Fire Extinguisher Code
The NFPA regulations relating to fire extinguishers are part of NFPA 1, the Fire Code, that includes all of the regulations related to fire safety in permanent and temporary structures, fire investigation, fire suppression systems design, hazardous materials storage, training of firefighters and construction materials used to prevent the spread of fire. NFPA 10 contains the regulations on the portable fire extinguishers you see at work or have under the cupboard at home.
NFPA 11 contains the standards and regulations for systems that use foam, and NFPA 12 contains the regulations and standards for fixed fire suppression systems using carbon dioxide and Halon 1301. Fixed water sprinkler systems and foam-water systems, the ones you see in the ceiling at work, are covered by NFPA 15 and 16, and NFPA 17 covers dry chemical fire suppression systems other than portable fire extinguishers.
The code covers six different kinds of extinguishers and fire suppression systems. The one most often noticed is the portable, hand-held fire extinguisher with the label that instructs you to "pull pin; point nozzle at base of fire; sweep from side to side" These extinguishers, their inspection and placement are covered by NFPA 10, the regulations that require that fire extinguishers be inspected monthly (NFPA 10, Section 621) and have maintenance done yearly (NFPA 10, Section 631) by a licensed fire protection contractor.
NFPA 10 also specifies the minimum requirements, types of portable fire extinguishers and their locations in certain buildings under a variety of circumstances.
Fixed fire suppression systems are often thought of as "sprinkler systems" Most are water or foam-and-water combinations whose minimum standards for design, installation, inspection and operation are part of NFPA 13 and NFPA 15. Other commercial facilities, such as restaurants, use the carbon dioxide, Halon 1301 fixed systems covered by NFPA 12 and 12A; fixed sprinkler systems covered by NFPA 13, 13D and 13R; and dry chemical systems regulated by NFPA 17.
Fire extinguishers are usually only required in the workplace, although fixed systems may be required in multidwelling settings like hotels, apartments and condominiums. This means that, in addition to any local or state government requirements embodied in building codes, OSHA, the Occupational Safety and Health Administration of the federal government, is involved in the enforcement of the NFPA standards and regulations for fire prevention and suppression where those regulations relate to safety in the workplace.
Where portable extinguishers are located and keeping those locations accessible are enforced by OSHA under part of the US. Code (29 USC 1910157 (c)(1)).
Local Code Enforcement
The NFPA standards and regulations regarding fire extinguishers are the minimum standards. Cities, counties, parishes or states may have standards more stringent than those in the NFPA regulations, and those more stringent standards will be incorporated into their ordnances and laws.