What are the four classes of fire?

There are four classes of fires. All fire extinguishers are labeled, using standard symbols, for the classes of fires on which they can be used. A red slash through any of the symbols tells you the extinguisher cannot be used on that class of fire. A missing symbol tells you only that the extinguisher has not been tested for a given class of fire, but may be used if an extinguisher labeled for that class of fire is not available.

Types of Fires:

  • CLASS A: Ordinary combustibles such as wood, cloth, and paper.
  • CLASS B: Flammable liquids such as gasoline, oil, and oil-based paint.
  • CLASS C: Energized electrical equipment, including wiring, fuse boxes, circuit breakers, machinery and appliances.
  • CLASS D: Combustible metals such as magnesium or sodium.

When should I use a fire extinguisher?

Portable extinguishers are not designed to fight large or spreading fires. Even against small fires, they are useful only under certain conditions:

  • The operator must know how to use the extinguisher.
  • The extinguisher must be within easy reach, in working order, and fully charged.
  • The operator must have a clear escape route that will not be blocked by fire.
  • The extinguisher must match the type of fire being fought. (Extinguishers containing water are unsuitable for use on grease or electrical fires.)
  • The extinguisher must be large enough to put out the fire. Many portable extinguishers discharge completely in as few as eight to ten seconds.
  • Always be sure the fire department inspects the fire site, even if you think you've extinguished the fire.

How do I know if I have enough fire extinguishers?

The standard rule of thumb is a travel distance of no more than seventy-five feet for Class “A” hazards and fifty feet travel distance for Class “B” hazards.

These are general guidelines and can differ based on many factors. Fire Extinguisher spacing is addressed in
NFPA 10 (Standard for Portable Fire Extinguishers) section

CLASS A: Fires with trash, wood, paper or other combustible materials as the fuel source.
CLASS B: Fires with flammable or combustible liquids as the fuel source.


How often must I have my fire extinguishers serviced?

It is the owners’ responsibility to inspect the fire extinguishers at a minimum of thirty day intervals. Fire extinguishers shall be inspected at more frequent intervals when circumstances require.

Fire extinguishers shall be subjected to maintenance at intervals of not more than 1 year, at the time of hydrostatic test, or when specifically indicated by an inspection or electronic notification.

Maintenance Record Keeping: Each fire extinguisher shall have a tag or label securely attached that indicates the month and year the maintenance was performed, identifies the person performing the work, and identifies the name of the agency performing the work.


How can I tell how old my fire extinguisher is?

All fire extinguishers have a "Born On" date. On the chrome liquid types, that date is usually found on the hanger loop. On the reqular ABC, BC, or Halon extinguishers that date is uaually found on the label, however some manufacturers stamp the date in the "boot" located around the extinguisher base. Some manufacturers stamp the date in the bottom. On the CO2 type extinguishers this date is found stamped around the shoulder near the top.

What is that plastic collar around the neck of my extinguisher when it was returned back to me?

All dry chemical type extinguishers as well as water based and CO2 brought in for 6yr maintenance, hydrotest, or recharge will have verification collars attached as proof of depressurization, devalving, and internal maintenace.