph (b)(7)(v)( d ) of this section for two hand controls manufactured and installed before
August 31, 1971 is not applicable under this paragraph (c)(5);
(iii) The control of air clutch machines shall be designed to prevent a significant increase in the normal stopping time
due to a failure within the operating valve mechanism, and to inhibit further operation if such failure does occur,
where a part revolution clutch is employed. The exception in paragraph (b)(7)(xi) of this section for controls
manufactured and installed before August 31, 1971, is not applicable under this paragraph (c)(5).
(d) Design, construction, setting and feeding of dies —(1) General requirements. The employer shall: (i) Use dies and
operating methods designed to control or eliminate hazards to operating personnel, and (ii) furnish and enforce the
use of hand tools for freeing and removing stuck work or scrap pieces from the die, so that no employee need reach
into the point of operation for such purposes.
(2) [Reserved]
(3) Scrap handling. The employer shall provide means for handling scrap from roll feed or random length stock
operations. Scrap cutters used in conjunction with scrap handling systems shall be safeguarded in accordance with
paragraph (c) of this section and with §1910.219.
(4) Guide post hazard. The hazard created by a guide post (when it is located in the immediate vicinity of the
operator) when separated from its bushing by more than one-fourth inch shall be considered as a point of operation
hazard and be protected in accordance with paragraph (c) of this section.
(5) Unitized tooling. If unitized tooling is used, the opening between the top of the punch holder and the face of the
slide, or striking pad, shall be safeguarded in accordance with the requirements of paragraph (c) of this section.
(6) Tonnage, stroke, and weight designation. All dies shall be:
(i) Stamped with the tonnage and stroke requirements, or have these characteristics recorded if these records are
readily available to the die setter;
(ii) Stamped to indicate upper die weight when necessary for air counterbalance pressure adjustment; and
(iii) Stamped to indicate complete die weight when handling equipment may become overloaded.
(7) Die fastening. Provision shall be made in both the upper and lower shoes for securely mounting the die to the
bolster and slide. Where clamp caps or setscrews are used in conjunction with punch stems, additional means of
securing the upper shoe to the slide shall be used.
(8) Die handling. Handling equipment attach points shall be provided on all dies requiring mechanical handling.
(9) Diesetting. (i) The employer shall establish a diesetting procedure that will insure compliance with paragraph (c) of
this section.
(ii) The employer shall provide spring loaded turnover bars, for presses designed to accept such turnover bars.
(iii) The employer shall provide die stops or other means to prevent losing control of the die while setting or removing
dies in presses which are inclined.
(iv) The employer shall provide and enforce the use of safety blocks for use whenever dies are being adjusted or
repaired in the press.

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(v) The employer shall provide brushes, swabs, lubricating rolls, and automatic or manual pressure guns so that
operators and diesetters shall not be required to reach into the point of operation or other hazard areas to lubricate
material, punches or dies.
(e) Inspection, maintenance, and modification of presses —(1) Inspection and maintenance records. (i) It shall be the
responsibility of the employer to establish and follow a program of periodic and regular inspections of his power
presses to ensure that all their parts, auxiliary equipment, and safeguards are in a safe operating condition and
adjustment. The employer shall maintain a certification record of inspections which includes the date of inspection,
the signature of the person who performed the inspection and the serial number, or other identifier, of the power
press that was inspected.
(ii) Each press shall be inspected and tested no less than weekly to determine the condition of the clutch/brake
mechanism, antirepeat feature and single stroke mechanism. Necessary maintenance or repair or both shall be
performed and completed before the press is operated. These requirements do not apply to those presses which
comply with paragraphs (b) (13) and (14) of this section. The employer shall maintain a certification record of
inspections, tests and maintenance work which includes the date of the inspection, test or maintenance; the signature
of the person who performed the inspection, test, or maintenance; and the serial number or other identifier of the
press that was inspected, tested or maintained.
(2) Modification. It shall be the responsibility of any person modifying a power press to furnish instructions with the
modification to establish new or changed guidelines for use and care of the power press so modified.
(3) Training of maintenance personnel. It shall be the responsibility of the employer to insure the original and
continuing competence of personnel caring for, inspecting, and maintaining power presses.
(f) Operation of power presses —(1) [Reserved]
(2) Instruction to operators. The employer shall train and instruct the operator in the safe method of work before
starting work on any operation covered by this section. The employer shall insure by adequate supervision that
correct operating procedures are being followed.
(3) Work area. The employer shall provide clearance between machines so that movement of one operator will not
interfere with the work of another. Ample room for cleaning machines, handling material, work pieces, and scrap shall
also be provided. All surrounding floors shall be kept in good condition and free from obstructions, grease, oil, and
water.
(4) Overloading. The employer shall operate his presses within the tonnage and attachment weight ratings specified
by the manufacturer.

View or download PDF

Explanation of above diagram:
This diagram shows the accepted safe openings between the bottom edge of a guard and feed table at
various distances from the danger line (point of operation).

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The clearance line marks the distance required to prevent contact between guard and moving parts.
The minimum guarding line is the distance between the infeed side of the guard and the danger line
which is one-half inch from the danger line.
The various openings are such that for average size hands an operator's fingers won't reach the point of
operation.
After installation of point of operation guards and before a job is released for operation a check should be
made to verify that the guard will prevent the operator's hands from reaching the point of operation.
Table O–10
[In inches]

Distance of opening from point of operation hazard

Maximum width of opening

1/2 to 1 1/2

1/4

1 1/2 to 2 1/2

3/8

2 1/2 to 3 1/2

1/2

3 1/2 to 5 1/2

5/8

5 1/2 to 6 1/2

3/4

6 1/2 to 7 1/2

7/8

7 1/2 to 12 1/2

1 1/4

12 1/2 to 15 1/2

1 1/2

15 1/2 to 17 1/2

1 7/8

17 1/2 to 31 1/2

2 1/8

This table shows the distances that guards shall be positioned from the danger line in accordance with
the required openings.
(g) Reports of injuries to employees operating mechanical power presses. (1) The employer shall report, within 30
days of the occurrence, all point-of-operation injuries to operators or other employees to either (1) the Director of the
Directorate of Standards and Guidance at OSHA, U.S. Department of Labor, Washington, DC 20210 (
http://www.osha.gov/pls/oshaweb/mechanical.html ), or
(2) The State agency administering a plan approved by the Assistant Secretary of Labor for Occupational Safety and
Health.
(h) Presence sensing device initiation (PSDI) — (1) General. (i) The requirements of paragraph (h) shall apply to all
part revolution mechanical power presses used in the PSDI mode of operation.
(ii) The relevant requirements of paragraphs (a) through (g) of this section also shall apply to all presses used in the
PSDI mode of operation, whether or not cross referenced in this paragraph (h). Such cross-referencing of specific
requirements from paragraphs (a) through (g) of this section is intended only to enhance convenience and

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understanding in relating to the new provisions to the existing standard, and is not to be construed as limiting the
applicability of other provisions in paragraphs (a) through (g) of this section.
(iii) Full revolution mechanical power presses shall not be used in the PSDI mode of operation.
(iv) Mechanical power presses with a configuration which would allow a person to enter, pass through, and become
clear of the sensing field into the hazardous portion of the press shall not be used in the PSDI mode of operation.
(v) The PSDI mode of operation shall be used only for normal production operations. Die-setting and maintenance
procedures shall comply with paragraphs (a) through (g) of this section, and shall not be done in the PSDI mode.
(2) Brake and clutch requirements. (i) Presses with flexible steel band brakes or with mechanical linkage actuated
brakes or clutches shall not be used in the PSDI mode.
(ii) Brake systems on presses used in the PSDI mode shall have sufficient torque so that each average value of
stopping times (Ts) for stops initiated at approximately 45 degrees, 60 degrees, and 90 degrees, respectively, of
crankshaft angular position, shall not be more than 125 percent of the average value of the stopping time at the top
crankshaft position. Compliance with this requirement shall be determined by using the heaviest upper die to be used
on the press, and operating at the fastest press speed if there is speed selection.
(iii) Where brake engagement and clutch release is effected by spring action, such spring(s) shall operate in
compression on a rod or within a hole or tube, and shall be of non-interleaving design.
(3) Pneumatic systems. (i) Air valve and air pressure supply/control.
(A) The requirements of paragraphs (b)(7)(xiii), (b)(7)(xiv), (b)(10), (b)(12) and (c)(5)(iii) of this section apply to the
pneumatic systems of machines used in the PSDI mode.
(B) The air supply for pneumatic clutch/brake control valves shall incorporate a filter, an air regulator, and, when
necessary for proper operation, a lubricator.
(C) The air pressure supply for clutch/brake valves on machines used in the PSDI mode shall be regulated to
pressures less than or equal to the air pressure used when making the stop time measurements required by
paragraph (h)(2)(ii) of this section.
(ii) Air counterbalance systems.
(A) Where presses that have slide counterbalance systems are used in the PSDI mode, the counterbalance system
shall also meet the requirements of paragraph (b)(9) of this section.
(B) Counterbalances shall be adjusted in accordance with the press manufacturer's recommendations to assure
correct counterbalancing of the slide attachment (upper die) weight for all operations performed on presses used in
the PSDI mode. The adjustments shall be made before performing the stopping time measurements required by
paragraphs (h)(2)(ii), (h)(5)(iii), and (h)(9)(v) of this section.
(4) Flywheels and bearings. Presses whose designs incorporate flywheels running on journals on the crankshaft or
back shaft, or bull gears running on journals mounted on the crankshaft, shall be inspected, lubricated, and
maintained as provided in paragraph (h)(10) of this section to reduce the possibility of unintended and uncontrolled
press strokes caused by bearing seizure.
(5) Brake monitoring. (i) Presses operated in the PSDI mode shall be equipped with a brake monitor that meets the
requirements of paragraphs (b)(13) and (b)(14) of this section. In addition, the brake monitor shall be adjusted during
installation certification to prevent successive stroking of the press if increases in stopping time cause an increase in
the safety distance above that required by paragraph (h)(9)(v) of this section.

