Flammable liquids are classified based on their flash point and boiling point. NFPA 30 addresses the definition and classification of flammable and combustible liquids, and establishes three classes as follows:
- Class IA – Flash Point less than 73°F; Boiling Point less than 100°F
- Class IB – Flash Point less than 73°F; Boiling Point equal to or greater than 100°F
- Class IC – Flash Point equal to or greater than 73°F, but less than 100°F
- Class II – Flash Point equal to or greater than 100°F, but less than 140°F
- Class IIIA – Flash Point equal to or greater than 140°F, but less than 200°F
- Class IIIB – Flash Point equal to or greater than 200°F
29 CFR 1910.106 is OSHA’s standard on flammable liquids. Flammable chemicals must be stored in approved flammable cabinets and used in chemical fume hoods. Depending on the volume and other considerations, they may also need to be bonded and grounded. Storage limits are found in the Building Code and vary by floor. Any floor above the third has greatly reduced limits. The local fire department enforces the storage limits imposed by the building code, and issues flammable storage permits for the storage and use of flammable materials. The requirements for obtaining flammable storage permits vary by town, but most towns require permits for any amount of flammables on-site.