Now get triple assurance with a single suit certified to NFPA 1991 base plus optional Flash Fire and Liquified Gas requirements. Frontline® 500 offers three-way protection - broad chemical holdout, plus flame resistance and superior radiant heat protection for the additional hazards encountered in a chemical flash-fire. Chemical, flash, radiant - three hazards, one suit. With Frontline® 500, Kappler’s got your back - and your front.