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(ii) Once the PSDI safety system has been certified/validated, adjustment of the brake monitor shall not be done
without prior approval of the validation organization for both the brake monitor adjustment and the corresponding
adjustment of the safety distance. The validation organization shall in its installation validation, state that in what
circumstances, if any, the employer has advance approval for adjustment, when prior oral approval is appropriate and
when prior approval must be in writing. The adjustment shall be done under the supervision of an authorized person
whose qualifications include knowledge of safety distance requirements and experience with the brake system and its
adjustment. When brake wear or other factors extend press stopping time beyond the limit permitted by the brake
monitor, adjustment, repair, or maintenance shall be performed on the brake or other press system element that
extends the stopping time.
(iii) The brake monitor setting shall allow an increase of no more than 10 percent of the longest stopping time for the
press, or 10 milliseconds, whichever is longer, measured at the top of the stroke.
(6) Cycle control and control systems. (i) The control system on presses used in the PSDI mode shall meet the
applicable requirements of paragraphs (b)(7), (b)(8), (b)(13), and (c)(5) of this section.
(ii) The control system shall incorporate a means of dynamically monitoring for decoupling of the rotary position
indicating mechanism drive from the crankshaft. This monitor shall stop slide motion and prevent successive press
strokes if decoupling occurs, or if the monitor itself fails.
(iii) The mode selection means of paragraph (b)(7)(iii) of this section shall have at least one position for selection of
the PSDI mode. Where more than one interruption of the light sensing field is used in the initiation of a stroke, either
the mode selection means must have one position for each function, or a separate selection means shall be provided
which becomes operable when the PSDI mode is selected. Selection of PSDI mode and the number of
interruptions/withdrawals of the light sensing field required to initiate a press cycle shall be by means capable of
supervision by the employer.
(iv) A PSDI set-up/reset means shall be provided which requires an overt action by the operator, in addition to PSDI
mode selection, before operation of the press by means of PSDI can be started.
(v) An indicator visible to the operator and readily seen by the employer shall be provided which shall clearly indicate
that the system is set-up for cycling in the PSDI mode.
(vi) The control system shall incorporate a timer to deactivate PSDI when the press does not stroke within the period
of time set by the timer. The timer shall be manually adjustable, to a maximum time of 30 seconds. For any timer
setting greater than 15 seconds, the adjustment shall be made by the use of a special tool available only to
authorized persons. Following a deactivation of PSDI by the timer, the system shall make it necessary to reset the
set-up/reset means in order to reactivate the PSDI mode.
(vii) Reactivation of PSDI operation following deactivation of the PSDI mode from any other cause, such as activation
of the red color stop control required by paragraph (b)(7)(ii) of this section, interruption of the presence sensing field,
opening of an interlock, or reselection of the number of sensing field interruptions/withdrawals required to cycle the
press, shall require resetting of the set-up/reset means.
(viii) The control system shall incorporate an automatic means to prevent initiation or continued operation in the PSDI
mode unless the press drive motor is energized in the forward direction of crankshaft rotation.
(ix) The control design shall preclude any movement of the slide caused by operation of power on, power off, or
selector switches, or from checks for proper operations as required by paragraph (h)(6)(xiv) of this section.
(x) All components and subsystems of the control system shall be designed to operate together to provide total
control system compliance with the requirements of this section.
(xi) Where there is more than one operator of a press used for PSDI, each operator shall be protected by a separate,
independently functioning, presence sensing device. The control system shall require that each sensing field be
interrupted the selected number of times prior to initiating a stroke. Further, each operator shall be provided with a
set-up/reset means that meets the requirements of paragraph (h)(6) of this section, and which must be actuated to
initiate operation of the press in the PSDI mode.

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(xii) [Reserved]
(xiii) The Control system shall incorporate interlocks for supplemental guards, if used, which will prevent stroke
initiation or will stop a stroke in progress if any supplemental guard fails or is deactivated.
(xiv) The control system shall perform checks for proper operation of all cycle control logic element switches and
contacts at least once each cycle. Control elements shall be checked for correct status after power “on” and before
the initial PSDI stroke.
(xv) The control system shall have provisions for an “inch” operating means meeting the requirements of paragraph
(b)(7)(iv) of this section. Die-setting shall not be done in the PSDI mode. Production shall not be done in the “inch”
mode.
(xvi) The control system shall permit only a single stroke per initiation command.
(xvii) Controls with internally stored programs (e.g., mechanical, electro-mechanical, or electronic) shall meet the
requirements of paragraph (b)(13) of this section, and shall default to a predetermined safe condition in the event of
any single failure within the system. Programmable controllers which meet the requirements for controls with
internally stored programs stated above shall be permitted only if all logic elements affecting the safety system and
point of operation safety are internally stored and protected in such a manner that they cannot be altered or
manipulated by the user to an unsafe condition.
(7) Environmental requirements. Control components shall be selected, constructed, and connected together in such
a way as to withstand expected operational and environmental stresses, at least including those outlined in appendix
A. Such stresses shall not so affect the control system as to cause unsafe operation.
(8) Safety system. (i) Mechanical power presses used in the PSDI mode shall be operated under the control of a
safety system which, in addition to meeting the applicable requirements of paragraphs (b)(13) and (c)(5) and other
applicable provisions of this section, shall function such that a single failure or single operating error shall not cause
injury to personnel from point of operation hazards.
(ii) The safety system shall be designed, constructed, and arranged as an integral total system, including all elements
of the press, the controls, the safeguarding and any required supplemental safeguarding, and their interfaces with the
operator and that part of the environment which has effect on the protection against point of operation hazards.
(9) Safeguarding the point of operation. (i) The point of operation of presses operated in the PSDI mode shall be
safeguarded in accordance with the requirements of paragraph (c) of this section, except that the safety distance
requirements of paragraph (h)(9)(v) of this section shall be used for PSDI operation.
(ii)(A) PSDI shall be implemented only by use of light curtain (photo-electric) presence sensing devices which meet
the requirements of paragraph (c)(3)(iii)( c ) of this section unless the requirements of the following paragraph have
been met.
(B) Alternatives to photo-electric light curtains may be used for PSDI when the employer can demonstrate, through
tests and analysis by the employer or the manufacturer, that the alternative is as safe as the photo-electric light
curtain, that the alternative meets the conditions of this section, has the same long term reliability as light curtains and
can be integrated into the entire safety system as provided for in this section. Prior to use, both the employer and
manufacturer must certify that these requirements and all the other applicable requirements of this section are met
and these certifications must be validated by an OSHA-recognized third-party validation organization to meet these
additional requirements and all the other applicable requirements of paragraphs (a) through (h) and appendix A of
this section. Three months prior to the operation of any alternative system, the employer must notify the OSHA
Directorate of Safety Standards Programs of the name of the system to be installed, the manufacturer and the OSHArecognized third-party validation organization immediately. Upon request, the employer must make available to that
office all tests and analyses for OSHA review.
(iii) Individual sensing fields of presence sensing devices used to initiate strokes in the PSDI mode shall cover only
one side of the press.

