floridafiresafety.orgWho writes the rules, and who enforces them?
Three layers of authority sit on top of every business in the United States. They don't always agree on detail, but they stack like this — when they disagree, the strictest rule wins.
| Layer | Who they are | What they govern |
|---|---|---|
| Federal (OSHA) | U.S. Department of Labor — 29 CFR 1910.157 | The mandatory workplace-safety floor. Applies to employees. Cannot be waived. |
| Consensus Standard (NFPA 10) | National Fire Protection Association | The technical standard most state and local codes adopt by reference. Once adopted, it's law. |
| AHJ — Authority Having Jurisdiction | Your State Fire Marshal, City Fire Marshal, or fire department inspector | The person who actually walks your building, applies local amendments, and signs (or refuses) your certificate. |
OSHA vs. NFPA 10 — what's the difference?
This is the question small business owners search most, and the answer is less confusing than it looks.
OSHA 29 CFR 1910.157
A workplace-safety rule. It's short, blunt, and enforceable through fines. It covers four things:
- You must provide extinguishers accessible to employees.
- Extinguishers must be selected based on the hazard.
- They must be visually inspected monthly by the employer.
- They must receive an annual maintenance check and a hydrostatic test at required intervals.
OSHA does not tell you exactly how far apart to place extinguishers, how high to hang them, or how to size them by hazard class. For that, OSHA defers to the technical standards — primarily NFPA 10.
NFPA 10 (Standard for Portable Fire Extinguishers)
The technical "how." When adopted into a state or local fire code, it becomes binding. It covers:
- Hazard classification (Light, Ordinary, Extra).
- Extinguisher sizing by square footage.
- Specific maximum travel distances by class.
- Mounting height and obstruction rules.
- The full service cadence (annual / 6-year / 12-year).
Most U.S. jurisdictions adopt the latest NFPA 10 on a 3-year cycle. As of 2026, the current edition is NFPA 10 (2022) in most states, with some already on NFPA 10 (2025). Your AHJ can tell you which edition applies.
Travel-distance rules (the "75-foot rule" and friends)
Travel distance is the path an employee would actually walk — around furniture, through doorways — to reach the nearest extinguisher. Not line-of-sight. This is the single most common placement mistake we see at inspection.
| Hazard Class | What it covers | Max travel distance | Typical minimum size |
|---|---|---|---|
| Class A | Ordinary combustibles — paper, wood, fabric, most office settings | 75 ft | 2-A (≈ 2.5 lb ABC) |
| Class B (Low hazard) | Small amounts of flammable liquids | 50 ft | 10-B |
| Class B (High hazard) | Large flammable-liquid exposure (auto shops, paint booths) | 30 ft | 40-B or higher |
| Class C | Energized electrical equipment | Same as A or B (whichever hazard is present) | Non-conductive agent required (ABC or CO₂) |
| Class D | Combustible metals (magnesium, titanium, lithium) | 75 ft of the hazard | Specialized dry-powder agent |
| Class K | Commercial cooking oils and fats | 30 ft of the cooking appliance | Wet chemical (required in commercial kitchens) |
Mounting, signage, and accessibility
These details cost small businesses more inspection failures than any other category. They are trivial to fix in advance.
- Mounting height: Extinguishers weighing 40 lb or less — the top of the extinguisher must be no more than 5 feet above the floor. Heavier than 40 lb — no more than 3.5 feet. The bottom must be at least 4 inches off the floor.
- Visibility: Must be "conspicuous" and unobstructed. If it's tucked behind a coat rack, a stack of boxes, or a holiday display, it fails.
- Signage: If the extinguisher isn't immediately visible from the approach path (common in warehouses and high-rack storage), a sign is required to indicate its location.
- ADA clearance: Extinguishers that protrude more than 4 inches from the wall into a path of travel must be recessed or have a detectable base — this is an ADA requirement your fire marshal may or may not flag, but your general-contractor permit inspection certainly will.
- Tag in plain view: The service tag must be attached so the most recent service date is visible without removing the extinguisher.
