Monthly Round Up of Important Ideas and Standards in
Industrial Hygiene and Safety
IN THIS ISSUE: Testing Respirator Fit
To be effective, respirators must fit properly. Only then can they reduce the wearer’s exposure to the contaminant for which it is designed to protect. This includes when the respirator is initially issued and fit tested and when the user wears the respirator out in the field. Failure to ensure proper fit can make the respirator ineffective and give the wearer a false sense of security.
Tight fitting respirators include half- or full-facepiece or dust masks. They have a seal around the face that must be maintained at all times. Facepiece respirators may include SCBA, airline, or those with filter canisters.
When providing a respirator, it is crucial that both issuer and user know the following:
- Contaminants the user may be exposed to and what controls are available to provide protection (i.e ventilation
- What affects and concentrations of those chemicals for which the user will be exposed
- At which concentrations are the respirator designed to protect
- Conditions when a respirator should be used
- How to conduct a seal check anytime the respirator is used
- Is the user medically qualified to use a respirator
- How to inspect, don, clean, and maintain a respirator
If all of these items are satisfied, an employee can be fit tested and provided with a respirator(s).
There are two types of fit tests:
Qualitative fit testing uses the sense of taste or smell or reaction to an irritant in order to detect leakage into the respirator facepiece. It does not measure the actual amount of leakage. Whether the respirator passes or fails the test is based simply on the user detecting leakage of the test substance into the facepiece. There are four qualitative fit test methods accepted by OSHA:
- Isoamyl acetate: smells like bananas
- Saccharin: leaves a sweet taste in the mouth
- Bitter: leaves a bitter taste in your mouth
- Irritant smoke: may cause coughing
Quantitative fit testing uses a machine to measure the actual amount of leakage into the facepiece and does not rely on sense of taste, smell, or irritation in order to detect leakage. The respirators used during this type of fit testing will have a probe attached to the facepiece that will be connected to the machine by a hose. There are three quantitative fit test methods accepted by OSHA:
- Generated aerosol
- Ambient aerosol
- Controlled negative pressure
There are advantages and disadvantages for both types of testing. Qualitative fit testing should only be used on half face N95 or elastomer respirators while quantitative fit testing can be used for any type of tight fitting respirator. Qualitative fit testing can be used on the wearer’s respirator while a quantitative test is done on a respirator with a probe.
Other important points:
- Prescription glasses, safety goggles or earmuffs used while performing a job should be worn during the test to simulate actual work conditions.
- Facial hair, such as a beard or mustache, can affect a respirator’s ability to protect and must not be worn during the test or when a respirator is used.
- If the user fails the test or the fit becomes unacceptable, different types of respirator should be available. The selection may include a new make, model, style, or size of respirator.
See 1910.134 Appendix A for specific OSHA requirements.
For more information on this topic and to discuss your company’s safety and industrial hygiene needs call OccuSafe at (214) 662-6005 or visit us at www.occusafeinc.com.
OccuSafe Industrial Hygiene & Safety, Inc. provides skills and expertise to recognize, evaluate and control hazards and injuries in the areas of industrial hygiene, occupational safety and health. OccuSafe services companies of all sizes in a range of industries.
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