OSHA general industry fire protection study guide
Subpart L of OSHA's general industry rules (29 CFR 1910.155 to 1910.165) covers fire protection. It applies to all employments except maritime, construction and agriculture. This guide sets out what the rule text states on its scope and definitions, portable fire extinguishers (placement, inspection, maintenance, hydrostatic testing, and employee education and training), basic standpipe and sprinkler requirements, fire detection systems and employee alarm systems. Fire brigades (1910.156) are not covered. Codes the rule names (such as NFPA fire codes) are only named, not summarized. Every point links to the regulation and quotes its exact words.
Scope and definitions
Subpart L contains requirements for fire brigades and for all portable and fixed fire suppression equipment, fire detection systems, and fire or employee alarm systems installed to meet the fire protection requirements of Part 1910.
“This subpart contains requirements for fire brigades, and all portable and fixed fire suppression equipment, fire detection systems, and fire or employee alarm systems installed to meet the fire protection requirements of 29 CFR part 1910.”
29 CFR 1910.155, Scope, application and definitions applicable to this subpart
Subpart L applies to all employments except maritime, construction and agriculture.
“This subpart applies to all employments except for maritime, construction, and agriculture.”
29 CFR 1910.155, Scope, application and definitions applicable to this subpart
A Class A fire involves ordinary combustible materials such as paper, wood, cloth, and some rubber and plastic materials.
“Class A fire means a fire involving ordinary combustible materials such as paper, wood, cloth, and some rubber and plastic materials.”
29 CFR 1910.155, Scope, application and definitions applicable to this subpart
A Class B fire involves flammable or combustible liquids, flammable gases, greases and similar materials, and some rubber and plastic materials.
“Class B fire means a fire involving flammable or combustible liquids, flammable gases, greases and similar materials, and some rubber and plastic materials.”
29 CFR 1910.155, Scope, application and definitions applicable to this subpart
A Class C fire involves energized electrical equipment where safety to the employee requires electrically nonconductive extinguishing media.
“Class C fire means a fire involving energized electrical equipment where safety to the employee requires the use of electrically nonconductive extinguishing media.”
29 CFR 1910.155, Scope, application and definitions applicable to this subpart
A Class D fire involves combustible metals such as magnesium, titanium, zirconium, sodium, lithium and potassium.
“Class D fire means a fire involving combustible metals such as magnesium, titanium, zirconium, sodium, lithium and potassium.”
29 CFR 1910.155, Scope, application and definitions applicable to this subpart
An incipient stage fire is one in its initial or beginning stage that can be controlled or extinguished by portable fire extinguishers, Class II standpipe or small hose systems without the need for protective clothing or breathing apparatus.
“Incipient stage fire means a fire which is in the initial or beginning stage and which can be controlled or extinguished by portable fire extinguishers, Class II standpipe or small hose systems without the need for protective clothing or breathing apparatus.”
29 CFR 1910.155, Scope, application and definitions applicable to this subpart
Inspection is a visual check of fire protection systems and equipment to ensure they are in place, charged and ready for use in the event of a fire.
“Inspection means a visual check of fire protection systems and equipment to ensure that they are in place, charged, and ready for use in the event of a fire.”
29 CFR 1910.155, Scope, application and definitions applicable to this subpart
Maintenance is the performance of services on fire protection equipment and systems so they will perform as expected in a fire. It differs from inspection because it requires checking internal fittings, devices and agent supplies.
“Maintenance means the performance of services on fire protection equipment and systems to assure that they will perform as expected in the event of a fire. Maintenance differs from inspection in that maintenance requires the checking of internal fittings, devices and agent supplies.”
29 CFR 1910.155, Scope, application and definitions applicable to this subpart
Not covered here
Fire brigades (1910.156) and the definitions used mainly for fire brigade equipment (such as protective clothing and breathing apparatus terms). We only write what an official source states, so study these parts with your certifying program's materials.
Extinguisher general rules
1910.157 applies to the placement, use, maintenance and testing of portable fire extinguishers provided for the use of employees.
“The requirements of this section apply to the placement, use, maintenance, and testing of portable fire extinguishers provided for the use of employees.”
The selection and distribution rules in paragraph (d) do not apply to extinguishers provided for employee use on the outside of workplace buildings or structures.
“Paragraph (d) of this section does not apply to extinguishers provided for employee use on the outside of workplace buildings or structures.”
Where extinguishers are provided but are not intended for employee use, and the employer has an emergency action plan and a fire prevention plan meeting 1910.38 and 1910.39, only paragraphs (e) and (f) of 1910.157 apply.
