Fire Sprinkler Systems

OMB Control Number 3041-0029

Investigation Guideline
Fire Sprinkler Systems
Appendix 119
March 1999

Background Information
National fire loss data indicate that in 1996, there were an estimated 27,100 fires
attended by fire departments in structures where sprinkler systems were reported to be
installed. The fires occurred in locations such as public assembly (3,900), educational
(1,900), institutional (4,500), residential (11,000), and commercial (stores, offices)
structures (5,800). In 6,800 (25%) fires, the sprinkler system was reported to have
operated properly and in 1,500 (6%) the sprinklers was reported to have failed to
operate properly. In the remainder of the fires, the fire was insufficient to require the
sprinkler system to activate. These 27,100 fires were responsible for over 376 million
dollars in property damage.
Fire sprinklers are installed in many occupancies, and their presence in the residential
market is growing as local authorities are adopting sprinkler ordinances throughout the
United States. Some communities have required residential sprinkler systems by
passing ordinances or laws, while other communities have offered incentive programs
for installing sprinkler systems voluntarily. Recent Commission activities have raised
concern regarding the performance of fire sprinklers. A major concern is the failure of
sprinklers to operate under fire conditions. These failures are evident in the NFIRS fire
data. Data on fire sprinklers are being collected to identify potential causes of failures of
fire sprinklers and to develop recommendations for adoption in national fire codes and
state and local building codes.
The National Fire Protection Association reports that between 1987 and 1996, the
reduction of civilian deaths per thousand fires associated with automatic fire
suppression equipment is 65% for home, including single family homes, apartment
buildings, dormitories, and room/boarding houses and 83% for hotels and motels.
NFPA has no record of a fire that killed more than two people in a completely
sprinklered public assembly, educational, institutional, or residential structure where the
system was operating properly.
Types of Fire Sprinklers
There are several types of fire sprinkler systems where each depends on the nature of
the area being protected. The type of sprinkler system used in most residential
structures is the wet pipe system.

Wet Pipe Systems are the most common, economical and effective systems for most
locations. The piping contains water at all times to discharge as soon as a sprinkler is
activated. The disadvantage of wet pipe systems is that they can't be exposed to
freezing temperatures.
Dry Pipe Systems are used in parking garages, warehouses and other areas subject to
freezing. Instead of water, the systems keep piping filled with pressurized air, usually
supplied from an air compressor. The air holds the water back at a dry pipe valve. When
a sprinkler opens, the air rushes out, followed by the water. There's a brief delay in the
delivery of the water to the fire. To accommodate this, the designer must calculate the
area of sprinkler operation to be 30 percent larger than it actually is, with a
corresponding increase in water demand.
Preaction Systems use electronic heat or smoke detector operation to open a valve and
allow water into the piping system. Even then, water will not discharge until heat opens
a sprinkler. In large warehouses, these systems often are used instead of dry pipe
systems. In the case of an accident-- such as a fork lift breaking sprinkler piping-- a dry
pipe system could fill with water that could then freeze, causing severe damage.
Fire sprinklers are individually heat-activated by a fusible link or glass bulb and
connected to a network of piping with water under pressure. When the heat of a fire
causes the fusible link to melt or glass bulb to shatter in a sprinkler, that sprinkler head
essentially becomes an open faucet releasing water directly over the source of heat.
Sprinkler Systems Safety Standards / Product Listings
Most sprinkler systems are listed to UL199 (Automatic Sprinklers for Fire-Protections
Service) or UL1626 (Residential Sprinklers for Fire-Service Protection) and FM2000
(Automatic Sprinklers for Fire Protection).

Headquarters Contacts
Kimberly Ault, EHHA, 301-504-0470 x1269
Linda Smith, EHHA, 301-504-0470 x1275
Rikki Khanna, ESME, 301-504-0508 x1291

Investigation Instructions
These instructions pertain to all fire incidents where a sprinkler system was present,
whether it activated properly, failed to control the fire, or failed to activate. The targeted
cases are fires in public assembly, educational, residential, store, and office structures.
The attached data record sheet will ensure a uniform approach for gathering data about
these fire incidents.

Every completed field investigation should contain a completed data record sheet, in
addition to the CPSC standard 182 form and standard narrative description of the preincident, incident, and post-incident. Photographs of the sprinkler heads involved in the
incident should be included in the investigation along with a sample. A copy of the
attending fire department’s investigative report of the incident, a copy of the installation
drawings of the sprinkler system, and any reports regarding testing or repairing of the
sprinkler system should be obtained.

