A Guide to NFPA And OSHA Fire Extinguishers Standards

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Fire safety is a serious matter. We always take it for granted thinking that we are fine as long as we are not putting things on fire on purpose and following common sense. However, fire prevention is the first pillar of fire safety. The nature of ignition can be very unpredictable. Fires can happen due to events that can’t be foreseen or controlled such as spontaneous ignitions or natural phenomena. This is where the second pillar of fire safety comes in – fire response.

There are a lot of features designed specifically to provide a fast and near-automatic response to ignition, yet the most reliable and affordable one is still a fire extinguisher. During 2019 fires caused around $15 billion in property loss across the US. The fact is that most of this damage could have been prevented by the timely response to a fire threat with a simple fire extinguisher. Despite how simple extinguishers seem to be there are standards that regulate their usage. Thus, we analyzed OSHA and NFPA fire extinguisher regulations to provide you with a convenient guide on these regulations.

General Requirements To Fire Extinguishers

The history of fire extinguishers shows an evolution of their design. As progress moved forward people discovered new components that helped fight different types of fire more effectively. On the other hand, some chemicals and design solutions that people used to trust are now deemed too dangerous for our health. That is why OSHA and NFPA formed a list of permitted fire extinguishers regarding their extinguishing agents or design features.

To be sure that your fire extinguisher is compatible with OSHA and NFPA requirements check that it DOES NOT contain:

Soda acid;
Chemical foam, unless it’s film-forming agents;
Carbon tetrachloride, methyl bromide and chlorobro-momethane;
Cartridge-operated water or loaded stream.

Besides, a proper fire extinguisher MUST HAVE NONE of such design features:

Copper or brass shell that is joined by soft solder or rivets;
CO₂ extinguishers with metal horns;
Solid-charge type AFFF;
Extinguishers that need to be inverted to operate;
Any extinguisher marked with 4B, 6B, 8B, 12B, and 16B fire rating
Stored pressure water extinguisher with a fiberglass shell.

Selection And Placement Of Fire Extinguishers

Both OSHA and NFPA recognize the same nation-wide classification of fire extinguishers. Types of fire extinguishers are distinguished regarding the class of fire threat they can fight off. These classes are A, B, C, D, and K.

OSHA dictates that portable fire extinguishers are placed in such a way that it is easy to access them at all times. Depending on the class of potential threat the travel distance to a fire extinguisher shouldn’t be greater than 75 ft, and less than 50 ft for class B fire threats.

As for the number of extinguishers per floor or area, NFPA recommends that there are:

Class A fire extinguisher – 1 per 11,250 ft²;
Class B fire extinguisher – at least 2 per 1ft² of the flammable liquid potential surface;
Class C fire extinguisher – 1 per area with electric hardware;
Class D fire extinguisher – depending on the size of working are and properties of a combustible metal;
Class K fire extinguisher – 1 per 5ft³ of the cooking appliance box.

Fire extinguishers should be mounted on the walls in such a way that they don’t become an obstacle to the normal workflow. Additionally, when choosing a place to store an extinguisher you need to make sure nothing will damage it. On the other hand, fire extinguishers should be always easily reachable and well labeled for the case of an emergency.

According to NFPA, a top of any extinguisher under 40lb needs to be at maximum heights of 5ft from the ground. Any other extinguishers heavier than 40lb must be mounted so the top would appear at under 3¹/₂ft from the ground. The marking of the location of fire extinguishers has to be bright, noticeable, and visible from any travel distance.

Maintenance Of Fire Extinguishers

Inspection and servicing of fire extinguishers are essential for their proper functionality. Every type of fire extinguisher requires special care, and it is the responsibility of the owner of an extinguisher to follow the maintenance schedule accordingly. Nevertheless, every extinguisher – no matter its type – needs to be inspected at least once a year. Such check-ups should be aimed at detecting depressurization and physical damage to the shell, nozzle, hose, or handle of the extinguisher. Hydrostatic test timeframes highly depend on the extinguishing agent. Here are those timeframes according to OSHA:

Every 5 years – Cartridge-operated water and/or antifreeze, Stored pressure water and/or antifreeze, Wetting agent, Foam (stainless steel shell), Aqueous Film Forming foam (AFFF), Loaded stream, Dry chemical with stainless steel, Carbon Dioxide.

Every 12 years – Dry chemical, stored pressure, with mild steel, brazed brass or aluminum shells, Dry chemical, cartridge or cylinder operated, with mild steel shells, Halon 1211, Halon 1301, Dry powder, cartridge or cylinder operated with mild steel shells.

Be advised that only fire equipment specialists can provide this kind of service. After each maintenance check, the owner of fire-fighting equipment needs to make sure that the servicing tag on their extinguisher is up-to-date.