Specifically, OSHA mandates that secondary containment systems must be in place to prevent the discharge of flammable or combustible liquids in case of a primary container failure. OSHA's regulation for secondary containment is found in 29 CFR 1910.120 which says "Where major spills may occur, a spill containment program...shall be implemented to contain and isolate the entire volume of the hazardous substance being transferred."
The regulation specifies that secondary containment systems must have sufficient capacity to contain the entire volume of the primary container plus an additional amount, typically 10% of the volume of the largest container stored within the containment area, or 100% of the volume of the largest container, whichever is greater. Additionally, the containment system must be constructed of materials compatible with the stored liquids and must be maintained to ensure its effectiveness.
