One of the top questions we get when working with clients whose primary business is storing, handling, and processing flammable liquids is...
How many flammable storage cabinets can we have in the same area?
This answer used to be easy, but these days - not so much. Back in the day, NFPA 30 (2000 Edition) stated the answer clearly...
4.3.2 Not more than three storage cabinets shall be located in any one fire area.
Exception No. 1: In an industrial occupancy, additional storage cabinets shall be permitted to be located in the same fire area, if a minimum separation of 100 ft (30 m) is maintained between each group of not more than three cabinets.
Exception No. 2: In an industrial occupancy that is protected by an automatic sprinkler system that is designed and installed in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems, the number of cabinets in any one group shall be permitted to be increased to six.
In the 2015 Edition of NFPA 30 we find the following:
9.5.2 The total aggregate volume of Class I, Class II, and Class IIIA liquids in a group of storage cabinets shall not exceed the maximum allowable quantity of flammable and combustible liquids per control area based on the occupancy where the cabinets are located.
I know what your thinking... that is all about what NFPA 30 requires; how about what OSHA requires?
When we look to OSHA for the requirements we have two clearly DIFFERENT requirements, depending on what industry you're working in. What I mean by this is that OSHA's construction standard for flammable liquids (1926.152) has a very different requirement than anything we can find in OSHA's general industry standard for flammable liquids (1910.106).
In 1926.152 we see the following: (emphasis added by me)
1926.152(b)(3) Not more than 60 gallons of Category 1, 2 and/or 3 flammable liquids or 120 gallons of Category 4 flammable liquids shall be stored in any one storage cabinet. Not more than three such cabinets may be located in a single storage area. Quantities in excess of this shall be stored in an inside storage room.
In 1910.106 we see the following:
1910.106(d)(3)(i) Maximum capacity. Not more than 60 gallons of Category 1, 2, or 3 flammable liquids, nor more than 120 gallons of Category 4 flammable liquids may be stored in a storage cabinet.
We can see there is no type of limitation in 1910.106 as to how many cabinets OSHA limits to a storage area. One could surmise that OSHA took into consideration that a general industry area would have built-in fire protection in it's construction (i.e. firewalls), it's fire protection (i.e. sprinklers or fire extinguishers) so they did not limit the number of cabinets. This would be in contrast to storing flammable liquids in a building that is under construction that does not yet have its full fire protection design in place during its construction phase.
So to be clear, OSHA's general industry standard does NOT limit the number of cabinets that be in the same area. But if you're looking for the best guidance to ensure the safest workplace you could use the "construction standard" and limit your cabinets to three (3) per storage area. But if you're looking for the best guidance we turn to NFPA 30, 2015 edition which limits us in the following manner - total aggregate volume of Category 1, 2, 3 flammable liquids in a group of storage cabinets shall not exceed the maximum allowable quantity of flammable and combustible liquids per control area based on the occupancy where the cabinets are located.