“Where extinguishers are provided but are not intended for employee use and the employer has an emergency action plan and a fire prevention plan that meet the requirements of 29 CFR 1910.38 and 29 CFR 1910.39 respectively, then only the requirements of paragraphs (e) and (f) of this section apply.”
An employer that has established and implemented a written fire safety policy requiring the immediate and total evacuation of employees when a fire alarm sounds, which includes an emergency action plan and a fire prevention plan meeting 1910.38 and 1910.39, and with no extinguishers available in the workplace, is exempt from all of 1910.157 unless a specific Part 1910 standard requires a portable fire extinguisher.
“Where the employer has established and implemented a written fire safety policy which requires the immediate and total evacuation of employees from the workplace upon the sounding of a fire alarm signal and which includes an emergency action plan and a fire prevention plan which meet the requirements of 29 CFR 1910.38 and 29 CFR 1910.39 respectively, and when extinguishers are not available in the workplace, the employer is exempt from all requirements of this section unless a specific standard in part 1910 requires that a portable fire extinguisher be provided.”
Where an emergency action plan meeting 1910.38 designates certain employees as the only ones authorized to use the available portable fire extinguishers, and requires all other employees in the fire area to immediately evacuate the affected work area when the fire alarm sounds, the employer is exempt from the distribution requirements in paragraph (d).
“Where the employer has an emergency action plan meeting the requirements of § 1910.38 which designates certain employees to be the only employees authorized to use the available portable fire extinguishers, and which requires all other employees in the fire area to immediately evacuate the affected work area upon the sounding of the fire alarm, the employer is exempt from the distribution requirements in paragraph (d) of this section.”
The employer must provide portable fire extinguishers and mount, locate and identify them so they are readily accessible to employees without subjecting employees to possible injury. Only approved portable fire extinguishers may be used to meet 1910.157.
“The employer shall provide portable fire extinguishers and shall mount, locate and identify them so that they are readily accessible to employees without subjecting the employees to possible injury. (2) Only approved portable fire extinguishers shall be used to meet the requirements of this section.”
The employer may not provide or make available in the workplace portable fire extinguishers using carbon tetrachloride or chlorobromomethane extinguishing agents.
“The employer shall not provide or make available in the workplace portable fire extinguishers using carbon tetrachloride or chlorobromomethane extinguishing agents.”
Portable fire extinguishers must be maintained fully charged and operable and kept in their designated places at all times except during use.
“The employer shall assure that portable fire extinguishers are maintained in a fully charged and operable condition and kept in their designated places at all times except during use.”
Selection and distribution
Portable fire extinguishers must be provided for employee use and selected and distributed based on the classes of anticipated workplace fires and on the size and degree of hazard which would affect their use.
“Portable fire extinguishers shall be provided for employee use and selected and distributed based on the classes of anticipated workplace fires and on the size and degree of hazard which would affect their use.”
Extinguishers for employee use on Class A fires must be distributed so the travel distance for employees to any extinguisher is 75 feet (22.9 m) or less.
“The employer shall distribute portable fire extinguishers for use by employees on Class A fires so that the travel distance for employees to any extinguisher is 75 feet (22.9 m) or less.”
Instead of Class A portable extinguishers, the employer may use uniformly spaced standpipe systems or hose stations connected to a sprinkler system installed for emergency use by employees, provided they meet 1910.158 or 1910.159, provide total coverage of the area to be protected, and employees are trained at least annually in their use.
“The employer may use uniformly spaced standpipe systems or hose stations connected to a sprinkler system installed for emergency use by employees instead of Class A portable fire extinguishers, provided that such systems meet the respective requirements of § 1910.158 or § 1910.159, that they provide total coverage of the area to be protected, and that employees are trained at least annually in their use.”
Extinguishers for employee use on Class B fires must be distributed so the travel distance from the Class B hazard area to any extinguisher is 50 feet (15.2 m) or less.
“The employer shall distribute portable fire extinguishers for use by employees on Class B fires so that the travel distance from the Class B hazard area to any extinguisher is 50 feet (15.2 m) or less.”
Extinguishers used for Class C hazards are distributed on the basis of the appropriate pattern for the existing Class A or Class B hazards.
“The employer shall distribute portable fire extinguishers used for Class C hazards on the basis of the appropriate pattern for the existing Class A or Class B hazards.”
