Investigation Guideline

Grass Trimmers and Edgers
Appendix No. 88

Investigation Guideline
Product:
Appendix #:
Date amended:

Grass (String) Trimmers and Edgers
88
July 2004

I. Introduction
NOTE: This guideline is to be used for string trimmers, edgers, and trimmer/brushcutters when the
trimmer/brushcutters are being used in the trimmer mode. If the trimmer/brushcutter is being used in
the brushcutter mode, see Investigation Guideline - Appendix No. 89, “Brushcutters”.

A. Background Information
String trimmers and edgers were associated with an estimated 12,500 emergency room
treated injuries in 2002.
The major hazard patterns for string trimmers are thrown objects and non- metallic string
contact. The major hazard patterns for edgers are thrown objects and metallic cutting blade
contact. Other hazard patterns include straining/spraining and tripping/slipping. In some
cases electric shock and fire can also result from use of string trimmers and edgers.
Based on the special study of string trimmers, edgers, and brushcutters related to incidents
between May 1, 2002 and August 1, 2002, the main body part injured was the eyeball,
followed by the extremities (i.e., lower leg, finger, foot). The primary diagnoses for injuries
to operators were contusions/abrasions and lacerations.
Investigations are needed to determine the effectiveness of the voluntary American National
Standard (ANSI-B175.3) for Grass Trimmers and Brushcutters. The purpose is to reduce the
hazards, especially thrown objects, associated with the use of string trimmers, edgers and
brushcutters.

B. Product Description
Grass (string) trimmers hand- held devices that use a nylon string at the end of a 4 – 5 foot
shaft to cut grass and weeds in the areas where lawn mowers cannot generally reach. They
may be gasoline or electrically powered (See Figures 1, 2, and 3). Trimmers may have a
plastic blade or may use a monofilament line or string. The blades or filament are mounted
so that they rotate in the horizontal plane powered by a small 1 or 2 horsepower engine. The
spinning action of the monofilament string or line cuts the grass or weeds at the level at

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which the operator holds the device. Trimmer blades or the monofilament line usually do
not penetrate the turf.
Lawn edgers are wheeled devices that utilize a metallic blade designed to rotate in the
vertical plane and cut an edge or groove between the turf and other surfaces (Figure 4 and
5). They are used for edging walkways, garden beds, and driveways. They may be gasoline
or electrically powered. These tools have wheels and a long handle. Note that the blade of
the unit can be rotated to operate in the horizontal plane so that the product may be used as a
trimmer. Some models allow the blade cutter to be replaced by a nylon string.
Trimmer-brushcutters are gasoline-powered and may be equipped with a monofilament line
for cutting grass and weeds, or with rigid metal or plastic blades for cutting brush or thin
saplings (Figure 6). This guideline pertains to brushcutters being used in the trimmer mode,
equipped with a monofilament line (or string).

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Figure 1. Gas (25 cc engine) Grass (String) Trimmer

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Figure 2. Electric Grass (String) Trimmer - Corded

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Figure 3. Electric Grass (String) Trimmer - Cordless

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Figure 4. Edger – Gas

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Figure 5. Edger – Electric

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Figure 6. Gas Brushcutter

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C. Specific Items of Interest
•

Of particular interest are details about the shield around the blade assembly.
Indicate the position of the shield relative to the operator of the blade, the size of the
shield and whether the shield was on the trimmer at the time of the incident.

•

Specify the type of vegetation being cut at the time of the incident.

•

Obtain product safety instructions, if available, and describe the information included
on product labels: list warnings, date codes, product certificatio n, ratings.

•

Details on cutting attachment are important. Features like dimensions, material (i.e.
nylon string, metal or plastic), number of teeth, and manufacturer.

D. Headquarters Contacts
Natalie Marcy
John Murphy

EPHA (301) 504-7329
ESME (301) 504-7541

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II. Instructions for Collecting Specific Information
A. Free Text Summary
•

It is important to describe clearly the sequence of events. Describe what happened
immediately before, during, and after the incident. Include location of the victim
relative to the grass trimmer, and a detailed description of the parts of the grass
trimmer involved in the injury.

