Personal Protective Equipment - Respiratory

摘要

Harmful exposures to airborne contaminants in industrial workplace cannot be completely eliminated by using various safe technologies and by adopting engineering control measures. Respiratory protective equipment are therefore, essentially required to be used or made available at the shop-floor in case the situation demands. Various types of respiratory protective devices are required depending upon the hazard potential which can be classified in four major groups, namely oxygen deficient atmosphere, gas or vapour contaminants, airborne particulate matter, and mixture of gases, vapours and particulate matter. The respiratory protective devices may be classified in two major groups - Air supplying respirators and air purifying respirators. Air supplying respirators or self contained breathing apparatus has no limitation as to the concentration of the gas or deficiency of oxygen in the surrounding atmosphere but other factors may limit the time that the wearer can remain in a contaminated atmosphere. Air purifying respirators are used when the type of the contaminant and its levels are known and never in oxygen deficient atmosphere. The canister gas mask/cartridge respirator is used for gases like chlorine, ammonia, hydrogen sulphide and organic vapours. Mechanical filter type respirators/dust mask is used for protection against airborne particulate matter. The quality of the personal protective equipment is ensured by subjecting it to various test parameters namely, breathing resistance (Inhalation and exhalation valves), face piece fitness, filtration efficiency of dust respirators, life and efficiency of the sorbents of canisters/cartridges, purity of the breathing air supplied through self contained breathing apparatus, etc. The Central Labour Institute has the facility for testing of the respiratory protective appliances. On the basis of the performance test report, it has been observed that the disposable dust mask manufactured by various industries are gradually improving in quality and conforming to the specification of BIS. In the year 1995, only 7% of the samples were found to conform IS:9473-1980 whereas gradual development in the quality showed that in the year 2000, 63% of the samples were conforming to the specification.