Portable fire extinguishers or other containers of Class D extinguishing agent for use by employees must be distributed so the travel distance from the combustible metal working area to any extinguishing agent is 75 feet (22.9 m) or less. Class D extinguishers are required in combustible metal working areas where combustible metal powders, flakes, shavings or similarly sized products are generated at least once every two weeks.
“The employer shall distribute portable fire extinguishers or other containers of Class D extinguishing agent for use by employees so that the travel distance from the combustible metal working area to any extinguishing agent is 75 feet (22.9 m) or less. Portable fire extinguishers for Class D hazards are required in those combustible metal working areas where combustible metal powders, flakes, shavings, or similarly sized products are generated at least once every two weeks.”
Inspection and maintenance
The employer is responsible for the inspection, maintenance and testing of all portable fire extinguishers in the workplace.
“The employer shall be responsible for the inspection, maintenance and testing of all portable fire extinguishers in the workplace.”
Portable extinguishers, or hose used in lieu of them under paragraph (d)(3), must be visually inspected monthly.
“Portable extinguishers or hose used in lieu thereof under paragraph (d)(3) of this section shall be visually inspected monthly.”
Portable fire extinguishers must get an annual maintenance check. Stored pressure extinguishers do not require an internal examination.
“The employer shall assure that portable fire extinguishers are subjected to an annual maintenance check. Stored pressure extinguishers do not require an internal examination.”
The employer must record the annual maintenance date and keep the record for one year after the last entry or the life of the shell, whichever is less, and make it available to the Assistant Secretary on request.
“The employer shall record the annual maintenance date and retain this record for one year after the last entry or the life of the shell, whichever is less. The record shall be available to the Assistant Secretary upon request.”
Stored pressure dry chemical extinguishers that require a 12-year hydrostatic test must be emptied and given applicable maintenance every 6 years. Dry chemical extinguishers with non-refillable disposable containers are exempt, and the 6 years start again from the date of any recharging or hydrostatic testing.
“The employer shall assure that stored pressure dry chemical extinguishers that require a 12-year hydrostatic test are emptied and subjected to applicable maintenance procedures every 6 years. Dry chemical extinguishers having non-refillable disposable containers are exempt from this requirement. When recharging or hydrostatic testing is performed, the 6-year requirement begins from that date.”
Alternate equivalent protection must be provided when portable fire extinguishers are removed from service for maintenance and recharging.
“The employer shall assure that alternate equivalent protection is provided when portable fire extinguishers are removed from service for maintenance and recharging.”
Hydrostatic testing
Hydrostatic testing must be performed by trained persons with suitable testing equipment and facilities.
“The employer shall assure that hydrostatic testing is performed by trained persons with suitable testing equipment and facilities.”
Portable extinguishers must be hydrostatically tested at the intervals listed in Table L-1 of 1910.157, except under any of the conditions listed in 1910.157(f)(2)(i) to (v).
“The employer shall assure that portable extinguishers are hydrostatically tested at the intervals listed in Table L-1 of this section, except under any of the following conditions:”
Those conditions are: the unit has been repaired by soldering, welding, brazing or use of patching compounds; the cylinder or shell threads are damaged; there is corrosion that has caused pitting, including corrosion under removable name plate assemblies; the extinguisher has been burned in a fire; or a calcium chloride extinguishing agent has been used in a stainless steel shell.
“(i) When the unit has been repaired by soldering, welding, brazing, or use of patching compounds; (ii) When the cylinder or shell threads are damaged; (iii) When there is corrosion that has caused pitting, including corrosion under removable name plate assemblies; (iv) When the extinguisher has been burned in a fire; or (v) When a calcium chloride extinguishing agent has been used in a stainless steel shell.”
Table L-1 lists a 12-year test interval for dry chemical, stored pressure extinguishers with mild steel, brazed brass or aluminum shells.
“Dry chemical, stored pressure, with mild steel, brazed brass or aluminum shells 12”
Carbon dioxide extinguishers, and nitrogen or carbon dioxide cylinders used with wheeled extinguishers, must be tested every 5 years at 5/3 of the service pressure stamped into the cylinder. Nitrogen cylinders that comply with 49 CFR 173.34(e)(15) may be tested every 10 years.
“The employer shall assure that carbon dioxide extinguishers and nitrogen or carbon dioxide cylinders used with wheeled extinguishers are tested every 5 years at 5/3 of the service pressure as stamped into the cylinder. Nitrogen cylinders which comply with 49 CFR 173.34(e)(15) may be hydrostatically tested every 10 years.”
Carbon dioxide hose assemblies with a shut-off nozzle are hydrostatically tested at 1,250 psi (8,620 kPa); dry chemical and dry powder hose assemblies with a shut-off nozzle at 300 psi (2,070 kPa).