•

Describe the nature of the injuries (did they result from a rotating blade, or
filament/string, thrown object, electric shock, snagging of clothing on the machine, or
failure of the product).

•

Describe whether the victim is the operator or bystander. Where the incident occurred
(home, school, work, etc.).

B. Description of Incident Environment
•

Outline the general conditions (i.e., sunny, cloudy, any adverse weather conditions,
temperature, wind speed and direction, rain, snow, etc).

•

Lighting conditions at the time of the accident.

•

Size of the area being cut and type of material being cut.

•

Condition of the material surface being cut and vegetation density (i.e., wet, dry,
thick, long, etc.). Include the height of the grass or brush being trimmed.

•

Ground surface conditions (wet, uneven, rough, slippery, etc.) and slope of terrain.

•

Preparation of area being cut (e.g., removing objects that could be thrown by the
trimmer or edgers.

C. Description of Victim
1. Indicate victim's age, sex, height, weight and whether the victim was the operator, an
assistant, or a bystander.
2. Indicate if operator was tired, rested, distracted, etc. at the time of the incident.
3. Indicate any medication or alcohol consumed by the operator and whether the
operator had any physical or competence reducing handicaps or disabilities.

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4. Provide a complete description of clothing and safety equipment used by the operator
(e.g., gloves, safety shoes, goggles, hard hat, hearing protection).
5. Determine operator's awareness of possible dangers in the cutting activity and any
precautions taken to prevent accidents.
6. Describe the accident sequence in detail, indicating the body part injured, the nature
of the injury and its severity.
7. Indicate:
(a) The victim's knowledge of operating instructions - whether self-taught (by
owner's manual) or by an instructor.
(b) Previous experience in operating, repair, or adjustment of the trimmer or edger.
(c) Previous injuries in using trimmer or edger.
(d) Position of operator's hands and feet relative to the trimmer or edger.
(e) Operator's awareness of the victim's presence.
(f) Victim's awareness of operator's presence.
(g) Victim's location in relation to trimming operation.

D. Description of Interaction between Injured Person(s) and Product
•

Indicate the degree of user familiarity with product operation, repair, and adjustment.

•

For accidents involving contact with a blade or monofilament (string), describe the part
of the body injured and how it contacted the blade or filament. Indicate the manner in
which product shielding may have been a factor in the accident.

•

For accidents involving thrown objects, describe: the object and how it came into
contact with the trimmer or edger (whether it ricocheted off another object or came
directly off the cutting head); how high and far the object was thrown; how far the
victim was standing from the machine, and where the victim was struck.

•

For accidents involving electric shock, indicate: the location on the machine or cord
where current was transmitted to the victim, the prevailing weather, dampness of the
terrain, and the victim's activity. Indicate how the shock occurred (e.g., electric cord
cut; contact with power lines; shock through the handle).

•

For accidents involving fires, indicate: the sequence of events, the source of fuel and the
manner of ignition.

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E. Description of Product (Involved in the injury)
Safety Warning: When examining a gasoline powered edger or trimmer,
remove the spark plug wire from the spark plug and
ground it to the chassis before manual inspection. The
act of rotating the blade by hand may cause the engine
to start if this is not done. Electrical units should be
unplugged before examination.
Provide the following detailed information on the string trimmer:
•

Describe the type of machine (trimmer, edger or combination). Indicate the
manufacturer, brand, model name and/or number and serial number. Indicate age and
whether purchased new/used or rented.
(a) If gasoline powered, indicate the following:
(1) Horsepower rating, cubic inch displacement
(2) Capacity of fuel tank.
(3) Location of fuel tank.
(4) Leakage in fuel tank, fuel liner, etc., if any.
(b) If electric powered, indicate the following:
(1) Power cord and gauge (if available)
- Length
- Covering (jacketed or parallel conductor construction) and
indicate any damage to insulation or conductors
- If extension cord involved, provide some information requested
above for the extension cord.
(2) Battery
- cord amperage
- voltage
- if recharging involved in the incident, provide description of the
recharger.

