Federal Registers - Table of Contents Federal Registers - Table of Contents
• Publication Date: 06/25/2009
• Publication Type: Proposed Rules
• Fed Register #: 74:30250-30256
• Standard Number: 1910
• Title: Abbreviated Bitrex® Qualitative Fit-Testing Protocol

[Federal Register: June 25, 2009 (Volume 74, Number 121)]
[Proposed Rules]               
[Page 30250-30256]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25jn09-20]                         

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DEPARTMENT OF LABOR

Occupational Safety and Health Administration

29 CFR Part 1910

[Docket No. OSHA-2007-0006]
RIN 1218-AC29

 
Abbreviated Bitrex® Qualitative Fit-Testing Protocol

AGENCY: Occupational Safety and Health Administration (OSHA); Labor.

ACTION: Proposed rule; withdrawal.

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SUMMARY: After thoroughly reviewing the comments and other information 
available in the record for the proposed rulemaking, OSHA decided that 
the abbreviated Bitrex® qualitative fit test is not sufficiently 
accurate to include among the qualitative fits tests listed in Part II 
of Appendix A of its Respiratory Protection Standard. Therefore, OSHA 
is withdrawing the proposed rule without prejudice, and is inviting 
resubmission of the proposed fit test after conducting further research 
to improve the accuracy of the protocol.

DATES: Effective June 25, 2009, the proposed rule published December 
26, 2007 (72 FR 72971) is withdrawn.

FOR FURTHER INFORMATION CONTACT: General information and press 
inquiries: Contact Ms. Jennifer Ashley, Office of Communications, Room 
N-3647, OSHA, U.S. Department of Labor, 200 Constitution Avenue, NW., 
Washington, DC 20210; telephone (202) 693-1999.
    Technical inquiries: Contact Mr. John E. Steelnack, Directorate of 
Standards and Guidance, Room N-3718, OSHA, U.S. Department of Labor, 
200 Constitution Avenue, NW., Washington, DC 20210; telephone: (202) 
693-2289; facsimile: (202) 693-1678. Electronic copies of this Federal 
Register notice, as well as news releases and other relevant documents, 
are available at OSHA's Web page at http://www.osha.gov.

SUPPLEMENTARY INFORMATION:

I. Background

    Part I to Appendix A of OSHA's Respiratory Protection Standard at 
29 CFR 1910.134 currently includes four qualitative fit-testing 
protocols using the following challenge agents: Isoamyl acetate; 
saccharin-solution aerosol; Bitrex® (denatonium benzoate) 
aerosol in solution; and irritant smoke (stannic chloride). Part II to 
Appendix A specifies the procedure by which OSHA determines whether to 
propose adding a new fit-testing protocol to the Respiratory Protection 
Standard. The criteria used in making this determination include: (1) A 
test report prepared by an independent government research laboratory 
(e.g., Lawrence Livermore National Laboratory, Los Alamos National 
Laboratory, the National Institute for Standards and Technology) 
stating that the laboratory tested the protocol and found it to be 
accurate and reliable; or (2) an article published in a peer-reviewed 
industrial-hygiene journal describing the protocol and explaining how 
the test data support the protocol's accuracy and reliability. If a 
fit-testing protocol meets one of these criteria, OSHA must initiate 
notice-and-comment rulemaking on the proposed fit-testing protocol 
under Section 6(b)(7) of the Occupational Safety and Health Act of 1970 
(29 U.S.C. 655).