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(iv) Light curtains used for PSDI operation shall have minimum object sensitivity not to exceed one and one-fourth
inches (31.75 mm). Where light curtain object sensitivity is user-adjustable, either discretely or continuously, design
features shall limit the minimum object sensitivity adjustment not to exceed one and one-fourth inches (31.75 mm).
Blanking of the sensing field is not permitted.
(v) The safety distance (Ds) from the sensing field of the presence sensing device to the point of operation shall be
greater than or equal to the distance determined by the formula:
Ds = Hs×(Ts+Tp+Tr+2Tm)+Dp

Where:
Ds = Minimum safety distance.
Hs = Hand speed constant of 63 inches per second (1.6 m/s).
Ts = Longest press stopping time, in seconds, computed by taking averages of multiple measurements at
each of three positions (45 degrees, 60 degrees, and 90 degrees) of crankshaft angular position; the
longest of the three averages is the stopping time to use. (Ts is defined as the sum of the kinetic energy
dissipation time plus the pneumatic/magnetic/hydraulic reaction time of the clutch/brake operating
mechanism(s).)
Tp = Longest presence sensing device response time, in seconds.
Tr = Longest response time, in seconds, of all interposing control elements between the presence
sensing device and the clutch/brake operating mechanism(s).
Tm = Increase in the press stopping time at the top of the stroke, in seconds, allowed by the brake
monitor for brake wear. The time increase allowed shall be limited to no more than 10 percent of the
longest press stopping time measured at the top of the stroke, or 10 milliseconds, whichever is longer.
Dp = Penetration depth factor, required to provide for possible penetration through the presence sensing
field by fingers or hand before detection occurs. The penetration depth factor shall be determined from
Graph h–1 using the minimum object sensitivity size.

14

View or download PDF
(vi) The presence sensing device location shall either be set at each tool change and set-up to provide at least the
minimum safety distance, or fixed in location to provide a safety distance greater than or equal to the minimum safety
distance for all tooling set-ups which are to be used on that press.
(vii) Where presence sensing device location is adjustable, adjustment shall require the use of a special tool available
only to authorized persons.
(viii) Supplemental safeguarding shall be used to protect all areas of access to the point of operation which are
unprotected by the PSDI presence sensing device. Such supplemental safeguarding shall consist of either additional
light curtain (photo-electric) presence sensing devices or other types of guards which meet the requirements of
paragraphs (c) and (h) of this section.
(A) Presence sensing devices used as supplemental safeguarding shall not initiate a press stroke, and shall conform
to the requirements of paragraph (c)(3)(iii) and other applicable provisions of this section, except that the safety
distance shall comply with paragraph (h)(9)(v) of this section.
(B) Guards used as supplemental safeguarding shall conform to the design, construction and application
requirements of paragraph (c)(2) of this section, and shall be interlocked with the press control to prevent press PSDI
operation if the guard fails, is removed, or is out of position.
(ix) Barriers shall be fixed to the press frame or bolster to prevent personnel from passing completely through the
sensing field, where safety distance or press configuration is such that personnel could pass through the PSDI
presence sensing field and assume a position where the point of operation could be accessed without detection by

15

the PSDI presence sensing device. As an alternative, supplemental presence sensing devices used only in the
safeguard mode may be provided. If used, these devices shall be located so as to detect all operator locations and
positions not detected by the PSDI sensing field, and shall prevent stroking or stop a stroke in process when any
supplemental sensing field(s) are interrupted.
(x) Hand tools. Where tools are used for feeding, removal of scrap, lubrication of parts, or removal of parts that stick
on the die in PSDI operations:
(A) The minimum diameter of the tool handle extension shall be greater than the minimum object sensitivity of the
presence sensing device(s) used to initiate press strokes; or
(B) The length of the hand tool shall be such as to ensure that the operator's hand will be detected for any safety
distance required by the press set-ups.
(10) Inspection and maintenance. (i) Any press equipped with presence sensing devices for use in PSDI, or for
supplemental safeguarding on presses used in the PSDI mode, shall be equipped with a test rod of diameter
specified by the presence sensing device manufacturer to represent the minimum object sensitivity of the sensing
field. Instructions for use of the test rod shall be noted on a label affixed to the presence sensing device.
(ii) The following checks shall be made at the beginning of each shift and whenever a die change is made.
(A) A check shall be performed using the test rod according to the presence sensing device manufacturer's
instructions to determine that the presence sensing device used for PSDI is operational.
(B) The safety distance shall be checked for compliance with (h)(9)(v) of this section.
(C) A check shall be made to determine that all supplemental safeguarding is in place. Where presence sensing
devices are used for supplemental safeguarding, a check for proper operation shall be performed using the test rod
according to the presence sensing device manufacturer's instructions.
(D) A check shall be made to assure that the barriers and/or supplemental presence sensing devices required by
paragraph (h)(9)(ix) of this section are operating properly.
(E) A system or visual check shall be made to verify correct counterbalance adjustment for die weight according to
the press manufacturer's instructions, when a press is equipped with a slide counterbalance system.
(iii) When presses used in the PSDI mode have flywheel or bullgear running on crankshaft mounted journals and
bearings, or a flywheel mounted on back shaft journals and bearings, periodic inspections following the press
manufacturer's recommendations shall be made to ascertain that bearings are in good working order, and that
automatic lubrication systems for these bearings (if automatic lubrication is provided) are supplying proper lubrication.
On presses with provision for manual lubrication of flywheel or bullgear bearings, lubrication shall be provided
according to the press manufacturer's recommendations.
(iv) Periodic inspections of clutch and brake mechanisms shall be performed to assure they are in proper operating
condition. The press manufacturer's recommendations shall be followed.
(v) When any check of the press, including those performed in accordance with the requirements of paragraphs
(h)(10)(ii), (iii) or (iv) of this section, reveals a condition of noncompliance, improper adjustment, or failure, the press
shall not be operated until the condition has been corrected by adjustment, replacement, or repair.
(vi) It shall be the responsibility of the employer to ensure the competence of personnel caring for, inspecting, and
maintaining power presses equipped for PSDI operation, through initial and periodic training.
(11) Safety system certification/validation. (i) Prior to the initial use of any mechanical press in the PSDI mode, two
sets of certification and validation are required:

16

(A) The design of the safety system required for the use of a press in the PSDI mode shall be certified and validated
prior to installation. The manufacturer's certification shall be validated by an OSHA-recognized third-party validation
organization to meet all applicable requirements of paragraphs (a) through (h) and appendix A of this section.
(B) After a press has been equipped with a safety system whose design has been certified and validated in
accordance with paragraph (h)(11)(i) of this section, the safety system installation shall be certified by the employer,
and then shall be validated by an OSHA-recognized third-party validation organization to meet all applicable
requirements of paragraphs (a) through (h) and appendix A of this section.
(ii) At least annually thereafter, the safety system on a mechanical power press used in the PSDI mode shall be
recertified by the employer and revalidated by an OSHA-recognized third-party validation organization to meet all
applicable requirements of paragraphs (a) through (h) and appendix A of this section. Any press whose safety system
has not been recertified and revalidated within the preceding 12 months shall be removed from service in the PSDI
mode until the safety system is recertified and revalidated.
(iii) A label shall be affixed to the press as part of each installation certification/validation and the most recent
recertification/revalidation. The label shall indicate the press serial number, the minimum safety distance (Ds)
required by paragraph (h)(9)(v) of this section, the fulfillment of design certification/validation, the employer's signed
certification, the identification of the OSHA-recognized third-party validation organization, its signed validation, and
the date the certification/validation and recertification/revalidation are issued.
(iv) Records of the installation certification and validation and the most recent recertification and revalidation shall be
maintained for each safety system equipped press by the employer as long as the press is in use. The records shall
include the manufacture and model number of each component and subsystem, the calculations of the safety
distance as required by paragraph (h)(9)(v) of this section, and the stopping time measurements required by
paragraph (h)(2)(ii) of this section. The most recent records shall be made available to OSHA upon request.
(v) The employer shall notify the OSHA-recognized third-party validation organization within five days whenever a
component or a subsystem of the safety system fails or modifications are made which may affect the safety of the
system. The failure of a critical component shall necessitate the removal of the safety system from service until it is
recertified and revalidated, except recertification by the employer without revalidation is permitted when a non-critical
component or subsystem is replaced by one of the same manufacture and design as the original, or determined by
the third-party validation organization to be equivalent by similarity analysis, as set forth in appendix A.
(vi) The employer shall notify the OSHA-recognized third-party validation organization within five days of the
occurrence of any point of operation injury while a press is used in the PSDI mode. This is in addition to the report of
injury required by paragraph (g) of this section; however, a copy of that report may be used for this purpose.
(12) Die setting and work set-up. (i) Die setting on presses used in the PSDI mode shall be performed in accordance
with paragraphs (d) and (h) of this section.
(ii) The PSDI mode shall not be used for die setting or set-up. An alternative manual cycle initiation and control
means shall be supplied for use in die setting which meets the requirements of paragraph (b)(7) of this section.
(iii) Following a die change, the safety distance, the proper application of supplemental safeguarding, and the slide
counterbalance adjustment (if the press is equipped with a counterbalance) shall be checked and maintained by
authorized persons whose qualifications include knowledge of the safety distance, supplemental safeguarding
requirements, and the manufacturer's specifications for counterbalance adjustment. Adjustment of the location of the
PSDI presence sensing device shall require use of a special tool available only to the authorized persons.
(13) Operator training. (i) The operator training required by paragraph (f)(2) of this section shall be provided to the
employee before the employee initially operates the press and as needed to maintain competence, but not less than
annually thereafter. It shall include instruction relative to the following items for presses used in the PSDI mode.
(A) The manufacturer's recommended test procedures for checking operation of the presence sensing device. This
shall include the use of the test rod required by paragraph (h)(10)(i) of this section.
(B) The safety distance required.

