Transcript Fit Testing Respiratory Protection in the US

Fit Testing of Respiratory
Protection in the US
European Section General Meeting
March 10, 2011
Geoff Betsinger, CIH
3M Company
Vice President, ISRP
Respiratory Use in the US Workplace
• An estimated 5 million workers are required to
wear respirators in 1.3 million workplaces
throughout the United States.
• US OSHA requires fit testing tight fitting
respirators as part of a respiratory protection
program.
• Respiratory protection standard is usually
always in the OSHA “Top 10 list” of cited
standards for violations every year
Protection Factor
• Protection Factor = Co / Ci
• Co = Concentration outside the respirator
• Ci = concentration inside the respirator
Fit Factor
• Fit Factor = Co / Ci
• Co = Concentration outside the respirator
during a quantitative fit test
• Ci = concentration inside the respirator during
a quantitative fit test
Workplace Protection Factor (WPF)
• A measure of protection provided
in the workplace, under the
conditions of that workplace, by a
properly selected, fit tested and
functioning respirator while it is
correctly used and worn.
Simulated Workplace Protection
Factor
• A surrogate measure of the
workplace protection provided by a
respirator, which is done in a
laboratory simulation which has
been shown to have a stated
correlation to workplace
protection factors.
History of Fit Testing Requirements in U.S.
• 1963 – Respiratory Protective Devices Manual, AIHA and
ACGIH 1963
– Introduced iso-amyl acetate fit test for gas and vapor
cartridges
– Stressed the importance of proper fit during training for
respirator use.
• 1969 - ANSI Z88.2-1969
– Adopted much of what was introduced by AIHA and ACGIH
regarding respirator fit.
– Introduced irritant smoke fit testing for high efficiency
particulate respirators
History of Fit Testing Requirements in U.S.
•
Since 1971, US Occupational Safety and Health Administration (29 Code of Federal
Regulations 1910.134) has mandated that fit testing be part of a Respiratory
Protection Program.
– 1971 - Adopted wording from ANSI Z88.2
– In 1998 OSHA published fit testing procedures and requirements for
respiratory protection program;
•
Selection
•
Medical evaluations
•
•
•
•
•
•
•
–
Fit-testing of tight-fitting respirators
Use
Maintenance
Air quality, quantity, and flow for atmosphere-supplying respirators
Training in respiratory hazards
Training in respirator use and maintenance
Evaluating program effectiveness
Employer provides respirators, training and medical evaluations at no cost
to employee
Fit Testing Requirements
• All tight-fitting respirators
• Positive pressure respirators
–
Fit test facepiece in negative pressure mode
Use filters with facepiece
• Use a surrogate
•
–
Either QLFT or QNFT
• QNFT minimum requirements
– 100 for half facepieces
– 500 for full facepieces
•
QNFT required for negative pressure full
facepiece if claiming APF > 10
Fit Testing Requirements
• Frequency
– Prior to initial use
– If a different make or size respirator is used
– Annually thereafter
– Change in employee’s physical condition affecting
fit
Acceptable Fit Test Methods
QLFT
QNFT
Half facepiece, neg. pressure
Yes
Yes
Full facepiece, neg. pressure, used up to
10 x PEL (Fit Factor <100)
Yes
Yes
Full facepiece, neg. pressure, used at
greater than 10 x PEL (Fit Factor >100)
No
Yes
Tight fitting facepieces used with PAPRs,
supplied air or SCBA
Loose fitting respirators (e.g. helmets,
hoods) or escape type respirators
Yes
Yes
Not
required
Not
required
Fit Test Protocols in appendix A
of 29 CFR 1910.134
• Qualitative fit testing
–
–
–
–
•
Isoamyl acetate
Saccharin solution aerosol
Irritant fume
Bitrex
Quantitative fit testing
– Generated aerosol
– Ambient aerosol (Portacount)
– Controlled negative pressure (now includes
REDON protocol)
History of APF
• Historically, Assigned Protection Factors in the US were
based on Fit Testing
– 1965 Bureau of Mines
• Half mask (10 X TLV) and full face respirators (100
X TLV)
• Based on quantitative fit testing
– 1975 NIOSH and OSHA published Respirator
Decision Logic with protection factors based on
quantitative fit test studies performed by Hyatt
(1975).12
– ANSI Z88.2-1980 contained the first ANSI Z88.2
Respiratory Protection Factor Table.