“The employer shall assure that carbon dioxide hose assemblies with a shut-off nozzle are hydrostatically tested at 1,250 psi (8,620 kPa). (7) The employer shall assure that dry chemical and dry powder hose assemblies with a shut-off nozzle are hydrostatically tested at 300 psi (2,070 kPa).”
Air or gas pressure may not be used for hydrostatic testing. Shells, cylinders or cartridges that fail a hydrostatic test, or are not fit for testing, must be removed from service and from the workplace.
“Air or gas pressure may not be used for hydrostatic testing. (14) Extinguisher shells, cylinders, or cartridges which fail a hydrostatic pressure test, or which are not fit for testing shall be removed from service and from the workplace.”
Evidence of required hydrostatic testing is a certification record with the test date, the signature of the person who performed the test, and the extinguisher's serial number or other identifier. It is kept until the extinguisher is retested at the Table L-1 interval or taken out of service, whichever comes first.
“Such evidence shall be in the form of a certification record which includes the date of the test, the signature of the person who performed the test and the serial number, or other identifier, of the fire extinguisher that was tested. Such records shall be kept until the extinguisher is hydrostatically retested at the time interval specified in Table L-1 or until the extinguisher is taken out of service, whichever comes first.”
Training and education
In Subpart L, education means imparting knowledge or skill through systematic instruction; it does not require formal classroom instruction.
“Education means the process of imparting knowledge or skill through systematic instruction. It does not require formal classroom instruction.”
29 CFR 1910.155, Scope, application and definitions applicable to this subpart
Training means making proficient through instruction and hands-on practice in the operation of equipment that is expected to be used and in the performance of assigned duties.
“Training means the process of making proficient through instruction and hands-on practice in the operation of equipment, including respiratory protection equipment, that is expected to be used and in the performance of assigned duties.”
29 CFR 1910.155, Scope, application and definitions applicable to this subpart
Where the employer has provided portable fire extinguishers for employee use, it must also provide an educational program to familiarize employees with the general principles of extinguisher use and the hazards of incipient stage fire fighting.
“Where the employer has provided portable fire extinguishers for employee use in the workplace, the employer shall also provide an educational program to familiarize employees with the general principles of fire extinguisher use and the hazards involved with incipient stage fire fighting.”
That education must be provided upon initial employment and at least annually thereafter.
“The employer shall provide the education required in paragraph (g)(1) of this section upon initial employment and at least annually thereafter.”
Employees designated to use fire fighting equipment as part of an emergency action plan must be trained in the use of the appropriate equipment, upon initial assignment to the designated group and at least annually thereafter.
“The employer shall provide employees who have been designated to use fire fighting equipment as part of an emergency action plan with training in the use of the appropriate equipment. (4) The employer shall provide the training required in paragraph (g)(3) of this section upon initial assignment to the designated group of employees and at least annually thereafter.”
Standpipe and sprinkler systems
1910.158 applies to all small hose, Class II and Class III standpipe systems installed to meet the requirements of a particular OSHA standard. It does not apply to Class I standpipe systems.
“This section applies to all small hose, Class II, and Class III standpipe systems installed to meet the requirements of a particular OSHA standard. (2) Exception. This section does not apply to Class I standpipe systems.”
The minimum water supply for standpipe and hose systems provided for the use of employees must be enough to provide 100 gallons per minute (6.3 l/s) for at least thirty minutes.
“The minimum water supply for standpipe and hose systems, which are provided for the use of employees, shall be sufficient to provide 100 gallons per minute (6.3 l/s) for a period of at least thirty minutes.”
Hose systems must be inspected at least annually and after each use to assure all equipment and hose are in place, available for use and in serviceable condition.
“The employer shall assure that hose systems are inspected at least annually and after each use to assure that all of the equipment and hose are in place, available for use, and in serviceable condition.”
Automatic sprinkler systems installed in workplaces but not required by OSHA are exempt from the requirements of 1910.159.
“Automatic sprinkler systems installed in workplaces, but not required by OSHA, are exempt from the requirements of this section.”
The employer must properly maintain an automatic sprinkler system installed to comply with 1910.159. A main drain flow test is performed on each system annually, and the inspector's test valve is opened at least every two years.
“The employer shall properly maintain an automatic sprinkler system installed to comply with this section. The employer shall assure that a main drain flow test is performed on each system annually. The inspector's test valve shall be opened at least every two years to assure that the sprinkler system operates properly.”
