a. Nature of Hazard. Identify the substance or substances against which
protection is required. Determine the hazards and significant properties of each
substance. Determine the physical state in which the contaminant is likely to occur. Is
the hazard one of oxygen deficiency, or is it dangerous to life and health? This is the
first and over riding consideration.
b. Conditions of Exposure. Determine the conditions of exposure, the
potential exposure, and the reliable exposure (determines the TWA) present. What is
the location of the hazard? What will be the duration of the exposure?
c. Safety Requirements. What are the specific requirements for protection of
the eyes, face, and so forth? Are there human capabilities that are essential to the safe use of
d. Movement Required. What is the range of worker movement necessary for
accomplishment on the job? What are the entry and exit (egress) requirements?
e. Decision Logic. Appendix F contains a guide for selection of respirators.
NOTE: There is one limitation that should be kept in mind, as it affects all respiratory
protective devices: Certain gases can harm the body by means other than through the
respiratory tract. For example, ammonia, in a sufficiently high concentration, can cause
skin burns, particularly on moist skin. As a result, suitable protective clothing would
have to be worn, in addition to the proper respirator.
2-23. INSTRUCTION IN RESPIRATOR USE
If respirators are to be safely used, the workers must be thoroughly instructed
and trained in their selection, use, and maintenance. Both workers and supervisor must
be trained, and only persons fully competent in the use of the devices should be allowed
to conduct the training. As a minimum, the training must include:
a. Instruction in the nature of the hazard, along with an honest appraisal of the
consequences if the respirator is not used.
b. Explanation of why the respirator is needed and why it is not possible to
employ more positive control in the work area. Worker acceptance will be enhanced if
there is recognition that every reasonable effort is being made to reduce or eliminate the
need for respirators.
c. Explanation of the basis for selection of the particular respirator. The training
must include instructions covering the fitting of respirator on personnel with special
problems, such as facial hair, eyeglasses, deep cuts, scars, or irregular facial features
(for example, hollow temples, dentures, lack of teeth, and so forth.).