17

(C) The operation, function and performance of the PSDI mode.
(D) The requirements for hand tools that may be used in the PSDI mode.
(E) The severe consequences that can result if he or she attempts to circumvent or by-pass any of the safeguard or
operating functions of the PSDI system.
(ii) The employer shall certify that employees have been trained by preparing a certification record which includes the
identity of the person trained, the signature of the employer or the person who conducted the training, and the date
the training was completed. The certification record shall be prepared at the completion of training and shall be
maintained on file for the duration of the employee's employment. The certification record shall be made available
upon request to the Assistant Secretary for Occupational Safety and Health.

Appendix A to §1910.217—Mandatory Requirements for Certification/Validation of Safety Systems for
Presence Sensing Device Initiation of Mechanical Power Presses
Purpose
The purpose of the certification/validation of safety systems for presence sensing device initiation (PSDI)
of mechanical power presses is to ensure that the safety systems are designed, installed, and maintained
in accordance with all applicable requirements of 29 CFR 1910.217 (a) through (h) and this appendix A.
General
The certification/validation process shall utilize an independent third-party validation organization
recognized by OSHA in accordance with the requirements specified in appendix C of this section.
While the employer is responsible for assuring that the certification/validation requirements in
§1910.217(h)(11) are fulfilled, the design certification of PSDI safety systems may be initiated by
manufacturers, employers, and/or their representatives. The term manufacturers refers to the
manufacturer of any of the components of the safety system. An employer who assembles a PSDI safety
system would be a manufacturer as well as employer for purposes of this standard and appendix.
The certification/validation process includes two stages. For design certification, in the first stage, the
manufacturer (which can be an employer) certifies that the PSDI safety system meets the requirements of
29 CFR 1910.217 (a) through (h) and this appendix A, based on appropriate design criteria and tests. In
the second stage, the OSHA-recognized third-party validation organization validates that the PSDI safety
system meets the requirements of 29 CFR 1910.217 (a) through (h) and this appendix A and the
manufacturer's certification by reviewing the manufacturer's design and test data and performing any
additional reviews required by this standard or which it believes appropriate.
For installation certification/validation and annual recertification/revalidation, in the first stage the
employer certifies or recertifies that the employer is installing or utilizing a PSDI safety system validated
as meeting the design requirements of 29 CFR 1910.217 (a) through (h) and this appendix A by an
OSHA-recognized third-party validation organization and that the installation, operation and maintenance
meet the requirements of 29 CFR 1910.217 (a) through (h) and this appendix A. In the second stage, the
OSHA-recognized third-party validation organization validates or revalidates that the PSDI safety system
installation meets the requirements of 29 CFR 1910.217 (a) through (h) and this appendix A and the
employer's certification, by reviewing that the PSDI safety system has been certified; the employer's
certification, designs and tests, if any; the installation, operation, maintenance and training; and by
performing any additional tests and reviews which the validation organization believes is necessary.
Summary

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The certification/validation of safety systems for PSDI shall consider the press, controls, safeguards,
operator, and environment as an integrated system which shall comply with all of the requirements in 29
CFR 1910.217 (a) through (h) and this appendix A. The certification/validation process shall verify that the
safety system complies with the OSHA safety requirements as follows:
A. Design Certification/Validation
1. The major parts, components and subsystems used shall be defined by part number or serial number,
as appropriate, and by manufacturer to establish the configuration of the system.
2. The identified parts, components and subsystems shall be certified by the manufacturer to be able to
withstand the functional and operational environments of the PSDI safety system.
3. The total system design shall be certified by the manufacturer as complying with all requirements in 29
CFR 1910.217 (a) through (h) and this appendix A.
4. The third-party validation organization shall validate the manufacturer's certification under paragraphs 2
and 3.
B. Installation Certification/Validation
1. The employer shall certify that the PSDI safety system has been design certified and validated, that the
installation meets the operational and environmental requirements specified by the manufacturer, that the
installation drawings are accurate, and that the installation meets the requirements of 29 CFR 1910.217
(a) through (h) and this appendix A. (The operational and installation requirements of the PSDI safety
system may vary for different applications.)
2. The third-party validation organization shall validate the employer's certifications that the PSDI safety
system is design certified and validated, that the installation meets the installation and environmental
requirements specified by the manufacturer, and that the installation meets the requirements of 29 CFR
1910.217 (a) through (h) and this appendix A.
C. Recertification/Revalidation
1. The PSDI safety system shall remain under certification/validation for the shorter of one year or until
the system hardware is changed, modified or refurbished, or operating conditions are changed (including
environmental, application or facility changes), or a failure of a critical component has occurred.
2. Annually, or after a change specified in paragraph 1., the employer shall inspect and recertify the
installation as meeting the requirements set forth under B., Installation Certification/Validation.
3. The third-party validation organization, annually or after a change specified in paragraph 1., shall
validate the employer's certification that the requirements of paragraph B., Installation
Certification/Validation have been met.
(Note: Such changes in operational conditions as die changes or press relocations not involving
disassembly or revision to the safety system would not require recertification/revalidation.)
Certification/Validation Requirements
A. General Design Certification/Validation Requirements

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1. Certification/Validation Program Requirements. The manufacturer shall certify and the OSHArecognized third-party validation organization shall validate that:
(a) The design of components, subsystems, software and assemblies meets OSHA performance
requirements and are ready for the intended use; and
(b) The performance of combined subsystems meets OSHA's operational requirements.
2. Certification/Validation Program Level of Risk Evaluation Requirements. The manufacturer shall
evaluate and certify, and the OSHA-recognized third-party validation organization shall validate, the
design and operation of the safety system by determining conformance with the following:
a. The safety system shall have the ability to sustain a single failure or a single operating error and not
cause injury to personnel from point of operation hazards. Acceptable design features shall demonstrate,
in the following order or precedence, that:
(1) No single failure points may cause injury; or
(2) Redundancy, and comparison and/or diagnostic checking, exist for the critical items that may cause
injury, and the electrical, electronic, electromechanical and mechanical parts and components are
selected so that they can withstand operational and external environments. The safety factor and/or
derated percentage shall be specifically noted and complied with.
b. The manufacturer shall design, evaluate, test and certify, and the third-party validation organization
shall evaluate and validate, that the PSDI safety system meets appropriate requirements in the following
areas.
(1) Environmental Limits
(a) Temperature
(b) Relative humidity
(c) Vibration
(d) Fluid compatability with other materials
(2) Design Limits
(a) Power requirements
(b) Power transient tolerances
(c) Compatability of materials used
(d) Material stress tolerances and limits
(e) Stability to long term power fluctuations
(f) Sensitivity to signal acquisition
(g) Repeatability of measured parameter without inadvertent initiation of a press stroke

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(h) Operational life of components in cycles, hours, or both
(i) Electromagnetic tolerance to:
( 1 ) Specific operational wave lengths; and
( 2 ) Externally generated wave lengths
(3) New Design Certification/Validation. Design certification/validation for a new safety system, i.e., a new
design or new integration of specifically identified components and subsystems, would entail a single
certification/validation which would be applicable to all identical safety systems. It would not be necessary
to repeat the tests on individual safety systems of the same manufacture or design. Nor would it be
necessary to repeat these tests in the case of modifications where determined by the manufacturer and
validated by the third-party validation organization to be equivalent by similarity analysis. Minor
modifications not affecting the safety of the system may be made by the manufacturer without
revalidation.
Substantial modifications would require testing as a new safety system, as deemed necessary by the
validation organization.
B. Additional Detailed Design Certification/Validation Requirements
1. General. The manufacturer or the manufacturer's representative shall certify to and submit to an
OSHA-recognized third-party validation organization the documentation necessary to demonstrate that
the PSDI safety system design is in full compliance with the requirements of 29 CFR 1910.217(a)–(h) and
this appendix A, as applicable, by means of analysis, tests, or combination of both, establishing that the
following additional certification/validation requirements are fulfilled.
2. Reaction Times. For the purpose of demonstrating compliance with the reaction time required by
§1910.217(h), the tests shall use the following definitions and requirements:
a. Reaction time means the time, in seconds, it takes the signal, required to activate/deactivate the
system, to travel through the system, measured from the time of signal initiation to the time the function
being measured is completed.
b. Full stop or No movement of the slide or ram means when the crankshaft rotation has slowed to two or
less revolutions per minute, just before stopping completely.
c. Function completion means for, electrical, electromechanical and electronic devices, when the circuit
produces a change of state in the output element of the device.
d. When the change of state is motion, the measurement shall be made at the completion of the motion.
e. The generation of the test signal introduced into the system for measuring reaction time shall be such
that the initiation time can be established with an error of less than 0.5 percent of the reaction time
measured.
f. The instrument used to measure reaction time shall be calibrated to be accurate to within 0.001 second.
3. Compliance with §1910.217(h)(2)(ii). For compliance with these requirements, the average value of the
stopping time, Ts, shall be the arithmetic mean of at least 25 stops for each stop angle initiation
measured with the brake and/or clutch unused, 50 percent worn, and 90 percent worn. The
recommendations of the brake system manufacturer shall be used to simulate or estimate the brake

