Checking seals of breathing masks - using ethanol-sensitive test strip in atmos. contg. ethanol

摘要

The seals of breathing masks are checked by exposing the wearer to an ethanol-contg. atmos. and observing any colour change in an ethanol-sensitive test strip located within the mask. Pref. the test strip comprises an absorbent support impregnated with an alcohol oxidase, a peroxidase, a chromogen, a buffer, and opt. other additives. The chromogen may be o-tolidine, benzidine, o-dianisidine or 2,7-diaminofluorene. Such strips may be produced by impregnating conventional peroxide-sensitive test strips with an alcohol oxidase soln. ADVANTAGE - Ethanol has low toxicity, is easily vaporised in test chambers, and can be detected at concns. as low as 1 pt