•

Describe the power source receptacle, its location (indoor, outdoor), and any circuit
protection and amperage (fuse, circuit breaker, ground fault interrupter).

•

Describe if the unit has been modified or changed. Ask who made the modifications or
changes.

•

Electric appliance parts description
- Switch (on/off, lock "on" feature, speed control).
- Motor
- Open (wiring, brushes, windings visible)
- Enclosed

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•

The blade or filament
(1) Type of blade or filament (material , design)
(2) Type of cutting edge (e.g. smooth, serrated)
(3) Dimensions (length, width, thickness)
(4) Clearance between blade tip and housing

•

Determine if the cutting head was provided by the manufacturer of the trimmer. If not,
what company manufactured the cutting head?

•
•

Machine adjustment
(1) Method of adjustment
(2) Number of positions

•

Describe the machine shielding including deflectors

•

If the device has wheels, describe the wheel construction
(1) Material (plastic, steel, etc.)
(2) Tires (material, tread width, diameter).

•

Indicate the type of handle (Bar, T-style, wheel) and the presence of handgrips.

•

Weight and length of trimmer or edger

•

Certification labels (OPEI, UL, ANSI)

•

Modifications made to the trimmer or edger, if any.

III. Photographs/ Diagrams of Incident Scene
•
•
•
•
•

Take a series of good, clear photographs of the incident scene and the product,
simulating the incident sequence.
Photograph the unit (front, side, rear), the manufacturers’ name plate, OPEI
certification, UL listings, warning signs, and saefty features such as shielding.
Provide close-up photos of labels, controls, safety devices or guards, and off-on
switches.
Have victim pose for photo that depicts his/her position in relation to the trimmer
at the time of the incident (with power to the unit “off”).
Lay out, in diagram form, the distances between the operator, any objects with
which the trimmer or edger made contact, and the victim (if not the operator).

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IV. Obtaining samples and documents related to the investigation
• Photocopy the owners’ manual and attach it to the report.
• Collect any official records associated with this incident that may be available.
• Document the victim's contacts with the retailer and manufacturer regarding the
incident and obtain copies of all correspondence.

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DATA RECORD SHEET
for String Trimmers and Edgers
1.

Task Number ____________________________

2.

Incident Date (MM/DD/YYYY) ______________

3.

What type of product was involved in the accident?
_____ Grass trimmer
_____ Edger

DESCRIPTION OF INCIDENT ENVIRONMENT
4.

Describe the general weather conditions at the time of the incident.

5.

What were you (was the operator) trimming at the time of the accident?
(Select as many as applicable)
_____
_____
_____
_____
_____

Grass
Weed
Brush
Small tree
Other (Specified: ______________________________)

6.

What was the condition of the material surface being cut and vegetation density (i.e.,
wet, dry, thick, long)?

7.

Describe whether there were any environmental conditions such as wet grass,
uneven surfaces (holes, bumps, rocks, or obstacles), a steep embankment or anything
else that may have contributed to the incident?

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8.

Were objects that could be thrown by the trimmer or edgers removed from the area
to be cut prior to using the trimmer or edger?

DESCRIPTION OF VICTIM
9.
Was the victim/injured person an operator or bystander?
_____ Operator
_____ Bystander
_____ Helper

10.

Indicate the victim’s age, sex, height, and weight.
_____ Age
_____ Sex
_____ Height
_____ Weight

11.

Indicate the operator’s level of alertness at the time of the injury (i.e., tired, rested,
distracted, etc).

12.

Determine whether the operator was ill or under any medication, drug, or alcohol at
the time of the accident?
_____ Yes à (Specify:____________________________________)
_____ No

13.

Was the operator wearing protective gear at the time of the accident?
(Select as many as applicable)
_____ Eyeglasses
_____ Safety goggles

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_____ Gloves
_____ Steel toe shoes
_____ Heavy pants
_____ Other special clothing (Specify:________________________)

PRODUCT SHIELDING
14.
Was the shield attached to the trimmer or brushcutter at the time of the accident?

