The escape hood SR 76-3 Chem is designed for use as a respirator during evacuation in the event of chemical accidents. The hood is intended only as an escape hood for single-use and provides protection only when the surrounding air has a normal oxygen content (17–21%). Maximum usage time: 30 minutes. The escape hood SR 77-3 Smoke is designed for use as a respirator during evacuation in the event of fire or chemical accidents. The hood is intended only as an escape hood for single-use and provides protection only when the surrounding air has a normal oxygen content (17–21%). Maximum usage time: 30 minutes. The hood is equipped with a gas filter ABEK1-CO, a particulate filter of class P3, and provides protection against carbon monoxide and other toxic gases, as well as particles that may be released during a fire or chemical accidents. Type A1 provides protection against organic gases and vapors, such as solvents, with a boiling point above +65 °C. Type B1 provides protection against inorganic gases and vapors, such as chlorine, hydrogen sulfide, and hydrogen cyanide. Type E1 provides protection against acidic gases and vapors, such as sulfur dioxide and hydrogen fluoride. Type K1 provides protection against ammonia and certain amines, such as ethylenediamine.