The monthly, annual, 6-year, and 12-year cadence
The single biggest source of confusion — and the biggest driver of surprise invoices — is the four-tier service schedule. Each tier has a different cost, a different person authorized to do it, and a different penalty for missing it.
| Interval | Who performs it | What happens | Documentation |
|---|---|---|---|
| Monthly visual inspection | You (the employer/owner) | Verify location, access, pressure gauge in green, pin & tamper seal intact, no damage or corrosion. | Initial and date the back of the tag, or keep a log. OSHA requires record retention. |
| Annual maintenance | Licensed service company | Thorough external inspection, weight check, tag replacement. | New dated service tag affixed to the extinguisher. |
| 6-year internal maintenance | Licensed service company | Extinguisher is emptied, disassembled, internally inspected, and refilled (stored-pressure types). | Internal-service label affixed; next due date recorded. |
| 12-year hydrostatic test | Licensed / certified hydrotest facility | Cylinder is pressure-tested to verify structural integrity. Dry-chemical cylinders are tested every 12 years; CO₂ and water-mist cylinders every 5 years. | Permanent hydrotest label or stamp on the cylinder. |
"Do I need an extinguisher for a small ______?"
Short answer: almost certainly, yes. Here's the long answer by space type.
Small professional office (under 3,000 sq ft)
Typically one 2A:10B:C rated ABC extinguisher per floor, placed so no employee walks more than 75 feet to reach it. For most single-suite offices, a single 5-lb ABC near the main exit satisfies both OSHA and NFPA 10. Add a second if the layout has a long corridor or a separate wing.
Retail shop
One 2A:10B:C per ~3,000 sq ft of floor area is the NFPA 10 sizing for Light (Low) Hazard occupancy. Increase to Ordinary Hazard sizing (4A-rated) if you stock flammable stock such as cleaning products, solvents, or a significant amount of paper/cardboard. Travel distance still governs — 75 ft max for Class A.
Restaurant, café, or bakery with hot cooking
Two separate requirements apply. You need Class K coverage within 30 ft of every cooking appliance that produces grease-laden vapors (fryers, ranges, griddles, woks), and you need standard ABC coverage for the rest of the building. The Class K cannot substitute for the ABC and vice versa.
Warehouse or light manufacturing
Travel distance and sizing scale with stored commodity and rack height. Expect to need 4A or 10A rated extinguishers at shorter intervals, plus hose stations or standpipes above certain thresholds. This is the class of occupancy where an NFPA 10 professional sizing calculation is worth paying for.
Auto shop, garage, or body shop
Class B hazards dominate. Expect High Hazard sizing (40-B minimum, sometimes 80-B), 30-ft travel distance, and a separate extinguisher for any welding bay. Paint-spray booths have additional NFPA 33 requirements your local marshal will check for.
Home-based business / home office
OSHA generally does not apply to a home-office-of-one with no employees, but many commercial landlords, HOAs, and business-liability insurers require at least one ABC extinguisher on premises. And of course — you want one anyway.
Common searches, answered
"Is a fire extinguisher required by law in every state?"
In every U.S. state for any workplace with employees, yes — via OSHA. State fire codes add additional details (count, placement, class) and typically apply to any commercial occupancy whether you have employees or not.
"Can I use the extinguisher I bought at the hardware store?"
Legally — if it's UL-listed and properly rated for your hazard, yes. Practically — many disposable big-box units have non-rechargeable valves and are designed as a one-shot residential tool. A professional service company may refuse to tag them because there's no path to recharge or internal maintenance. See the Cost & ROI page for the full comparison.
"What fails inspections most often?"
In rough order: (1) missed annual service tag, (2) extinguisher obstructed or moved from its mounting, (3) wrong class for the hazard (almost always a missing Class K in a restaurant), (4) pressure gauge in the red, and (5) monthly inspection log missing or not maintained.
Go to the source
- OSHA 29 CFR 1910.157 — Portable Fire Extinguishers
- NFPA 10 — Standard for Portable Fire Extinguishers
- International Fire Code (IFC) — adopted by most states with local amendments
- Your state fire marshal's website (search "[your state] state fire marshal inspections")