The short answer
| Extinguisher gross weight | Top of extinguisher no higher than | Bottom clearance |
|---|---|---|
| 40 lb or less | 5 ft (60 in) above the floor | At least 4 in above the floor |
| More than 40 lb | 3.5 ft (42 in) above the floor | At least 4 in above the floor |
These are the NFPA 10 (Standard for Portable Fire Extinguishers) installation heights most fire codes adopt. Your local code and fire marshal have the final word, so confirm against the edition your jurisdiction uses.
What OSHA requires
OSHA does not set a number. It requires employers to mount, locate and identify portable extinguishers so they are readily accessible to employees without exposing them to possible injury (29 CFR 1910.157(c)(1)). Following the NFPA 10 heights is the usual way to show that.
ADA: reach range and protruding objects
The 2010 ADA Standards for Accessible Design affect extinguisher cabinets in two ways:
- Protruding objects. Objects with a leading edge between 27 in and 80 in above the floor may protrude no more than 4 in into a circulation path, so a person using a cane can detect them. A surface mounted cabinet deeper than 4 in in a corridor can create a problem, which is why semi-recessed and recessed cabinets are common in public hallways.
- Reach range. Operable parts should be within the accessible reach range, generally no higher than 48 in above the floor for an unobstructed forward or side reach, and operable with one hand without tight grasping, pinching or twisting.
Sources: 2010 ADA Standards (U.S. Access Board), sections 307 Protruding Objects and 308 Reach Ranges.
Putting it together for a cabinet
- Pick the extinguisher first. Its gross weight sets the maximum height of its top.
- Pick a cabinet that fits it with room to lift it out.
- Check the corridor: if the cabinet would project more than 4 in into a walkway in the 27 in to 80 in zone, use a semi-recessed or recessed model.
- Set the cabinet so the extinguisher inside meets the NFPA 10 height and the door handle sits within reach range.
- Keep the location consistent floor to floor and keep it unobstructed.
An extinguisher that is mounted correctly but cannot be seen is still hard to use. HighVis keeps the same mounting logic and adds an etched, edge-lit door with a battery backup, so the location stays visible in a power failure. See the HighVis Cabinet.