Page 25 - PPE GUIDELINE

Guidelines on the Use of PPE Against Chemical Hazards

For qualitative fit testing, banana oil (isoamyl acetate) testing agent can be used only
for those respirator equipped with organic vapour cartridges. Saccharin and Bitrex test
agents are used for testing particulate dust respirators and irritant smoke test agent
should be used only with high efficiency filters such as P100 filter.

Quantitative Fit Test

For quantitative fit test, a special quantitative fit testing equipment and a trained
technician (by manufacturer) is required.

Note: If a quantitative fit test is used for negative-pressure respirator, a fit factor
that is at least 10 times greater than the assigned protection factor shall be
obtained before that respirator can be assigned to the user. For positive-
pressure respirators, a fit factor of at least 100 must be obtained.

Refer to the US Occupational Safety and Health Administration -Accepted Fit Test
Protocols for details of the qualitative fit-test protocols and the quantitative fit-test
protocols.

Use

Follow the manufacturers’ instructions and limitations on the use of respirators. For
respiratory protection to be effective to keep all contaminants out of worker’s air
intake, they must be worn for 99% of the time in the hazardous environment. Not
wearing a respirator for short periods while it is needed could have a profound effect
on overall protection. While a respirator is not worn, the protection factor it provides
is 1 (i.e. the individual is exposed to the ambient contaminant concentration). The
effective protection factor (EPF) can be calculated from the following equation (The
Occupational Environment-Its Evaluation & Control):

EPF = Work time requiring respirator use in minutes
(1/APF)(Wear time in minutes) + Non wear time in minutes

For example, if a person removes his or her respirator for 1 minute to talk during a
task that takes 1 hour, the wear time is 59 minutes or 98% of the task duration. If the
person uses a respirator with a level of protection of 1000, the effective level of
protection actually achieved is 56! As non-wear time increases for any respirator, the
protection levels for all respirators approach 1. Hence, respirators must be worn
continuously throughout the time when the risk or risks are present. Refer to
Figure 2 below for comparison of effective protection versus percentage of time worn
for half-mask and full face-piece respirators and SCBA.

Department of Occupational Safety & Health, Ministry of Human Resources, Malaysia ™October 2005 25