II. Summary and Explanation of the Withdrawal Notice

A. Introduction

    In the letter submitting the abbreviated Bitrex® qualitative 
fit-testing (ABQLFT) protocol for review under the provisions of 
Appendix A of OSHA's Respiratory Protection Standard (Ex. OSHA-2007-
0006-0002), Dr. Michael L. Runge of the 3M Company included a copy of a 
peer-reviewed article from an industrial-hygiene journal describing the 
accuracy and reliability of the ABQLFT protocol (Ex. OSHA-2007-0006-
0003). This article also described in detail the equipment and 
procedures required to administer the ABQLFT protocol. According to 
this description, the protocol is a variation of the existing 
Bitrex® qualitative fit-testing protocol developed by the 3M 
Company in the early 1990s, which OSHA approved for inclusion in the 
final Respiratory Protection Standard. The ABQLFT protocol uses the 
same fit-testing requirements and instrumentation specified for the 
existing Bitrex® qualitative fit-testing protocol in paragraphs 
(a) and (b) of Part I.B.4 of Appendix A of the Respiratory Protection 
Standard, with the following two exceptions:
     Exercise times are reduced from 60 seconds to 15 seconds; 
and
     The ABQLFT protocol is used only with test subjects who 
can taste the Bitrex® screening solution within the first 10 
squeezes of the nebulizer bulb (referred to as "Level 1 
sensitivity").
    The peer-reviewed article submitted by the 3M Company describing 
the study conducted on the ABQLFT, entitled "Development of an 
Abbreviated Qualitative Fit Test Using Bitter Aerosol," appeared in 
the Fall/Winter 2003 issue of the Journal of the International Society 
for Respiratory Protection (hereafter, "the ABQLFT study" or "the 
study"; Ex. OSHA-2007-0006-0003). The authors of the study were T.J. 
Nelson of NIHS, Inc., and L.L. Janssen, M.D. Luinenburg, and H.E. 
Mullins of the 3M Company; the 3M Company supported the study. The 
study described by the article determined whether performing a fit test 
involving seven exercises lasting 15 seconds each while exposed to 
Bitrex® solution aerosol yielded fit-testing results similar to 
results obtained with a generated-aerosol (i.e., corn oil) quantitative 
fit test (GAQNFT) using one-minute exercises (i.e., the GAQNFT was the 
criterion measure or "gold standard").
    The study involved 43 experienced respirator users, 20 females and 
23 males. The test subjects followed the existing Bitrex® 
qualitative fit-testing protocol in Appendix A of OSHA's Respiratory 
Protection Standard except that they performed each of the fit-testing 
exercises for 15 seconds (instead of 60 seconds) while wearing a NIOSH-
certified elastomeric half-mask respirator equipped with P100 filters. 
The authors selected the best fitting respirator for each test subject 
from among four models, each available in three sizes; some test 
subjects used more than one model during fit testing. In addition, the 
authors induced poor respirator fits by assigning a respirator to test 
subjects that was one or two sizes too small or too large as determined 
by the Los Alamos National Laboratory panel-grid size and observation 
of the test subjects' facial characteristics. Test subjects could 
adjust the respirator facepiece for comfort, but they did not perform 
user seal checks.
    In conducting the study, the authors used the recommendations for 
evaluating new fit-test methods specified by Annex A2 of ANSI Z88.10-
2001, including sequencing the ABQLFT and GAQNFT in random order 
without disturbing facepiece fit. The authors used fit-test sample 
adaptors or respirators with fixed probes to collect samples inside the 
respirator. The sample point inside the respirator was located between 
the nose and the mouth. For both fit tests, the authors had the test 
subjects perform seven of the eight exercises listed in Part I.A.14 of 
Appendix A of OSHA's Respiratory Protection Standard, which included: 
Normal breathing, deep breathing, turning the head side to side, moving 
the head up and down, reading a passage, bending over, and normal 
breathing.\1\ For the GAQNFT, the authors performed particle counts at 
one-second intervals inside a test chamber for 15-30 seconds before and 
after fit testing, and inside the respirator for the 60-second duration 
of each exercise.
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    \1\ The test subjects did not perform the grimace exercise.
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    The 43 test subjects used in the study had Level 1 sensitivity to 
Bitrex® because they were able to taste the Bitrex® 
aerosol within 10 squeezes of the nebulizer bulb. Subjects having Level 
2 or 3 sensitivity to Bitrex® were excluded from further 
participation in the study because the nebulizer could not be 
replenished for additional taste testing within the 15 seconds allotted 
to perform each fit-testing exercise. After the test subjects passed a 
Bitrex® sensitivity-screening test, the authors administered the 
ABQLFT using the procedures and techniques specified for the existing 
Bitrex® qualitative fit-testing protocol in Part I.B.14 of 
Appendix A of OSHA's Respiratory Protection Standard, and determined 
the fit factor using the particle count for the 15-second duration of 
each exercise.
    The authors required a fit factor of 100 to pass a fit test, which 
served as the basis for determining the following statistics for the 
ABQLFT: Test sensitivity; predictive value of a pass; test specificity; 
and predictive value of a fail. In calculating these statistics, the 
authors adopted the variables defined by ANSI Z88.10-2001, in which: A 
= false positives (passed the fit test with a fit factor < 100); B = 
true positives (passed the fit test with a fit factor >= 100); C = true 
negatives (failed the fit test with a fit factor < 100); and D = false 
negatives (failed the fit test with a fit factor >= 100). Using these 
variables, ANSI Z88.10-2001 specifies the formula and recommended value 
(RV) for each statistic as follows: Test sensitivity = C/(A + C), RV >= 
0.95; predictive value of a pass = B/(A + B), RV >= 0.95; test 
specificity = B/(B + D), RV > 0.50; and predictive value of a fail = C/
(C + D), RV > 0.50.
    Using the GAQNFT as the criterion measure, the variables for the 
ABQLFT had the following values: A = 4; B = 95; C = 48; and D = 20. The 
statistics calculated for the ABQLFT from these values were: Test 
sensitivity = 0.92; predictive value of a pass = 0.96; test specificity 
= 0.83; and predictive value of a fail = 0.71. Therefore, every 
statistic for the ABQLFT, except test sensitivity, attained a value in 
excess of the ANSI Z88.10-2001 recommended value.
    The test-sensitivity value of 0.92 for the ABQLFT fell below the 
ANSI recommended value of 0.95. The authors state that this slight 
difference represents a single false positive value for the ABQLFT 
(i.e., failed the GAQNFT but passed the ABQLFT). However, an additional 
peer-reviewed article submitted by Dr. Runge of the 3M Company suggests 
an alternative approach to examining these test-sensitivity values (see 
Ex. OSHA-2007-0006-0004). This article, entitled "Recommendations for 
the Acceptance Criteria for New Fit Test Methods" and published in the 
Spring/Summer 2004 issue of the Journal of the International Society 
for Respiratory Protection, describes an analytical study conducted by 
T. J. Nelson of NIHS, Inc. and H. Mullins of the 3M Company, and 
supported by the 3M Company. In this study, the authors performed a 
binary logistic-regression analysis on pass-fail fit-testing data from 
published studies involving two quantitative, and two qualitative, fit 
tests. The authors justify using the binary logistic-regression 
analysis for this purpose as follows:

    When a simple sensitivity test is used to describe a new test, 
the result can be affected by the distribution of the data. In 
several cases using the theoretical distributions described in this 
paper, the outcome of a sensitivity test for the Bitrex and Ambient 
Particle Counter fit tests could have failed to meet the ANSI Z88.10 
sensitivity requirement. The method used to determine acceptability 
should be independent of specific data collected. (See Ex. OSHA-
2007-0006-0004, p. 8.)

    The results of the binary logistic-regression analysis performed on 
the ABQLFT data showed that the ABQLFT had a 0.20 probability of 
passing a respirator user with a fit factor of 50 and a 0.33 
probability of passing a respirator user with a fit factor of 100. 
Figure 3 of the article compares the binary logistic-regression 
analysis results of test-sensitivity values obtained for a popular 
quantitative fit test and the existing 60-second Bitrex® 
qualitative fit test. The authors conclude that the analysis 
demonstrates that the distribution of fit-testing data affected the 
test-sensitivity values derived using the ANSI Z88.10-2001 test-
sensitivity calculations. Based on this analysis, the authors assert 
that "a sensitivity calculation may not be the best indicator of fit 
test method performance. The binary logistic regression analysis shows 
that the result of the 15 second exercise time test is very similar to 
the ambient aerosol and 60 second bitter aerosol tests" (Ex. OSHA-
2007-0006-0003, p. 108). In summarizing the results, the authors state 
that "[t]he 15 second bitter aerosol protocol sufficiently screens for 
adequate respirator fit in subjects with Level 1 Bitrex taste 
sensitivity."
    After carefully reviewing the peer-reviewed articles submitted in 
support of the ABQLFT, OSHA determined that the protocol met the second 
criterion specified in Appendix A of the Respiratory Protection 
Standard, and then developed a proposal to add a new fit-testing 
protocol to the standard. OSHA published the proposal in the Federal 
Register on December 26, 2007 (see 72 FR 72971).

