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PORTABLE PROTECTION

Portable Fire Extinguishers
NFPA 10 Classes, Placement & ITM

Fire classes A through K, extinguisher types, travel-distance rules, and the monthly / annual / 6-year / 12-year service schedule that keeps them ready.

By Samektra · April 2026 · 9 min read

The Five Fire Classes

Ordinary combustibles

Wood, paper, cloth, rubber, most plastics

Flammable liquids

Gasoline, oil, grease, oil-based paint, solvents

Energized electrical

Wiring, panels, motors, appliances in service

Combustible metals

Magnesium, titanium, lithium, sodium, potassium

Cooking oils & fats

Commercial kitchen vegetable oils, animal fats

Extinguisher Types

ABC dry chemical (monoammonium phosphate)

A, B, C

The workhorse of general commercial occupancy. Leaves a yellow corrosive residue.

BC dry chemical (sodium or potassium bicarbonate)

B, C

Common in commercial kitchens (older installs) and some industrial settings. Cleaner than ABC.

Water (2.5 gal pressurized)

Schools, offices, light hazards. Must not be used on B, C, or K fires.

Wet chemical (potassium acetate)

K, A

Required for commercial kitchens under NFPA 10 §5.5.5. Cools and saponifies cooking oil.

CO₂

B, C

Leaves no residue — preferred for electronics, laboratories, and clean-room environments. Non-cooling.

Clean agent (Halotron, Novec 1230)

A, B, C

Halon replacement. Used where residue is a problem — data centers, museums, aircraft cockpits.

Dry powder

Specific to combustible metal fires. Different agents for different metals.

Placement & Travel Distance

NFPA 10 classifies each occupancy's fire hazard as Light, Ordinary, or Extra, and sets maximum travel distance from any point in the building to an extinguisher:

Class A75 ft max75 ft max75 ft max

Class B50 ft max50 ft max30 ft max

Class K (kitchens)30 ft max30 ft max30 ft max

LIGHT HAZARDORDINARYEXTRA

Mounting height is limited: extinguishers over 40 lb must be mounted with the top no higher than 3½ ft from the floor; extinguishers under 40 lb can be up to 5 ft. No part of the extinguisher or bracket may be less than 4 inches off the floor.

NFPA 10 ITM Schedule

MonthlyQuick visual check — extinguisher in place, accessible, pressure gauge in the green, tamper seal intact, signage visible.§7.2

AnnualProfessional maintenance by a certified technician — weigh, inspect, verify contents and mechanical integrity. New certification tag attached.§7.3

6-YearInternal examination for most stored-pressure dry chemical types. Discharge, inspect interior, refill.§8.3

12-YearHydrostatic test of the cylinder — pressure test to verify the steel/aluminum is still sound. (5 years for CO₂ and pressurized water.)§8.3

References

1. NFPA 10 (2022): Standard for Portable Fire Extinguishers.

2. UL 711: Rating and Fire Testing of Fire Extinguishers.

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Discussion (2)

You

Mike R.Fire Inspector· 3 days ago

Great breakdown of the technical details. The NFPA 25 maintenance table is exactly what I needed for my ITM schedule.

▲ 8Reply

Sarah L.Safety Officer· 1 week ago

Really clear explanation. Would love to see a companion video walkthrough of the inspection process.

▲ 5Reply