Taking a respirator fit test is a requisite before a person can use any type of tight-fitting respirator. The Occupational Safety and Health Administration (OSHA) requires the implementation of respirator fit testing in order to assess if the respirator face piece fits a person’s face properly.
A fit test is conducted to assess the seal between the respirator and the person’s face. The test would generally take around 15-20 minutes and should be conducted annually. The prevalent reason why this is crucial is because a tight-fitting respirator cannot provide any protection if it does not fit the person’s face and neck. Therefore, conducting a fit test prior to the use of these face piece is necessary.
A respirator fit test is different from a user seal check. These two are often used interchangeably, but it is important to know that these two are different. A user seal check is performed to check whether the face piece is properly worn or if there are any adjustment that needs to be done.
Quantitative Fit Test (QNFT)
A quantitative fit test or also known as QNFT is a type of fit test that uses an instrument in order to measure the leakage along the face seal and yield a numerical result for the assessment called the “fit factor.” There are three protocols that constitutes a quantitative fit test, and these are:
- Generated aerosol, which involves a non-hazardous aerosol (e.g. corn oil)
- Condensation nuclei counter (CNC), which involves the use of ambient aerosol
- Controlled negative pressure (CNP), which involves temporarily cutting the air off through the use of a vacuum
Qualitative Fit Test (QLFT)
On the other hand, a qualitative fit test or also known as QLFT may only be used to test air-purifying or negative pressure respirators, that are only used in environments where the hazard is ten times less than what is allowed or the permissible exposure limit or PEL
Qualitative fit test can also be used for tight-fitting face pieces that involves atmosphere supplying and powered respirators. Listed below are the exercises performed for this method:
- deep breathing
- normal breathing
- moving head up & down
- moving head side to side
Importance of Respirator Fit Test
Respirator fit test ensures that the tight-fitting face piece properly fits and adheres with the person’s face in order to provide its maximum protection. The primary importance of respirator fit test are to:
- ensure the seal of the tight-fitting face piece
- check the compatibility along with other PPEs
- determine the respirator’s ability to maintain its seal