© 2007, TSI Incorporated

Health and Safety Products

An Introduction to Respirator Fit Testing

Gregory M. Olson, Jr. MSGregory M. Olson, Jr. MSSr. Industrial HygienistSr. Industrial Hygienist

Product Manager – Health and Safety Product Manager – Health and Safety TSI IncorporatedTSI IncorporatedSeptember 2008September 2008

greg.olson@tsi.comgreg.olson@tsi.com

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Purpose

• To introduce you to the practicalities of, types of, and justification for Fit Testing

• To introduce Qualitative and Quantitative Fit Testing

• To establish the applicability of Fit Testing and it’s limitations

© 2007, TSI Incorporated

Why do people wear respirators?

• Their workplace cannot be certified as safe• Therefore toxic materials are, or could be,

present• Well fitted respirators will protect against harm• But will only reduce, not eliminate exposure• Respirators are not universally guaranteed and

how well they are managed will have a direct effect on how well they deliver protection

• Fit Testing validates that protection

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What is Fit Testing?

• Fit Testing assesses the efficiency of tight fitting respiratory protection and the level of protection routinely achieved in the work place

• Fit Testing establishes the relationship between assigned protection factors and workplace protection factors in the field

• Fit Testing is a training tool that will deliver better protection

• Fit Testing can be subjective or objective

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Why Fit Test?

• All respirators leak

• Good respirators only leak very little so very sensitive test methods are needed

• Mainly between the face and the respirator

• Trained staff achieve better protection

• Training is more effective when validated by testing

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What will affect achieved level of protection?

• Selection: How well suited is the type and the size of respirator to the person who will wear it and the hazard it is to reduce?

• Fitting: How appropriate is the correct size of mask selected and how might that have changed since the respirator was first issued?

• Donning: How well has the wearer been trained and remembered how to put the respirator on properly?

• Training: How well has the wearer been trained to look after and maintain the respirator so it continues to offer the required level of protection?

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Tight Fitting Respirators

• Fit Testing can be used to assess all tight fitting respiratory protection such as

– Disposable filtering face pieces– Elastomeric half face respirators– Elastomeric Full face respirators– Positive-pressure, pressure-demand breathing

apparatuses• SCBA’s• Air-line systems• PAPR’s

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What is a Fit Factor?

• Fit Factor is the ratio between the concentration of some material inside the mask compared to the concentration of the same material outside the mask. The higher the fit factor the higher the level of protection that is achieved

Fit Factor (FF) = Concentration Outside Mask

Concentration Inside Mask

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The two ways to measure Fit Factor

• Qualitative– Is a subjective test that requires the wearer to state when

they can detect, either by taste or by smell, the presence of a test agent deliberately introduced into a chamber or hood that the test subject enters wearing their respirator

– Must be done after the current sensitivity of the test subject to the test agent has been measured

– Can only be used at FF<100 because the test has never been validated against higher Fit Factors

– Introduces an element of perceived risk to the test subject– Can be cheated

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The two ways to measure Fit Factor

• Quantitative– Is an objective test that actually uses a calibrated device to

measure the concentration of a material inside and outside of the respirator in real time during a series of exercises designed to approximate conditions of respirator use and to test various aspects of the respirators dynamic performance

– Does not involve the test subject in any part of the pass fail decision

– Has been validated and can be used at FF up to 100,000– Can automatically document the entire test procedure and

result ensuring complete recorkeeping

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Qualitative Fit Testing

• Challenge agents– Saccharin– Bitrex– Isoamyl acetate (banana oil)– Irritant smoke

• Process– Sensitivity test (5 – 10 min)– Wait (to reset sensitivit, 15 min)– Carry out Fit Test (15 – 30 min)– Wearer defines pass/ fail

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Quantitative Fit Testing

• Uses ultrafine particles in ambient air

• Process– Don and breathe mask down (2 -

3 min)– Carry out Fit Test (3.5 - 10 min)– Automatically calculates FF from

fit test results– Compare FF with pass fail criteria– All automatic, no interpretation, no

human error

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Test ProtocolsDesigned to stress and test face seal fit under workplace conditionsTypically:1. Normal breathing- at rest2. Deep breathing – with moderate exercise3. Head moving up and down4. Head moving side to side5. Talking 6. Grimace7. Bending over8. Normal Breathing – at rest

Each exercise lasts anywhere from 30 to 86 seconds, depending on QNFT protocol used

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Quantitative Fit Test Protocol Using PortaCount

0

2000

4000

6000

8000

10000

12000

Exercise 1

Exercise 2

Exercise 3

Exercise 4

Exercise 5

Exercise 6

Ambient sample

In mask sample

PassPass PassPass PassPass PassPass PassPass FailFail

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Summary

• Fit Testing improves training, which improves protection

• Qualitative testing is subjective, time consuming and open to abuse

• Quantitative testing is objective, documented, reproducible and not open to abuse

• Fit Testing closes the loop on the supply and use of RPE

© 2007, TSI Incorporated

Thank you