21

wear. The manufacturer's recommended minimum lining depth shall be identified and documented, and
an evaluation made that the minimum depth will not be exceeded before the next (annual)
recertification/revalidation. A correlation of the brake and/or clutch degradation based on the above tests
and/or estimates shall be made and documented. The results shall document the conditions under which
the brake and/or clutch will and will not comply with the requirement. Based upon this determination, a
scale shall be developed to indicate the allowable 10 percent of the stopping time at the top of the stroke
for slide or ram overtravel due to brake wear. The scale shall be marked to indicate that brake adjustment
and/or replacement is required. The explanation and use of the scale shall be documented.
The test specification and procedure shall be submitted to the validation organization for review and
validation prior to the test. The validation organization representative shall witness at least one set of
tests.
4. Compliance with §§1910.217(h)(5)(iii) and (h)(9)(v). Each reaction time required to calculate the Safety
Distance, including the brake monitor setting, shall be documented in separate reaction time tests. These
tests shall specify the acceptable tolerance band sufficient to assure that tolerance build-up will not
render the safety distance unsafe.
a. Integrated test of the press fully equipped to operate in the PSDI mode shall be conducted to establish
the total system reaction time.
b. Brakes which are the adjustable type shall be adjusted properly before the test.
5. Compliance with §1910.217(h)(2)(iii). a. Prior to conducting the brake system test required by
paragraph (h)(2)(ii), a visual check shall be made of the springs. The visual check shall include a
determination that the spring housing or rod does not show damage sufficient to degrade the structural
integrity of the unit, and the spring does not show any tendency to interleave.
b. Any detected broken or unserviceable springs shall be replaced before the test is conducted. The test
shall be considered successful if the stopping time remains within that which is determined by paragraph
(h)(9)(v) for the safety distance setting. If the increase in press stopping time exceeds the brake monitor
setting limit defined in paragraph (h)(5)(iii), the test shall be considered unsuccessful, and the cause of
the excessive stopping time shall be investigated. It shall be ascertained that the springs have not been
broken and that they are functioning properly.
6. Compliance with §1910.217(h)(7). a. Tests which are conducted by the manufacturers of electrical
components to establish stress, life, temperature and loading limits must be tests which are in compliance
with the provisions of the National Electrical Code.
b. Electrical and/or electronic cards or boards assembled with discreet components shall be considered a
subsystem and shall require separate testing that the subsystems do not degrade in any of the following
conditions:
(1) Ambient temperature variation from −20 °C to +50 °C.
(2) Ambient relative humidity of 99 percent.
(3) Vibration of 45G for one millisecond per stroke when the item is to be mounted on the press frame.
(4) Electromagnetic interference at the same wavelengths used for the radiation sensing field, at the
power line frequency fundamental and harmonics, and also from outogenous radiation due to system
switching.

22

(5) Electrical power supply variations of ±15 percent.
c. The manufacturer shall specify the test requirements and procedures from existing consensus tests in
compliance with the provisions of the National Electrical Code.
d. Tests designed by the manufacturer shall be made available upon request to the validation
organization. The validation organization representative shall witness at least one set of each of these
tests.
7. Compliance with §1910.217(h)(9)(iv). a. The manufacturer shall design a test to demonstrate that the
prescribed minimum object sensitivity of the presence sensing device is met.
b. The test specifications and procedures shall be made available upon request to the validation
organization.
8. Compliance with §1910.217(h)(9)(x). a. The manufacturer shall design a test(s) to establish the hand
tool extension diameters allowed for variations in minimum object sensitivity response.
b. The test(s) shall document the range of object diameter sizes which will produce both single and
double break conditions.
c. The test(s) specifications and procedures shall be made available upon request to the validation
organization.
9. Integrated Tests Certification/Validation. a. The manufacturer shall design a set of integrated tests to
demonstrate compliance with the following requirements:
Sections 1910.217(h)(6) (ii); (iii); (iv); (v); (vi); (vii); (viii); (ix); (xi); (xii); (xiii); (xiv); (xv); and (xvii).
b. The integrated test specifications and procedures shall be made available to the validation
organization.
10. Analysis. a. The manufacturer shall submit to the validation organization the technical analysis such
as Hazard Analysis, Failure Mode and Effect Analysis, Stress Analysis, Component and Material
Selection Analysis, Fluid Compatability, and/or other analyses which may be necessary to demonstrate,
compliance with the following requirements:
Sections 1910.217(h)(8) (i) and (ii); (h)(2) (ii) and (iii); (h)(3)(i) (A) and (C), and (ii); (h)(5) (i), (ii) and (iii);
(h)(6) (i), (iii), (iv), (vi), (vii), (viii), (ix), (x), (xi), (xiii), (xiv), (xv), (xvi), and (xvii); (h)(7) (i) and (ii); (h)(9) (iv),
(v), (viii), (ix) and (x); (h)(10) (i) and (ii).
11. Types of Tests Acceptable for Certification/Validation. a. Test results obtained from development
testing may be used to certify/validate the design.
b. The test results shall provide the engineering data necessary to establish confidence that the hardware
and software will meet specifications, the manufacturing process has adequate quality control and the
data acquired was used to establish processes, procedures, and test levels supporting subsequent
hardware design, production, installation and maintenance.
12. Validation for Design Certification/Validation. If, after review of all documentation, tests, analyses,
manufacturer's certifications, and any additional tests which the third-party validation organization
believes are necessary, the third-party validation organization determines that the PSDI safety system is

23

in full compliance with the applicable requirements of 29 CFR 1910.217(a) through (h) and this appendix
A, it shall validate the manufacturer's certification that it so meets the stated requirements.
C. Installation Certification/Validation Requirements
1. The employer shall evaluate and test the PSDI system installation, shall submit to the OSHArecognized third-party validation organization the necessary supporting documentation, and shall certify
that the requirements of §1910.217(a) through (h) and this appendix A have been met and that the
installation is proper.
2. The OSHA-recognized third-party validation organization shall conduct tests, and/or review and
evaluate the employer's installation tests, documentation and representations. If it so determines, it shall
validate the employer's certification that the PSDI safety system is in full conformance with all
requirements of 29 CFR 1910.217(a) through (h) and this appendix A.
D. Recertification/Revalidation Requirements
1. A PSDI safety system which has received installation certification/validation shall undergo
recertification/revalidation the earlier of:
a. Each time the systems hardware is significantly changed, modified, or refurbished;
b. Each time the operational conditions are significantly changed (including environmental, application or
facility changes, but excluding such changes as die changes or press relocations not involving revision to
the safety system);
c. When a failure of a significant component has occurred or a change has been made which may affect
safety; or
d. When one year has elapsed since the installation certification/validation or the last
recertification/revalidation.
2. Conduct or recertification/revalidation. The employer shall evaluate and test the PSDI safety system
installation, shall submit to the OSHA-recognized third-party validation organization the necessary
supporting documentation, and shall recertify that the requirements of §1910.217(a) through (h) and this
appendix are being met. The documentation shall include, but not be limited to, the following items:
a. Demonstration of a thorough inspection of the entire press and PSDI safety system to ascertain that
the installation, components and safeguarding have not been changed, modified or tampered with since
the installation certification/validation or last recertification/revalidation was made.
b. Demonstrations that such adjustments as may be needed (such as to the brake monitor setting) have
been accomplished with proper changes made in the records and on such notices as are located on the
press and safety system.
c. Demonstration that review has been made of the reports covering the design certification/validation, the
installation certification/validation, and all recertification/revalidations, in order to detect any degradation
to an unsafe condition, and that necessary changes have been made to restore the safety system to
previous certification/validation levels.
3. The OSHA-recognized third-party validation organization shall conduct tests, and/or review and
evaluate the employer's installation, tests, documentation and representations. If it so determines, it shall