Free Text Summary
•

•
•
•
•
•

•
•

•
•

•

Describe the sequence of events that led to the incident. Describe incident,
including the type and age of structure where the fire occurred, the type of
sprinkler system, the make and model of the sprinkler system, the date of
manufacture of the sprinkler system, and whether the system was
disconnected or turned off during the incident.
In addition, describe the consumer product involved in fire, including
manufacturer and model number.
Describe any injuries and deaths involved in the incident and the nature of the
injuries.
Determine the date of installation of the system and who installed the
sprinkler system.
Determine the number of sprinkler heads in the room of fire origin and the
number that operated or failed to operate. Describe the location of the
sprinkler heads in relation to the fire origin.
Determine whether the structure was ever remodeled or enlarged and
whether the sprinkler system was extended to cover the enlarged area. If
more than one manufacturer (or model) or type of sprinkler, determine all
manufacturers and types.
Determine whether the sprinkler system was ever tested (frequency of
testing), serviced, or repaired and whether there were any prior incidents
involving the sprinkler system, such as leaking water incidents.
Determine whether the sprinkler system was subjected to freezing,
overheating, mechanical damage, or apparent corrosion. Determine whether
any of the sprinkler heads involved in the incident were ever painted over,
had objects hanging from the heads, or were obstructed in any way.
Determine the type of piping material (plastic, steel, copper) used in the
system and whether there was any prior water damage apparent on the
ceiling surrounding the sprinkler heads.
Determine the point of origin of the fire, what item first ignited and estimate
any property damage including flame spread damage (e.g., product, small
area surrounding product, room, floor, entire structure, etc.), water damage,
and property dollar loss.
Describe any safety certification labels, such as UL, CSA, ETL or other
certification, or conformance with specific standards.

•

For data retrieval from the computer, please use the following key words in
the free text summary as appropriate: fire sprinkler system.

Photographs of Incident Scene
•

Photos of the products involved and diagrams describing the location of the
incident should be included in the investigation report. If possible, please
include photographs of the fire scene on-site.

Sample Collection Instructions
•
•

•
•

If the fire incident involved sprinkler heads that failed to operate, collect five
(or as many as are available) separate sprinkler heads directly above the
fire's point of origin.
If the fire incident involved sprinkler heads that operated properly, then collect
five sprinkler heads (or as many as are available) from both directly above the
fire's point of origin and in the general area surrounding the fire's point of
origin.
Place sample in air tight plastic bag.
Send all samples to the sample custodian at CSPC warehouse and
notify Kim Ault in Directorate for Epidemiology and Heath Sciences at
301- 504-0470 x1269.

Instructions for Obtaining Documents
•
•
•
•

Determine whether the fire department attended the incident and obtain copy
of fire incident, casualty, and investigation reports.
Obtain copies of any official report if fire department did not attend (e.g. police
report, emergency response report, service/repair report, insurance report,
etc.)
Obtain the sprinkler system installation drawings from authority having
jurisdiction.
Obtain copies of any testing reports, repairs, service contracts, or upgrades to
sprinkler system.

The following page contains some pictures of fire sprinklers.

Wet Pipe Systems

Dry Pipe Systems

Investigation Guideline
Data Record Sheet for Sprinkler Systems
Task Number
Type of Structure
Public Assembly
Educational
Institutional
Residential
Store/Office
Other

Mark "Y" to one choice

Age of Structure (In Years)
Type of Sprinkler System
Wet Pipe System
Dry Pipe System
Preaction Systems
Unknown

Mark "Y" to one choice

Date System Installed
Installer of System
Date Sprinkler Manufactured
System Disconnected / Turned off at time of
incident

Yes

No

Unknown

Yes
Yes
Yes
Yes
Yes

No
No
No
No
No

Unknown
Unknown
Unknown
Unknown
Unknown

Number of Sprinkler Heads in Room of Origin
Number of Sprinkler Heads Operated
Number of Sprinkler Heads Failed
Sprinkler System Enlarged
Sprinkler System Tested
Sprinkler System Repaired
Sprinkler System Serviced
Prior Problems with System
If Prior Problems, Describe

Type of Piping Material or System
Plastic
Steel
Copper
Other
Unknown

Mark "Y" to one choice

Sprinklers System Exposure Conditions
Freezing
Overheating
Mechanical Damage
Corrosion
Painted
Objects Hanging from Head
Obstruction
Other

Mark "Y" to one choice

Point of Origin
Item First Ignited
Estimated Dollar Loss
Estimated Water Damage
Number of Injuries
Number of Deaths