Subpart L
This subpart covers requirements for fire brigades and all portable and fixed fire suppression equipment, fire detection systems, and fire or employee alarm systems installed to meet workplace fire protection needs. See the Scope in 1910.155(a) for the exact wording and to confirm which systems are included.
This subpart applies to all employments except maritime, construction, and agriculture. See the Application in 1910.155(b) for the exclusion list and to determine if your workplace is covered.
“Approved” means acceptable to the Assistant Secretary by one of several routes: acceptance/certification/listing/labeling by a nationally recognized testing laboratory (NRTL), inspection or testing by another Federal agency when no NRTL applies, or employer-kept test data for custom-made equipment. See Definition of Approved in 1910.155(c)(3) and the guidance about NRTLs at 1910.7.
The standard directs you to [1910.7] for the definition of a nationally recognized testing laboratory (NRTL). See 1910.155(c)(3)(iv)(E) and 1910.7 for the full NRTL criteria and program details.
An automatic fire detection device is a device designed to automatically detect the presence of fire by sensing heat, flame, light, smoke, or other products of combustion. See the definition in 1910.155(c)(5) to confirm that your detection equipment meets this basic description.
Class A fires involve ordinary combustibles (wood, paper, cloth); Class B fires involve flammable/combustible liquids, gases, greases; Class C fires involve energized electrical equipment where a nonconductive extinguishing agent is needed; Class D fires involve combustible metals like magnesium or sodium. See Class A–D definitions in 1910.155(c)(8)–(11).
An incipient stage fire is an initial or beginning stage fire that can be controlled or extinguished by portable fire extinguishers, a Class II standpipe, or small hose systems without the need for protective clothing or breathing apparatus. See the definition in 1910.155(c)(26) to understand when portable extinguishers are considered appropriate and when fires have progressed beyond the incipient stage.
A fire brigade is an organized group of employees who are trained and skilled in at least basic firefighting operations. Employers should consider forming a fire brigade when workplace hazards, response times, or facility layout justify an in-house trained team. See the definition in 1910.155(c)(18) and the broader Subpart L scope for related employer responsibilities.
A fixed extinguishing system is a permanently installed system that extinguishes or controls a fire at its location, while a local application system is a fixed system with agent supply and nozzles arranged to discharge directly on the burning material (targeted discharge). See fixed extinguishing system in 1910.155(c)(19) and local application system in 1910.155(c)(30).
A sprinkler alarm is an approved device that sounds when waterflow equals or exceeds that from a single automatic sprinkler; a sprinkler system is a piping system designed per fire protection engineering standards to control or extinguish fires, including water supply and sprinklers. See 1910.155(c)(37)–(38).
Class I standpipe systems provide 2½" connections for fire departments and trained personnel handling heavy streams; Class II are 1½" for employee use to control incipient fires; Class III combines both for use by trained employees and fire departments; a small hose system ranges from 5/8" up to 1½" for employees to fight incipient-stage fires. See the standpipe definitions in 1910.155(c)(39)(i)–(iv).
A total flooding system is a fixed suppression system arranged to automatically discharge a predetermined concentration of agent into an enclosed space to extinguish or control a fire (i.e., it floods the protected enclosure). It is used for enclosed hazards where agent concentration can be controlled and is defined at 1910.155(c)(40).
Inspection is a visual check to ensure fire protection systems and equipment are in place, charged, and ready; maintenance means performing services to ensure systems will perform as expected in a fire. See the definitions in 1910.155(c)(27) and (31). Employers should follow these definitions when setting inspection and maintenance schedules.
Custom-made equipment can be considered approved if it is designed and fabricated for use by its manufacturer on the basis of test data that the employer keeps and makes available to the Assistant Secretary for inspection. See 1910.155(c)(3)(iii) for the exact recordkeeping and availability expectation.
A pre-discharge employee alarm is an alarm that sounds at a set time before an extinguishing system discharges so employees can evacuate the discharge area prior to agent release. See the definition in 1910.155(c)(35) — it's required where automatic discharge could create a hazardous environment for employees during the discharge.
A positive-pressure breathing apparatus is self-contained breathing apparatus in which the pressure in the breathing zone is positive relative to the immediate environment during inhalation and exhalation. See the definition in 1910.155(c)(34) and plan breathing protection accordingly for interior structural firefighting and other hazardous atmospheres.
A gaseous agent is a fire extinguishing agent that is in the gaseous state at normal room temperature and pressure. See the definition in 1910.155(c)(22) when selecting suppression agents for enclosed hazards.
AFFF is a fluorinated surfactant with a foam stabilizer diluted with water to form a temporary film on some hydrocarbon fuel surfaces that suppresses vapor generation and extinguishes fires. See the AFFF definition in 1910.155(c)(2) for details when choosing foam systems for flammable liquid hazards.
The standard defines a helmet as a head protective device with a rigid shell, energy absorption system, and chin strap intended to protect against impact, electric shock, penetration, heat, and flame; it may include lining, storm flaps and pockets. See the helmet definition in 1910.155(c)(25) to guide selection of head protection for firefighting duties.