1.1 Purpose. The explosive atmosphere test is performed to: a. demonstrate the ability of materiel to operate in fuel-air explosive atmospheres without causing ignition, or b. demonstrate that an explosive or burning reaction occurring within encased materiel will be contained, and will not propagate outside the test item. 1.2 Application. This method applies to all materiel designed for use in the vicinity of fuel-air explosive atmospheres associated with aircraft, automotive, and marine fuels at or above sea level. Procedure II specifically relates to atmospheres in a space in which flammable fluids or vapors exist, or can exist, either continuously or intermittently (e.g., in fuel tanks or within fuel systems).