Q: It is my understanding that you are only allowed to have 10 gallons of flammable chemicals in a smoke compartment without having a fire cabinet. Does this amount change if it’s a one hour fire rated, fully sprinkled room?
A: According to section 9.4.3 of NFPA 30 Flammable and Combustible Liquids Code, 2012 edition, the storage of Class IB flammable liquids (which is the typical flammable liquids you would find in a hospital, such as ethyl-alcohol) is limited to 5.3 gallons (20 L) per container made of metal, approved plastic, and safety cans.
According to section 9.5.1 of NFPA 30, to total volume of Class I, Class II, and Class IIIA liquids stored in an individual storage cabinet cannot exceed 120 gallons (460 L). The description of an approved storage cabinet is listed in section 9.5.3 (2) which is the type that used to be referred to as “fire-rated” storage cabinets, or “NFPA 30” cabinets. They basically stopped calling these cabinets “fire-rated” and refer to them now by their construction. Incidentally, section 9.5.4 does not require storage cabinets to be ventilated, even though ventilation openings are usually provided.
The maximum allowable quantity of flammable liquids (outside of storage areas) per control area is 10 gallons (38 L) for healthcare occupancies. A control area is defined by NFPA 30 as an area protected with fire-rated barriers. So, technically, smoke compartment barriers in a healthcare occupancy would typically not comply with the NFPA 30 definition of a control area, because smoke compartment barriers doors typically do not comply with the requirements for fire-rated doors. However, CMS and the accreditation organizations have overlooked this detail and allow smoke compartment barriers to serve as control areas for the purpose of storing Alcohol Based Hand-Rub (ABHR) product, which contains ethyl-alcohol.
According to 9.3.6 of NFPA 30, Class I flammable liquids are not permitted to be stored in floors below the level of exit discharge (basements).
Fire resistive rating for rooms for the storage of flammable liquids is dependent on the area of the room. According to Table 9.9.1, a storage room no more than 150 square feet must have a fire resistive rating of 1-hour. A storage room greater than 150 square feet but no more than 500 square feet must have a fire resistive rating of 2-hours. Storage rooms greater than 500 square feet are not permitted, unless you meet the more extreme requirements of a flammable liquid warehouse.
So, you can store up to 120 gallons of Class IB flammable liquids in a storage cabinet that meets the requirements of section 9.5.1 of NFPA 30, but the total quantity does not change if the flammable liquid is stored in a properly fire-rated storage room based on the total area of the room. Be advised that NFPA 30 does not differentiate whether the storage room is sprinklered or not.
However, I disagree with your opening statement that you are allowed to have 10 gallons of flammable chemicals in a smoke compartment without having a fire cabinet. NFPA 30 section 9.4.3 limits the maximum volume to 5.3 gallons of stored flammable liquids without have a fire cabinet.