• Based mainly on fit test studies by Hyatt and gave
higher protection factors to Quantitatively fit
tested respirators
History of APF
• 1987 NIOSH revised RDL
– Lowered some APF based on WPF results
• e.g. PAPR with loose fitting reduced to 25
• 1992 ANSI revised Z88.2
– Changes based on WPF studies and lack of correlation
between Fit Factors and Workplace performance. 1
– Where WPF studies did not exist laboratory studies
and design analogies were used.
– Abandoned higher APF based on Quantitative Fit
Testing
History of OSHA APF Development
• 1998 OSHA published Final Respiratory
Protection Standard
– Did not include APF or Maximum Use
Concentration (MUC)
• 2004 NIOSH published Respiratory
Selection Logic with 1987 APF tables.
– NIOSH stated that when OSHA publishes
APF then NIOSH will consider revisions
• 2006 OSHA published APF table
• Today, NIOSH has not revised RSL
Health Care and TB Respiratory
Protection
• For several years this past decade Health Care in
the US was exempt from OSHA enforcement of fit
testing for respirators worn to reduce TB
exposure.
– Wicker amendment was added as a rider to the
appropriations bill which prevented money to be
spent on enforcement of fit testing for TB exposure.
– Strong push to enforce fit testing from Health and
Safety groups.
– Amendment was not added in 2008 and enforcement
resumed.
Arguments Against Fit Testing
• Biggest complaint regarding fit testing is that it is time
consuming and costly.
– Same argument for many health and safety policies
• Initiatives have been taken from academia and
industry.
– NIOSH No Fit Test Respirator Workshop 2008
• Explored technologies that could improve or abbreviate fit testing
and also technologies that could make fit testing not necessary
• Hosted by the University of Minnesota and final report can be
downloaded;
http://www.sph.umn.edu/ce/presentations/nofit.asp
– Nelson, T., Janssen, L., Development of an Abbreviated
Qualitative Fit Test Using Bitter Aerosol
– TSI Q Fit
Can Fit Factors’ Predict Workplace
Performance?
• Because Work Place Protection Factor studies
showed that Work Place Protection Factors and
Fit Factors are not equal, studies have been
performed in the US to try to find a correlation
between FF and WPF. Most have shown no
correlation or, at best, a weak correlation.(2-7)
– Best correlation expected to be where respirators are
poor fitting but since it is unethical to expose workers
that fail a respiratory fit test to concentrations
exceeding OELs it is difficult to perform a study.
– Additionally, aerosol size distribution in the workplace
is much different than in fit test protocols
Does Fit Testing Increase Work Place
Protection?
• Absolutely!
• Studies have demonstrated that when fit testing is performed work place
protection provided to the respirator wearer is increased.
– Centers for Disease Control. Morbidity and mortality Weekly Report
1998/47(48):1045-1049. -“The findings in this report indicate that fit testing
N95 respirators is essential in programs employing these respirators and can
eliminate poorly fitting respirators, ensuring at least the expected level of
protection.”
– Zhuang et. al. – “…study supported the relevance of fit-testing as part of a
respirator program.”6
– Coffey et. al. – “The study also supports the value of some fit-test methods as
a screening tool to identify workers with poorly fitting respirators.”4
• In 1999, Colton compared WPF studies performed in Europe that did not
require fit testing to WPF studies performed in the US that did require fit
testing.
– When WPF included fit testing the 5th percentile WPF was 25-30.
– When fit testing was not performed the 5th percentile WPF was 2.1
WPF Studies and Fit Testing
Colton 3M JHH 199911
Does Fit Testing Increase Work Place
Protection?
• More recently, Lee et. al.8 and Reponen et. al.9
demonstrated increased protection factors
with ‘good fit versus poor fit’.
“Protection Factors” of subject in NaCl chamber (includes both filter
penetration and face seal leakage)
Summary and Conclusions
• Since 1971, OSHA has required and enforced
fit testing of tight fitting respiratory protection
in the US.
• When fit testing is performed as part of a
complete Respiratory Protection Program the
wearer is better protected than when fit
testing is not performed.
Bibliography
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