Not covered here
Fixed extinguishing systems (1910.160 to 1910.163), standpipe acceptance tests and hose details, and sprinkler design and spacing beyond the points above. We only write what an official source states, so study these parts with your certifying program's materials.
Fire detection and employee alarms
1910.164 applies to all automatic fire detection systems installed to meet the requirements of a particular OSHA standard.
“This section applies to all automatic fire detection systems installed to meet the requirements of a particular OSHA standard.”
Servicing, maintenance and testing of fire detection systems, including cleaning and necessary sensitivity adjustments, must be performed by a trained person knowledgeable in the operations and functions of the system.
“The employer shall assure that the servicing, maintenance and testing of fire detection systems, including cleaning and necessary sensitivity adjustments are performed by a trained person knowledgeable in the operations and functions of the system.”
Alarms or devices initiated by fire detector actuation may not be delayed more than 30 seconds unless the delay is necessary for the immediate safety of employees; such a delay must be addressed in an emergency action plan meeting 1910.38.
“The employer shall not delay alarms or devices initiated by fire detector actuation for more than 30 seconds unless such delay is necessary for the immediate safety of employees. When such delay is necessary, it shall be addressed in an emergency action plan meeting the requirements of § 1910.38.”
1910.165 applies to all emergency employee alarms installed to meet a particular OSHA standard. It does not apply to discharge or supervisory alarms required on fixed extinguishing systems, or to supervisory alarms on fire suppression, alarm or detection systems, unless they are intended to be employee alarm systems.
“This section applies to all emergency employee alarms installed to meet a particular OSHA standard. This section does not apply to those discharge or supervisory alarms required on various fixed extinguishing systems or to supervisory alarms on fire suppression, alarm or detection systems unless they are intended to be employee alarm systems.”
The employee alarm must be capable of being perceived above ambient noise or light levels by all employees in the affected portions of the workplace. Tactile devices may be used for employees who would not otherwise recognize the audible or visual alarm.
“The employee alarm shall be capable of being perceived above ambient noise or light levels by all employees in the affected portions of the workplace. Tactile devices may be used to alert those employees who would not otherwise be able to recognize the audible or visual alarm.”
The alarm must be distinctive and recognizable as a signal to evacuate the work area or to perform actions designated under the emergency action plan.
“The employee alarm shall be distinctive and recognizable as a signal to evacuate the work area or to perform actions designated under the emergency action plan.”
Employers with 10 or fewer employees in a particular workplace may use direct voice communication to sound the alarm, provided all employees can hear it; such workplaces need not have a back-up system.
“For those employers with 10 or fewer employees in a particular workplace, direct voice communication is an acceptable procedure for sounding the alarm provided all employees can hear the alarm. Such workplaces need not have a back-up system.”
A test of the reliability and adequacy of non-supervised employee alarm systems is made every two months. In a multi-actuation device system, a different actuation device is used in each test so that no device is used for two consecutive tests.
“The employer shall assure that a test of the reliability and adequacy of non-supervised employee alarm systems is made every two months. A different actuation device shall be used in each test of a multi-actuation device system so that no individual device is used for two consecutive tests.”
Not covered here
The appendices to Subpart L. Except Appendix E (test methods for fire brigade protective clothing), they serve as nonmandatory guidelines. We only write what an official source states, so study these parts with your certifying program's materials.
Sources
- eCFR: 29 CFR 1910.155, Scope, application and definitions applicable to this subpart (as of Nov 3, 2026)Checked November 5, 2026
- eCFR: 29 CFR 1910.157, Portable fire extinguishers (as of Nov 3, 2026)Checked November 5, 2026
- eCFR: 29 CFR 1910.158, Standpipe and hose systems (as of Nov 3, 2026)Checked November 5, 2026
- eCFR: 29 CFR 1910.159, Automatic sprinkler systems (as of Nov 3, 2026)Checked November 5, 2026
- eCFR: 29 CFR 1910.164, Fire detection systems (as of Nov 3, 2026)Checked November 5, 2026
- eCFR: 29 CFR 1910.165, Employee alarm systems (as of Nov 3, 2026)Checked November 5, 2026
Other OSHA General Industry study guides: Walking-working surfaces, Exit routes and emergency planning, Electrical safety, Personal protective equipment, Hazardous materials, Permit-required confined spaces, Lockout/tagout, Machine guarding, Welding, cutting and brazing, Electric power generation, transmission and distribution, Powered industrial trucks (forklifts), Materials handling and storage, Bloodborne pathogens, Occupational noise exposure