This respirator can be used for protection against toxic dusts, fumes, solids and aqueous-solid aerosols. The Inner surface cotnains a circular pvc foam for a full seal. It is to be used in concentration of contaminants up to 20 times the Occupational Exposure Level (PEL). These masks should be worn for protection against asbestos fibers, zinc, cadmium, arsenic, chrome and cobalt.