24

revalidate the employer's recertification that the PSDI system is in full conformance with all requirements
of 29 CFR 1910.217(a) through (h) and this appendix A.
Appendix B to §1910.217—Nonmandatory Guidelines for Certification/Validation of Safety Systems for
Presence Sensing Device Initiation of Mechanical Power Presses
Objectives
This appendix provides employers, manufacturers, and their representatives, with nonmandatory
guidelines for use in developing certification documents. Employers and manufacturers are encouraged
to recommend other approaches if there is a potential for improving safety and reducing cost. The
guidelines apply to certification/validation activity from design evaluation through the completion of the
installation test and the annual recertification/revalidation tests.
General Guidelines
A. The certification/validation process should confirm that hazards identified by hazard analysis, (HA),
failure mode effect analysis (FMEA), and other system analyses have been eliminated by design or
reduced to an acceptable level through the use of appropriate design features, safety devices, warning
devices, or special procedures. The certification/validation process should also confirm that residual
hazards identified by operational analysis are addressed by warning, labeling safety instructions or other
appropriate means.
B. The objective of the certification/validation program is to demonstrate and document that the system
satisfies specification and operational requirements for safe operations.
Quality Control
The safety attributes of a certified/validated PSDI safety system are more likely to be maintained if the
quality of the system and its parts, components and subsystem is consistently controlled. Each
manufacturer supplying parts, components, subsystems, and assemblies needs to maintain the quality of
the product, and each employer needs to maintain the system in a non-degraded condition.
Analysis Guidelines
A. Certification/validation of hardware design below the system level should be accomplished by test
and/or analysis.
B. Analytical methods may be used in lieu of, in combination with, or in support of tests to satisfy
specification requirements.
C. Analyses may be used for certification/validation when existing data are available or when test is not
feasible.
D. Similarity analysis may be used in lieu of tests where it can be shown that the article is similar in
design, manufacturing process, and quality control to another article that was previously
certified/validated in accordance with equivalent or more stringent criteria. If previous design, history and
application are considered to be similar, but not equal to or more exacting than earlier experiences, the
additional or partial certification/validation tests should concentrate on the areas of changed or increased
requirements.
Analysis Reports

25

The analysis reports should identify: (1) The basis for the analysis; (2) the hardware or software items
analyzed; (3) conclusions; (4) safety factors; and (5) limit of the analysis. The assumptions made during
the analysis should be clearly stated and a description of the effects of these assumptions on the
conclusions and limits should be included.
Certification/validation by similarity analysis reports should identify, in addition to the above, application of
the part, component or subsystem for which certification/validation is being sought as well as data from
previous usage establishing adequacy of the item. Similarity analysis should not be accepted when the
internal and external stresses on the item being certified/validated are not defined.
Usage experience should also include failure data supporting adequacy of the design.
Appendix C to §1910.217—Mandatory Requirements for OSHA Recognition of Third-Party Validation
Organizations for the PSDI Standard
This appendix prescribes mandatory requirements and procedures for OSHA recognition of third-party
validation organizations to validate employer and manufacturer certifications that their equipment and
practices meet the requirements of the PSDI standard. The scope of the appendix includes the three
categories of certification/validation required by the PSDI standard: Design Certification/Validation,
Installation Certification/Validation, and Annual Recertification/Revalidation.
If further detailing of these provisions will assist the validation organization or OSHA in this activity, this
detailing will be done through appropriate OSHA Program Directives.
I. Procedure for OSHA Recognition of Validation Organizations
A. Applications
1. Eligibility. a. Any person or organization considering itself capable of conducting a PSDI-related thirdparty validation function may apply for OSHA recognition.
b. However, in determining eligibility for a foreign-based third-party validation organization, OSHA shall
take into consideration whether there is reciprocity of treatment by the foreign government after
consultation with relevant U.S. government agencies.
2. Content of application. a. The application shall identify the scope of the validation activity for which the
applicant wishes to be recognized, based on one of the following alternatives:
(1) Design Certification/Validation, Installation Certification/Validation, and Annual
Recertification/Revalidation;
(2) Design Certification/Validation only; or
(3) Installation/Certification/Validation and Annual Recertification/Revalidation.
b. The application shall provide information demonstrating that it and any validating laboratory utilized
meet the qualifications set forth in section II of this appendix.
c. The applicant shall provide information demonstrating that it and any validating laboratory utilized meet
the program requirements set forth in section III of this appendix.

26

d. The applicant shall identify the test methods it or the validating laboratory will use to test or judge the
components and operations of the PSDI safety system required to be tested by the PSDI standard and
appendix A, and shall specify the reasons the test methods are appropriate.
e. The applicant may include whatever enclosures, attachments, or exhibits the applicant deems
appropriate. The application need not be submitted on a Federal form.
f. The applicant shall certify that the information submitted is accurate.
3. Filing office location. The application shall be filed with: PSDI Certification/Validation Program, Office of
Variance Determination, Occupational Safety and Health Administration, U.S. Department of Labor,
Room N3653, 200 Constitution Avenue, NW., Washington, DC 20210.
4. Amendments and withdrawals. a. An application may be revised by an applicant at any time prior to the
completion of the final staff recommendation.
b. An application may be withdrawn by an applicant, without prejudice, at any time prior to the final
decision by the Assistant Secretary in paragraph I.B.8.b.(4) of this appendix.
B. Review and Decision Process
1. Acceptance and field inspection. All applications submitted will be accepted by OSHA, and their receipt
acknowledged in writing. After receipt of an application, OSHA may request additional information if it
believes information relevant to the requirements for recognition have been omitted. OSHA may inspect
the facilities of the third-party validation organization and any validating laboratory, and while there shall
review any additional documentation underlying the application. A report shall be made of each field
inspection.
2. Requirements for recognition. The requirements for OSHA recognition of a third-party validation
organization for the PSDI standard are that the program has fulfilled the requirements of section II of this
appendix for qualifications and of section III of this appendix for program requirements, and the program
has identified appropriate test and analysis methods to meet the requirements of the PSDI standard and
appendix A.
3. Preliminary approval. If, after review of the application, any additional information, and the inspection
report, the applicant and any validating laboratory appear to have met the requirements for recognition, a
written recommendation shall be submitted by the responsible OSHA personnel to the Assistant
Secretary to approve the application with a supporting explanation.
4. Preliminary disapproval. If, after review of the application, additional information, and inspection report,
the applicant does not appear to have met the requirements for recognition, the Director of the PSDI
certification/validation program shall notify the applicant in writing, listing the specific requirements of this
appendix which the applicant has not met, and the reasons.
5. Revision of application. After receipt of a notification of preliminary disapproval, the applicant may
submit a revised application for further review by OSHA pursuant to subsection I.B. of this appendix or
may request that the original application be submitted to the Assistant Secretary with a statement of
reasons supplied by the applicant as to why the application should be approved.
6. Preliminary decision by Assistant Secretary. a. The Assistant Secretary, or a special designee for this
purpose, will make a preliminary decision whether the applicant has met the requirements for recognition
based on the completed application file and the written staff recommendation, as well as the statement of
reasons by the applicant if there is a recommendation of disapproval.

27

b. This preliminary decision will be sent to the applicant and subsequently published in
the Federal Register .
7. Public review and comment period. a. The Federal Register notice of preliminary decision will provide
a period of not less than 60 calendar days for the written comments on the applicant's fulfillment of the
requirements for recognition. The application, supporting documents, staff recommendation, statement of
applicant's reasons, and any comments received, will be available for public inspection in the OSHA
Docket Office.
b. If the preliminary decision is in favor of recognition, a member of the public, or if the preliminary
decision is against recognition, the applicant may request a public hearing by the close of the comment
period, if it supplies detailed reasons and evidence challenging the basis of the Assistant Secretary's
preliminary decision and justifying the need for a public hearing to bring out evidence which could not be
effectively supplied through written submissions.
8. Final decision by Assistant Secretary —a. Without hearing. If there are no valid requests for a hearing,
based on the application, supporting documents, staff recommendation, evidence and public comment,
the Assistant Secretary shall issue the final decision (including reasons) of the Department of Labor on
whether the applicant has demonstrated by a preponderance of the evidence that it meets the
requirements for recognition.
b. After hearing. If there is a valid request for a hearing pursuant to paragraph I.B.7.b. of this appendix,
the following procedures will be used:
(1) The Assistant Secretary will issue a notice of hearing before an administrative law judge of the
Department of Labor pursuant to the rules specified in 29 CFR part 1905, subpart C.
(2) After the hearing, pursuant to subpart C, the administrative law judge shall issue a decision (including
reasons) based on the application, the supporting documentation, the staff recommendation, the public
comments and the evidence submitted during the hearing (the record), stating whether it has been
demonstrated, based on a preponderance of evidence, that the applicant meets the requirements for
recognition. If no exceptions are filed, this is the final decision of the Department of Labor.
(3) Upon issuance of the decision, any party to the hearing may file exceptions within 20 days pursuant to
subpart C. If exceptions are filed, the administrative law judge shall forward the decision, exceptions and
record to the Assistant Secretary for the final decision on the application.
(4) The Assistant Secretary shall review the record, the decision by the administrative law judge, and the
exceptions. Based on this, the Assistant Secretary shall issue the final decision (including reasons) of the
Department of Labor stating whether the applicant has demonstrated by a preponderance of evidence
that it meets the requirements for recognition.
b. Publication. A notification of the final decision shall be published in the Federal Register .
C. Terms and Conditions of Recognition, Renewal and Revocation
1. The following terms and conditions shall be part of every recognition:
a. The recognition of any validation organization will be evidenced by a letter of recognition from OSHA.
The letter will provide the specific details of the scope of the OSHA recognition as well as any conditions
imposed by OSHA, including any Federal monitoring requirements.

