Specifically designed for outdoor hazardous material storage and dispensing from 55-gallon drums containing flammable or combustible liquids. Outer wall is constructed of all-welded 16 or 12 gauge steel. Inner wall is constructed of 20 gauge steel. The double wall construction contains 3" of air space throughout. All Hazmat Storage Buildings are designed in accordance with the standards set forth by NFPA Code 30 and comply with OSHA and EPA regulations. All models are FM Approved for the storing and dispensing of flammable and combustible liquids. All electrical installations are U.L. Approved & Compliant to 1999 & 2002 NEC.