ABSTRACT
The Occupational Safety and Health Act requires that employees shall be protected from breathing air containing hazardous concentrations of dust, fumes, mists, gases. Respiratory protection devices vary in design and their usage. Selection depends on the toxic substance that is in the breathing air. Respirators should be issued from a central area where they will be cleaned and maintained. The user of the respirator must be instructed and trained in the proper use and limitations of a respirator. Every respirator wearer needs to receive fitting instructions, including demonstrations and practice in how the respirator should be worn, how to adjust it, and how to determine if it fits properly. Combinations of hazardous substances in different physical states require an air-fed respirator. There are many possibilities in various workplaces where more than one air contaminant in different physical states may be found. A local exhaust ventilation system is used to carry off air contaminants by trapping the contaminants near its source.