_____ Yes
_____ No
15.

If the shield was attached to the trimmer, ask whether it was damaged, broken, or in
good condition?
_____ Damaged
_____ Broken
_____ In good condition

16.

If the shield was NOT attached, ask why it was not attached?
_____ Had broken off
_____ Had been removed
_____ Never had one
_____ Other (Specify:___________________________)

FOR INCIDENTS INVOLVING THROWN OBJECTS:
17.
Describe the thrown object and how it came into contact with the trimmer or edger.

18.

Determine whether the object ricocheted off another object or was it thrown directly
(in a straight line) from the cutting head?
_____ Ricochet off another object
_____ Directly from the cutting head

19.

Indicate whether the thrown object was a part of the machine or was it a piece of
grass, twig, pebble, etc?

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_____ A part of the machine (Specify:_________________________)
_____ A piece of grass, twig, or pebble, etc.
_____ Other (Specify:_____________________________)

20.

How high and far was the object thrown?

21.

How far away from the machine was the victim standing?

22.

Where was the victim struck?

FOR INCIDENT INVOLVING ELECTRIC SHOCK,
23.
Indicate the location of the machine or cord where the current was transmitted to the
victim.

24.

What was the prevailing weather at the time of the incident? Was the terrain damp?

25.

Indicate how the shock occurred (i.e., was the electric cord cut, was there contact
with the power lines, shock through handle)?

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FOR INCIDENTS INVOLVING FIRE,
26.
Indicate the sequence of events, source of the fuel and the manner of ignition.

DESCRIPTION OF PRODUCT
27.
Was the trimmer or edger involved in the incident gas or electric?
_____ Gas (What was the engine size? ______ )
_____ Electric (Was the product corded or did it use a battery?)
_____ Corded (Please describe the type, length, and gauge of
the cord and extension cord. ____________).
____ Battery (Describe voltage, if recharging involved,
describe the recharger).
28.

Describe the power source receptacle, its location (indoor, outdoor), and any circuit
protection and amperage (fuse, circuit breaker, ground fault interrupter).

29.

Was the cutting head produced by the manufacturer of the trimmer or was it
produced by someone other than the manufacturer?
_______ Manufacturer of trimmer
_______ Other

30.

About how old is the trimmer or brushcutter?
(Write down the number of years, months, or days)
____ Years
____ Months
____ Days
____ Don't know

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31.

What is the brand name (manufacturer) and model name/number of the trimmer or
edger?
Mfr. ________________________________
Model # _____________________________
Serial # _____________________________
Horsepower/Displacement __________________________
Don't know _________________

32.

Had the trimmer or edger been changed or modified in any way since you got it?
_____ Yes
_____ No

33.

If changed or modified, ASK:
• How was the trimmer or brushcutter changed or modified?
______________________________________________
•

Who did the modifications?
_____ Victim
_____ Friend
_____ Relative
_____ Other (Specify:_______________________)

34.

Was the motor/engine running at the time of the accident? (Determine if the trimmer
or edger had just been turned “on” or “off”).
_____
_____
_____
_____

35.

Motor/engine was running.
Motor/engine was not running.
Motor/engine was just turned “on”.
Motor/engine was just turned “off”.

What type of cutting head was being used at the time of the accident and what is the
manufacturer of the cutting head?
_____ Non-metallic string
_____ Non-metallic head
_____ Metallic cutting blade
_____ Other (Specify: ______________________________________)

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36.

Determine how long the operator had been working with the trimmer or brushcutter
that day before the accident occurred? (Write down the number of hours and/or
minutes)
_____ Hours _____ Minutes

37.

Determine how often and for what length of time the operator used the trimmer or
edger?

38.

Determine if the operator remembers any warnings or safety precautions about the
operation of the trimmer or brushcutter that were printed in the owner’s manual?

39.

Describe whether the operator remembers seeing any warnings or safety precautions
printed on a label on the trimmer or brushcutter?

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