Respirator Canister Evaluation for Selected Organic Vapors and Sorbent Performance Against Vinyl Chloride

摘要

The protection afforded by one commercial organic vapor respirator canister (MSA/GMA) against chloroform, benzene, epichlorohydrin, acrylonitrile, propargyl alcohol, 1,2-dibromoethane, acrolein, chloromethyl methyl ether, and N-nitrosodimethylamine was determined. Six canisters simultaneously were challenged at 64 actual liters per minute with test atmospheres of these compounds at both 80% and < 15% relative humidity (RH). Breakthrough volume was defined as that volume of air which passed through the canister before the downstream concentration was 1% of the challenge concentration. Tests were continued until at least this concentration was attained or 16 h had elapsed, whichever occurred first. Under a moderate workload, these canisters should afford adequate protection against chloroform, benzene, and acrylonitrile for at least 4 h, epichlorohydrin for at least 8 h, and the remaining compounds (except chloromethyl methyl ether) for at least 16 h. Chloromethyl methyl ether at 80% RH exhibited a minimum penetration of 30% after only 34 min, and it appears that this and similar canisters will not provide adequate protection against atmospheres containing this compound. In all tests in which breakthrough occurred, the decrease in breakthrough time with increase in relative humidity was greater than would be expected from published literature. The capacities of a charcoal and Ambersorb 347 for vinyl chloride were determined. Challenge atmospheres were 10-ppM vinyl chloride at both 80% and < 15% RH. At 1% penetration, the calculated charcoal capacity was 2.0 mg of vinyl chloride per gram of sorbent at < 15% RH, and 0.52 mg/gm at 80% RH. The corresponding capacities for Ambersorb 347 were 0.68 and 0.36. Both sorbents, when used in respirator equipment, appear only marginally useful against vinyl chloride. (ERA citation 06:008057)