Questions keep arising regarding safety regulations for storage of alcohol and other flammable liquids in a laboratory. I hope what follows sheds some light on this issue.

Ethanol is classified as a Class IB combustible liquid, Class IB liquids have a maximum allowable container capacity of 20 liters in “metal (non-DOT approved) or approved plastic containers, safety cans or DOT specification metal drums.”

The amount of combustible liquids allowable is determined by the size of the “laboratory unit”. For hospitals with sprinkler systems, per 100 square feet of laboratory space, Class I, II and IIIA (including IB) flammable liquids are limited to 4 L (1.1 gallons) not in approved storage containers or safety cans and 7,5 L (2 gallons) total, including quantities in storage cabinets and safety cans.