Investigations by OSHA and the U.S. Chemical Safety Board (CSB) have documented a history of fires and explosions at workplaces (oilfields, refineries, chemical plants, and other facilities) where an internal combustion engine was identified as or suspected to be the source of ignition. Internal combustion engines present an ignition hazard when used in facilities processing flammable liquids and gases. If flammable vapors or gases are released in these facilities, an internal combustion engine could ignite the flammable materials with catastrophic consequences. OSHA’s new Internal Combustion Engines as Ignition Sources Fact Sheet (PDF*) helps employers and workers understand the risks involved in the use of internal combustion engines, as well as some of the control strategies that should be used to prevent such catastrophic events.