NFPA 10 Reference · San Francisco, CA
10 NFPA 10 Fire Extinguisher Rules Every Business Owner Must Know
Portable fire extinguishers are the most-cited line item on commercial fire inspections, because NFPA 10 has so many specific requirements and because extinguishers are easy for an inspector to check in sixty seconds. These ten rules cover 90% of what commercial buildings get wrong.
For San Francisco commercial buildings: this guide applies to properties across San Francisco · Bay Area. SoMa and FiDi high-rises require Class A NFPA 25 maintenance. Enforcement is handled by SF Fire Department.
Last updated: 2026-11-08 · Published by Fire Solutions NW · CA C-16 Licensed · Operating in 6 states
Monthly Visual Inspection With Initials on Tag
Every portable extinguisher requires a monthly visual inspection by someone at the facility — gauge in green, hose attached, seals intact, no damage, legible label, accessible. The person doing the inspection initials and dates the service tag each month.
Annual Service by a Licensed Technician
Every extinguisher must be externally serviced annually by a licensed technician. The tag is updated with the service date, technician initials, and license number. An annual service >12 months past is a routine citation.
6-Year Internal Maintenance (Dry Chemical)
Stored-pressure dry chemical extinguishers require 6-year internal maintenance — the extinguisher is opened, examined internally, and resealed. The service tag reflects this as the "6-year" check.
12-Year Hydrostatic Test
Most portable extinguishers require hydrostatic testing at 12-year intervals (5 years for CO2, water, and some others). After test, the cylinder gets a date-stamped hydrotest sticker. Expired = out of service.
Travel Distance Not to Exceed 75 Feet (Class A)
For ordinary Class A hazards, no point in the occupancy may be more than 75 feet from an extinguisher. Class B travel distances are shorter (30-50 ft depending on hazard). Big warehouses often fail this without realizing.
Mounting Height: Under 40 Pounds ≤ 5 Feet to Top
Extinguishers under 40 lb gross weight mount with the top no more than 5 feet above floor. Over 40 lb (water cans, big dry chem): 3.5 feet to top. Floor clearance 4 inches minimum.
Visibility and Access — Not Blocked, Clearly Marked
Extinguishers must be visible or marked with a sign. Blocked extinguishers (stored goods, display furniture, closed door) and extinguishers in locked cabinets without a break-glass are standard findings.
Minimum Rating by Occupancy and Area
Light-hazard occupancies need at least 2-A per extinguisher, 1 per 3,000 sqft, max 75 ft travel. Ordinary hazard = 2-A, 1 per 1,500 sqft. Extra hazard = 4-A, 1 per 1,000 sqft. Verify your coverage math — undersized ratings are citations.
Class K Required for Commercial Cooking
Any commercial cooking operation with vegetable oils or animal fats requires a Class K wet-chemical extinguisher within 30 ft travel distance of the cooking appliance. Kitchen without K = citation + potential shutdown.
Replace, Not Refill, When Damaged or Expired
Extinguishers with cracked or dented cylinders, missing parts, or past-hydrotest with no stamp must be removed from service. Do not refill — take it to a licensed shop for disposal and bring in a replacement.
Bottom line for San Francisco facility managers
Extinguisher compliance is cheap, mechanical, and visible. Monthly visual rounds by trained in-house staff + annual service by a licensed contractor covers 95% of everything NFPA 10 asks for. The 5% that remains — hydrotest cycles, travel distance math, Class K — is where contractors add the most value.
If you manage commercial property in San Francisco or nearby (Oakland, San Jose), Fire Solutions NW can audit against this list and clear any findings before your next AHJ inspection.
Have a specific question about your San Francisco facility?
We serve commercial buildings across San Francisco · Bay Area. Call us directly — 28+ years in the trade, and we self-perform in CA.