This publication contains a listing of personal protective devices and reliable industrial hazard measuring instruments which have been evaluated by NIOSH and found acceptable for use as of October 1, 1986. Certified coal mine dust personal sampler units are listed along with the names and addresses of manufacturers and distributors. Data is provided on the effectiveness and use of self contained breathing apparatus. Gas masks for protection against acid gases, organic vapors, ammonia (7664417), chlorine (7782505), sulfur-dioxide (7446095), carbon-monoxide (630080), pesticides and other gases and vapors are discussed. Supplied air respirators are discussed, including Type-C continuous flow, Type-C pressure demand, Type-C demand, Type CE continuous flow abrasive blasting, Type-A, and Type-B. Particular respirators described include those for single use, for dust and mists, for dusts, fumes and mists, and for high efficiency usage. Chemical cartridges used to prevent exposure to ammonia, methyl-amine (74895), chlorine, hydrogen-chloride (7647010), sulfur-dioxide, organic vapors, paints, lacquers and enamels, pesticides, vinyl-chloride (75014), and other gases and vapors are described. Powered air purifiers are discussed. Also included in this report are the NIOSH policy statement on approval of air purifying respirators with end of service life indicators, the NIOSH policy statement on use of respirators for protection against asbestos (1332214), and the NIOSH and OSHA testing and certification of positive pressure closed circuit self contained breathing apparatus.