Educational resource only. Definitions reflect common U.S. usage under NFPA 10 and related standards.
Floridafloridafiresafety.org

Glossary of Key Terms

Every abbreviation and jargon term you'll encounter on a service invoice, inspection report, or fire-code document — translated into plain English.

A

ABC Extinguisher
A dry-chemical extinguisher rated for Class A, B, and C fires. The most common general-purpose commercial extinguisher in the United States. Agent is monoammonium phosphate.
AHJ (Authority Having Jurisdiction)
The individual or office with legal authority to enforce fire codes in your area — usually a state fire marshal, a city fire marshal, or an inspector from the local fire department. When codes conflict, the AHJ makes the final call.
Agent
The actual substance inside an extinguisher (dry chemical powder, CO₂ gas, wet chemical, water, clean agent, etc.).
Annual Maintenance
The once-a-year external inspection and service of an extinguisher, performed by a licensed technician, after which a new dated tag is affixed. Required by NFPA 10.
Approved
In code language, "acceptable to the AHJ." Often used interchangeably with "listed," but subtly different: a product can be listed by UL but not approved by a specific AHJ for a specific use.

C

CO₂ Extinguisher
A carbon-dioxide extinguisher, rated for Class B and C fires. Leaves no residue, making it popular for electrical equipment and electronics.
Class A / B / C / D / K
The five U.S. fire classifications by fuel type — ordinary combustibles / flammable liquids / energized electrical / combustible metals / cooking oils.
Clean Agent
A category of extinguishing agents (Halotron I, FE-36, Novec 1230) that leave no residue and do not conduct electricity. More expensive than dry chemical; used where cleanup matters.
Condemned
A finding by a service technician that an extinguisher cannot be returned to service (due to corrosion, pitting, damage, weight loss, etc.) and must be scrapped.
Commercial Cooking Equipment
Any cooking appliance that produces grease-laden vapors (fryers, ranges, griddles, woks, charbroilers). Triggers Class K extinguisher and NFPA 96 hood-suppression requirements.

D

Dry Chemical
A powdered extinguishing agent. The most common commercial agent is monoammonium phosphate (ABC); sodium bicarbonate (BC) and potassium bicarbonate ("Purple-K," BC) are also used.

E

Egress
The path of travel from any occupied space to a public way outside the building. Fire codes regulate width, illumination, door hardware, and obstruction of egress paths.

F

Fire Marshal
A government official (state or municipal) responsible for enforcing fire codes, investigating fires, and permitting regulated activities. Often the AHJ for your business.
Fire Rating
The numeric/alphabetical classification of an extinguisher's capability — e.g., "2A:10B:C" means it has the stopping power of 2 A-units, 10 B-units, and is safe on electrical fires. Higher numbers mean more capacity.
Flammable Liquid
A liquid with a flash point below 100°F. Storage regulated by OSHA 29 CFR 1910.106. Class IA has the lowest flash point and is most restricted.

H

Halon / Halon 1211
A legacy clean-agent extinguisher. Production banned in 1994 due to ozone depletion, but existing units can still be recharged with recycled agent. Largely replaced by Halotron I, FE-36, and Novec 1230.
Hydrostatic Test ("Hydrotest")
A high-pressure water test of the extinguisher cylinder to verify structural integrity. Required every 12 years for dry-chemical cylinders, every 5 years for CO₂ and water-mist.

I

IFC (International Fire Code)
A model code published by the International Code Council and adopted, with amendments, by most U.S. states. Incorporates NFPA standards by reference.
Internal Maintenance (6-Year Service)
Complete disassembly of a stored-pressure extinguisher, inspection of the interior, replacement of seals/o-rings, and refill. Required every 6 years from the date of manufacture.

K

K-Class (Class K) Extinguisher
A wet-chemical (typically potassium acetate) extinguisher designed for commercial cooking oils. Required in any facility using commercial cooking equipment.

M

Monoammonium Phosphate (MAP)
The active agent in most ABC dry-chemical extinguishers. Yellow powder; mildly corrosive to metals over time.
Monthly Inspection
The quick visual check OSHA requires the employer to perform on every extinguisher once per month. Not a technician-level service; you do it yourself and log the date.

N

NFPA
The National Fire Protection Association — the non-profit that publishes most U.S. fire-protection technical standards.
NFPA 10
The Standard for Portable Fire Extinguishers. Governs selection, placement, inspection, maintenance, and testing.
NFPA 13
The Standard for the Installation of Sprinkler Systems.
NFPA 17A
The Standard for Wet Chemical Extinguishing Systems — governs commercial kitchen hood suppression systems.
NFPA 25
The Standard for Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems (sprinklers, standpipes, fire pumps).
NFPA 33
The Standard for Spray Application Using Flammable or Combustible Materials — governs paint-spray booths.
NFPA 96
The Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations — the "hood & duct" standard.

O

Obstructed
Of an extinguisher: not immediately visible or reachable from the approach path. A common citation item.
Occupancy
The classification of a building based on its use (business, mercantile, assembly, storage, etc.). Determines which code requirements apply.
OSHA
The Occupational Safety and Health Administration. Its rule at 29 CFR 1910.157 is the federal workplace requirement for portable fire extinguishers.

P

PASS
The acronym for using an extinguisher: Pull the pin, Aim at the base, Squeeze the handle, Sweep side to side.
Pre-Inspection
A voluntary walkthrough by a fire department or consultant before the official inspection, used to catch and fix issues without citation.

R

Rechargeable
Of an extinguisher: designed to be emptied, inspected, and refilled with new agent. Commercial-grade extinguishers are rechargeable; most big-box disposable units are not.
Recharge
The service of refilling and re-pressurizing an extinguisher after discharge or after scheduled internal maintenance. Typical cost in 2026: $18–$75 depending on agent and size.

S

Service Tag
The small paper or plastic tag attached to every commercial extinguisher showing the date and technician of the most recent service. Must be visible without moving the extinguisher.
Stored-Pressure Extinguisher
The most common modern design: the extinguisher is permanently pressurized, with agent and propellant sharing the same cylinder. Contrasts with older "cartridge-operated" designs.

T

Tamper Seal
A small plastic tie securing the pull pin. If broken, the extinguisher is assumed to have been discharged or tampered with and must be inspected.
Travel Distance
The actual walking distance (around furniture and through doorways) from any point in the building to the nearest extinguisher. Not line-of-sight.

U

UL (Underwriters Laboratories)
A nationally recognized testing laboratory. "UL-listed" extinguishers have been tested and certified to the relevant UL safety standard. Look for the UL mark on the label.

W

Wet Chemical
A liquid extinguishing agent (typically potassium acetate) used in Class K extinguishers and kitchen-hood suppression. Reacts with hot cooking oil to form a soapy barrier that smothers and cools the fire.

Back to Home · Compare pricing on Cost & ROI · Walk your space with the Self-Audit Checklist.