28

b. The recognition of each validation organization will be valid for five years, unless terminated before or
renewed after the expiration of the period. The dates of the period of recognition will be stated in the
recognition letter.
c. The recognized validation organization shall continue to satisfy all the requirements of this appendix
and the letter of recognition during the period of recognition.
2. A recognized validation organization may change a test method of the PSDI safety system
certification/validation program by notifying the Assistant Secretary of the change, certifying that the
revised method will be at least as effective as the prior method, and providing the supporting data upon
which its conclusions are based.
3. A recognized validation organization may renew its recognition by filing a renewal request at the
address in paragraph I.A.3. of this appendix, above, not less than 180 calendar days, nor more than one
year, before the expiration date of its current recognition. When a recognized validation organization has
filed such a renewal request, its current recognition will not expire until a final decision has been made on
the request. The renewal request will be processed in accordance with subsection I.B. of this appendix,
above, except that a reinspection is not required but may be performed by OSHA. A hearing will be
granted to an objecting member of the public if evidence of failure to meet the requirements of this
appendix is supplied to OSHA.
4. A recognized validation organization may apply to OSHA for an expansion of its current recognition to
cover other categories of PSDI certification/validation in addition to those included in the current
recognition. The application for expansion will be acted upon and processed by OSHA in accordance with
subsection I.B. of this appendix, subject to the possible reinspection exception. If the validation
organization has been recognized for more than one year, meets the requirements for expansion of
recognition, and there is no evidence that the recognized validation organization has not been following
the requirements of this appendix and the letter of recognition, an expansion will normally be granted. A
hearing will be granted to an objecting member of the public only if evidence of failure to meet the
requirements of this appendix is supplied to OSHA.
5. A recognized validation organization may voluntarily terminate its recognition, either in its entirety or
with respect to any area covered in its recognition, by giving written notice to OSHA at any time. The
written notice shall indicate the termination date. A validation organization may not terminate its
installation certification and recertification validation functions earlier than either one year from the date of
the written notice, or the date on which another recognized validation organization is able to perform the
validation of installation certification and recertification.
6.a. OSHA may revoke its recognition of a validation organization if its program either has failed to
continue to satisfy the requirements of this appendix or its letter of recognition, has not been performing
the validation functions required by the PSDI standard and appendix A, or has misrepresented itself in its
applications. Before proposing to revoke recognition, the Agency will notify the recognized validation
organization of the basis of the proposed revocation and will allow rebuttal or correction of the alleged
deficiencies. If the deficiencies are not corrected, OSHA may revoke recognition, effective in 60 days,
unless the validation organization requests a hearing within that time.
b. If a hearing is requested, it shall be held before an administrative law judge of the Department of Labor
pursuant to the rules specified in 29 CFR part 1905, subpart C.
c. The parties shall be OSHA and the recognized validation organization. The decision shall be made
pursuant to the procedures specified in paragraphs I.B.8.b.(2) through (4) of this appendix except that the
burden of proof shall be on OSHA to demonstrate by a preponderance of the evidence that the
recognition should be revoked because the validation organization either is not meeting the requirements

29

for recognition, has not been performing the validation functions required by the PSDI standard and
appendix A, or has misrepresented itself in its applications.
D. Provisions of OSHA Recognition
Each recognized third-party validation organization and its validating laboratories shall:
1. Allow OSHA to conduct unscheduled reviews or on-site audits of it or the validating laboratories on
matters relevant to PSDI, and cooperate in the conduct of these reviews and audits;
2. Agree to terms and conditions established by OSHA in the grant of recognition on matters such as
exchange of data, submission of accident reports, and assistance in studies for improving PSDI or the
certification/validation process.
II. Qualifications
The third-party validation organization, the validating laboratory, and the employees of each shall meet
the requirements set forth in this section of this appendix.
A. Experience of Validation Organization
1. The third-party validation organization shall have legal authority to perform certification/validation
activities.
2. The validation organization shall demonstrate competence and experience in either power press
design, manufacture or use, or testing, quality control or certification/validation of equipment comparable
to power presses and associated control systems.
3. The validation organization shall demonstrate a capability for selecting, reviewing, and/or validating
appropriate standards and test methods to be used for validating the certification of PSDI safety systems,
as well as for reviewing judgements on the safety of PSDI safety systems and their conformance with the
requirements of this section.
4. The validating organization may utilize the competence, experience, and capability of its employees to
demonstrate this competence, experience and capability.
B. Independence of Validation Organization
1. The validation organization shall demonstrate that:
a. It is financially capable to conduct the work;
b. It is free of direct influence or control by manufacturers, suppliers, vendors, representatives of
employers and employees, and employer or employee organizations; and
c. Its employees are secure from discharge resulting from pressures from manufacturers, suppliers,
vendors, employers or employee representatives.
2. A validation organization may be considered independent even if it has ties with manufacturers,
employers or employee representatives if these ties are with at least two of these three groups; it has a
board of directors (or equivalent leadership responsible for the certification/validation activities) which

30

includes representatives of the three groups; and it has a binding commitment of funding for a period of
three years or more.
C. Validating Laboratory
The validation organization's laboratory (which organizationally may be a part of the third-party validation
organization):
1. Shall have legal authority to perform the validation of certification;
2. Shall be free of operational control and influence of manufacturers, suppliers, vendors, employers, or
employee representatives that would impair its integrity of performance; and
3. Shall not engage in the design, manufacture, sale, promotion, or use of the certified equipment.
D. Facilities and Equipment
The validation organization's validating laboratory shall have available all testing facilities and necessary
test and inspection equipment relevant to the validation of the certification of PSDI safety systems,
installations and operations.
E. Personnel
The validation organization and the validating laboratory shall be adequately staffed by personnel who
are qualified by technical training and/or experience to conduct the validation of the certification of PSDI
safety systems.
1. The validation organization shall assign overall responsibility for the validation of PSDI certification to
an Administrative Director. Minimum requirements for this position are a Bachelor's degree and five years
professional experience, at least one of which shall have been in responsible charge of a function in the
areas of power press design or manufacture or a broad range of power press use, or in the areas of
testing, quality control, or certification/validation of equipment comparable to power presses or their
associated control systems.
2. The validating laboratory, if a separate organization from the validation organization, shall assign
technical responsibility for the validation of PSDI certification to a Technical Director. Minimum
requirements for this position are a Bachelor's degree in a technical field and five years of professional
experience, at least one of which shall have been in responsible charge of a function in the area of
testing, quality control or certification/validation of equipment comparable to power presses or their
associated control systems.
3. If the validation organization and the validating laboratory are the same organization, the administrative
and technical responsibilities may be combined in a single position, with minimum requirements as
described in E.1. and 2. for the combined position.
4. The validation organization and validating laboratory shall have adequate administrative and technical
staffs to conduct the validation of the certification of PSDI safety systems.
F. Certification/Validation Mark or Logo
1. The validation organization or the validating laboratory shall own a registered certification/validation
mark or logo.

31

2. The mark or logo shall be suitable for incorporation into the label required by paragraph (h)(11)(iii) of
this section.
III. Program Requirements
A. Test and Certification/Validation Procedures
1. The validation organization and/or validating laboratory shall have established written procedures for
test and certification/validation of PSDI safety systems. The procedures shall be based on pertinent
OSHA standards and test methods, or other publicly available standards and test methods generally
recognized as appropriate in the field, such as national consensus standards or published standards of
professional societies or trade associations.
2. The written procedures for test and certification/validation of PSDI systems, and the standards and test
methods on which they are based, shall be reproducible and be available to OSHA and to the public upon
request.
B. Test Reports
1. A test report shall be prepared for each PSDI safety system that is tested. The test report shall be
signed by a technical staff representative and the Technical Director.
2. The test report shall include the following:
a. Name of manufacturer and catalog or model number of each subsystem or major component.
b. Identification and description of test methods or procedures used. (This may be through reference to
published sources which describe the test methods or procedures used.)
c. Results of all tests performed.
d. All safety distance calculations.
3. A copy of the test report shall be maintained on file at the validation organization and/or validating
laboratory, and shall be available to OSHA upon request.
C. Certification/Validation Reports
1. A certification/validation report shall be prepared for each PSDI safety system for which the certification
is validated. The certification/validation report shall be signed by the Administrative Director and the
Technical Director.
2. The certification/validation report shall include the following:
a. Name of manufacturer and catalog or model number of each subsystem or major component.
b. Results of all tests which serve as the basis for the certification.
c. All safety distance calculations.
d. Statement that the safety system conforms with all requirements of the PSDI standard and appendix A.

