UL 1604 certification allows products to be used in potentially explosive environments found in oil and gas, petrochemical, aviation and other industries. Fully-rugged and ultra-mobile-rugged  mobile computers can be configured to provide safe, reliable mobile computing solutions for spark-free use. UL 1604-approved versions of fully-rugged Toughbook models are available for use in Class I, Division 2, Groups A, B, C and D environments. These are defined as places where flammable gases, vapors and liquids are present during abnormal or accident conditions.