Apr 26 2017

Oxygen Cylinders in Fire Rated Cabinets

Q: In regards to oxygen cylinder storage, if the quantity of gas in storage is between 300 and 3000 cubic feet in a smoke compartment and the full cylinders are being stored in a fire-rated medical gas cabinet, the hospital was told that they do not need to be stored in a specially designated room. They were told the fire-rated cabinets act as a room themselves and they could place the cabinets anywhere in the smoke compartment. I don’t see it that way, and I believe that the cabinets only allow the cylinders to be stored without the need for separation from combustibles. Question is: What is permitted?

A: I believe you are correct. Section 11.3.2 of the NFPA 99-2012 says storage of non-flammable gases greater than 300 cubic feet but less than 3,000 cubic feet shall comply with the requirements of 11.3.2.1 through 11.3.2.3. Section 11.3.2.1 says storage locations shall be outdoors or within an enclosed interior space of noncombustible or limited combustible construction, with doors that can be secured against unauthorized entry. Section 11.3.2.2 says oxidizing gases cannot be stored with flammable gases, liquids or vapors.

11.3.2.3 says oxidizing gases must be separated from combustibles by one of the following:

  • Minimum of 20 feet
  • Minimum of 5 feet if the entire storage location is sprinklered
  • Enclosed cabinet on noncombustible construction having a minimum fire protection rating of ½ hour.

So… there you have it. Those yellow “Fire Cabinets” are double-walled construction and really only rated for 30 minutes and they are commonly called “NFPA 30” cabinets. But they are permitted to be used in lieu of having to meet the 5 foot or 20 foot distance requirement inside a designated room that is constructed with noncombustible or limited combustible materials, and has a door that is lockable. Limited combustible materials are traditionally gypsum wall board that has a thin layer of paper on the surface.

But make no mistake about it… while the oxygen cylinders may be stored inside the metal cabinets, they still must be stored inside a designated room with a lockable door.