32

3. A copy of the certification/validation report shall be maintained on file at the validation organization
and/or validating laboratory, and shall be available to the public upon request.
4. A copy of the certification/validation report shall be submitted to OSHA within 30 days of its completion.
D. Publications System
The validation organization shall make available upon request a list of PSDI safety systems which have
been certified/validated by the program.
E. Follow-up Activities
1. The validation organization or validating laboratory shall have a follow-up system for inspecting or
testing manufacturer's production of design certified/validated PSDI safety system components and
subassemblies where deemed appropriate by the validation organization.
2. The validation organization shall notify the appropriate product manufacturer(s) of any reports from
employers of point of operation injuries which occur while a press is operated in a PSDI mode.
F. Records
The validation organization or validating laboratory shall maintain a record of each certification/validation
of a PSDI safety system, including manufacturer and/or employer certification documentation, test and
working data, test report, certification/validation report, any follow-up inspections or testing, and reports of
equipment failures, any reports of accidents involving the equipment, and any other pertinent information.
These records shall be available for inspection by OSHA and OSHA State Plan offices.
G. Dispute Resolution Procedures
1. The validation organization shall have a reasonable written procedure for acknowledging and
processing appeals or complaints from program participants (manufacturers, producers, suppliers,
vendors and employers) as well as other interested parties (employees or their representatives, safety
personnel, government agencies, etc.), concerning certification or validation.
2. The validation organization may charge any complainant the reasonable charge for repeating tests
needed for the resolution of disputes.
Appendix D to §1910.217—Nonmandatory Supplementary Information
This appendix provides nonmandatory supplementary information and guidelines to assist in the
understanding and use of 29 CFR 1910.217(h) to allow presence sensing device initiation (PSDI) of
mechanical power presses. Although this appendix as such is not mandatory, it references sections and
requirements which are made mandatory by other parts of the PSDI standard and appendices.
1. General
OSHA intends that PSDI continue to be prohibited where present state-of-the-art technology will not allow
it to be done safely. Only part revolution type mechanical power presses are approved for PSDI. Similarly,
only presses with a configuration such that a person's body cannot completely enter the bed area are
approved for PSDI.
2. Brake and Clutch

33

Flexible steel band brakes do not possess a long-term reliability against structural failure as compared to
other types of brakes, and therefore are not acceptable on presses used in the PSDI mode of operation.
Fast and consistent stopping times are important to safety for the PSDI mode of operation. Consistency
of braking action is enhanced by high brake torque. The requirement in paragraph (h)(2)(ii) defines a high
torque capability which should ensure fast and consistent stopping times.
Brake design parameters important to PSDI are high torque, low moment of inertia, low air volume (if
pneumatic) mechanisms, non-interleaving engagement springs, and structural integrity which is enhanced
by over-design. The requirement in paragrpah (h)(2)(iii) reduces the possibility of significantly increased
stopping time if a spring breaks.
As an added precaution to the requirements in paragraph (h)(2)(iii), brake adjustment locking means
should be secured. Where brake springs are externally accessible, lock nuts or other means may be
provided to reduce the possibility of backing off of the compression nut which holds the springs in place.
3. Pneumatic Systems
Elevated clutch/brake air pressure results in longer stopping time. The requirement in paragraph (h)(3)(i)(
C ) is intended to prevent degradation in stoping speed from higher air pressure. Higher pressures may
be permitted, however, to increase clutch torque to free “jammed” dies, provided positive measures are
provided to prevent the higher pressure at other times.
4. Flywheels and Bearings
Lubrication of bearings is considered the single greatest deterrent to their failure. The manufacturer's
recommended procedures for maintenance and inspection should be closely followed.
5. Brake Monitoring
The approval of brake monitor adjustments, as required in paragraph (h)(5)(ii), is not considered a
recertification, and does not necessarily involve an on-site inspection by a representative of the validation
organization. It is expected that the brake monitor adjustment normally could be evaluated on the basis of
the effect on the safety system certification/validation documentation retained by the validation
organization.
Use of a brake monitor does not eliminate the need for periodic brake inspection and maintenance to
reduce the possibility of catastrophic failures.
6. Cycle Control and Control Systems
The PSDI set-up/reset means required by paragraph (h)(6)(iv) may be initiated by the actuation of a
special momentary pushbutton or by the actuation of a special momentary pushbutton and the initiation of
a first stroke with two hand controls.
It would normally be preferable to limit the adjustment of the time required in paragraph (h)(6)(vi) to a
maximum of 15 seconds. However, where an operator must do many operations outside the press, such
as lubricating, trimming, deburring, etc., a longer interval up to 30 seconds is permitted.
When a press is equipped for PSDI operation, it is recommended that the presence sensing device be
active as a guarding device in other production modes. This should enhance the reliability of the device
and ensure that it remains operable.

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An acceptable method for interlocking supplemental guards as required by paragraph (h)(6)(xiii) would be
to incorporate the supplemental guard and the PSDI presence sensing device into a hinged arrangement
in which the alignment of the presence sensing device serves, in effect, as the interlock. If the
supplemental guards are moved, the presence sensing device would become misaligned and the press
control would be deactivated. No extra microswitches or interlocking sensors would be required.
Paragraph (h)(6)(xv) of the standard requires that the control system have provisions for an “inch”
operating means; that die-setting not be done in the PSDI mode; and that production not be done in the
“inch” mode. It should be noted that the sensing device would be by-passed in the “inch” mode. For that
reason, the prohibitions against die-setting in the PSDI mode, and against production in the “inch” mode
are cited to emphasize that “inch” operation is of reduced safety and is not compatible with PSDI or other
production modes.
7. Environmental Requirements
It is the intent of paragraph (h)(7) that control components be provided with inherent design protection
against operating stresses and environmental factors affecting safety and reliability.
8. Safety system
The safety system provision continues the concept of paragraph (b)(13) that the probability of two
independent failures in the length of time required to make one press cycle is so remote as to be a
negligible risk factor in the total array of equipment and human factors. The emphasis is on an integrated
total system including all elements affecting point of operation safety.
It should be noted that this does not require redundancy for press components such as structural
elements, clutch/brake mechanisms, plates, etc., for which adequate reliability may be achieved by
proper design, maintenance, and inspection.
9. Safeguarding the Point of Operation
The intent of paragraph (h)(9)(iii) is to prohibit use of mirrors to “bend” a single light curtain sensing field
around corners to cover more than one side of a press. This prohibition is needed to increase the
reliability of the presence sensing device in initiating a stroke only when the desired work motion has
been completed.
Object sensitivity describes the capability of a presence sensing device to detect an object in the sensing
field, expressed as the linear measurement of the smallest interruption which can be detected at any
point in the field. Minimum object sensitivity describes the largest acceptable size of the interruption in the
sensing field. A minimum object sensitivity of one and one-fourth inches (31.75 mm) means that a one
and one-fourth inch (31.75 mm) diameter object will be continuously detected at all locations in the
sensing field.
In deriving the safety distance required in paragraph (h)(9)(v), all stopping time measurements should be
made with clutch/brake air pressure regulated to the press manufacturer's recommended value for full
clutch torque capability. The stopping time measurements should be made with the heaviest upper die
that is planned for use in the press. If the press has a slide counterbalance system, it is important that the
counterbalance be adjusted correctly for upper die weight according to the manufacturer's instructions.
While the brake monitor setting is based on the stopping time it actually measures, i.e., the normal
stopping time at the top of the stroke, it is important that the safety distance be computed from the longest
stopping time measured at any of the indicated three downstroke stopping positions listed in the
explanation of Ts. The use in the formula of twice the stopping time increase, Tm, allowed by the brake
monitor for brake wear allows for greater increases in the downstroke stopping time than occur in normal
stopping time at the top of the stroke.

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10. Inspection and Maintenance.[Reserved]
11. Safety System Certification/Validation
Mandatory requirements for certification/validation of the PSDI safety system are provided in appendix A
and appendix C to this standard. Nonmandatory supplementary information and guidelines relating to
certification/validation of the PSDI safety system are provided to appendix B to this standard.
[39 FR 32502, June 27, 1974, as amended at 39 FR 41846, Dec. 23, 1974; 40 FR 3982, Jan. 27, 1975; 43 FR 49750,
Oct. 24, 1978; 45 FR 8594, Feb. 8, 1980; 49 FR 18295, Apr. 30, 1984; 51 FR 34561, Sept. 29, 1986; 53 FR 8353,
8358 Mar. 14, 1988; 54 FR 24333, June 7, 1989; 61 FR 9240, Mar. 7, 1996; 69 FR 31882, June 8, 2004; 76 FR
80739, Dec. 27, 2011]

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