B. Issues Raised for Public Comment

    In the Federal Register notice announcing the proposal, OSHA 
invited comments and data from the public regarding the accuracy and 
reliability of the proposed ABQLFT protocol, its effectiveness in 
detecting respirator leakage, and its usefulness in selecting 
respirators that will protect employees from airborne contaminants in 
the workplace. Specifically, the Agency invited public comment on the 
following issues:
     Were the studies described in the submitted articles well 
controlled, and conducted according to accepted experimental design 
practices and principles?
     Were the results of the studies described in the submitted 
articles properly, fully, and fairly presented and interpreted?
     Will the proposed ABQLFT protocol generate reproducible 
fit-testing results, and what additional experiments or analyses of 
existing data are necessary to answer this question?
     Will the proposed ABQLFT protocol reliably identify 
respirators with unacceptable fit as effectively as the qualitative 
fit-testing protocols, including the existing Bitrex® 
qualitative fit-testing protocol, already listed in Part I.B of 
Appendix A of the Respiratory Protection Standard?
     What is the significance of the test-sensitivity value of 
0.92 obtained for the ABQLFT relative to the test-sensitivity value of 
0.95 recommended by ANSI Z88.10-2001, and does the authors' assertion 
that "a sensitivity calculation may not be the best indicator of fit 
test method performance" adequately account for the lower test-
sensitivity value?
     What is the significance of limiting the ABQLT to 
respirator users who demonstrate Level 1 sensitivity to Bitrex®?

C. Summary of the Public Comments Received

    Twenty-two commenters submitted responses to the proposal. The 
following paragraphs in this section address the responses made to each 
of the six issues described previously, as well as additional issues 
addressed by the commenters themselves.
    1. Were the studies described in the submitted articles well 
controlled, and conducted according to accepted experimental design 
practices and principles? In addressing this issue, NIOSH stated:

    The primary journal article cited, Development of an Abbreviated 
Qualitative Fit Test Using Bitter Aerosol by Nelson et al. [2003], 
does not provide sufficient detail about the study design and 
protocol to enable a complete assessment of how well it was 
controlled and conducted. The description in the article does 
indicate that design and principles met acceptable practices. (See 
Ex. OSHA-2007-0006-0026.)

Jeff Weed asserted that the study did not exclude from the statistical 
analysis the fit factors used to determine the reference-method fit 
factors within one standard deviation of the required fit factor, a 
determination required under ANSI Z88.10-2001 (Ex. OSHA-2007-0006-
0020.1).
    Generally, the NIOSH comment appears to support the design 
practices and principles used in the study, and did not elaborate on 
what additional detail would "enable a complete assessment of how well 
[the study] was controlled and conducted." Jeff Weed's comment appears 
to be mistaken because page 104 of the article describing the study 
(see Ex. OSHA-2007-0006-0003) states that the "[f]ive fit factors 
within one standard deviation of the required fit factor of 100 (86 to 
114) were excluded from the data analysis as recommended by Z88.10." 
Therefore, OSHA concludes that the study was well controlled, and 
conducted according to accepted experimental design practices and 
principles.
    2. Were the results of the studies described in the submitted 
articles properly, fully, and fairly presented and interpreted? NIOSH 
made the following comments regarding this issue:

    NIOSH is concerned that the interpretation of the study results 
does not appropriately represent the performance of the fit testing 
protocol. The authors correctly stated that a shortened bitter 
aerosol fit test method relies on two assumptions: (1) Fit does not 
significantly change during an exercise and (2) people being tested 
will respond to the bitter taste of Bitrex® in the shorter 
time period. The results of the study support the second assumption, 
i.e., the test subjects classified with Level 1 sensitivity 
responded to the bitter taste of Bitrex® in the shorter time 
period. However, the study results do not provide convincing 
evidence to support the first assumption. * * *
    The consistency of the respirator's fit throughout each of seven 
exercises is important in the assessment of the performance of the 
ABQLFT fit test protocol. The fit factor assigned for each ABQLFT 
exercise in the study is based on a 15-second increment, in contrast 
to a 60-second increment for each of the same exercises performed in 
quantitative fit test (GAQNFT) protocol. Change in fit during an 
exercise suggests that the fit at the start of the next 60-second 
exercise in the GAQNFT is more likely to differ from the fit at the 
start of the corresponding 15-second exercise period of the ABQLFT. 
There is no indication that the authors considered the significance 
of the noted changes in fit on the accuracy of the assigned fit 
factors. (See Ex. OSHA-2007-0006-0026.)

Pages 104, 105, and 107 of the article describing the study (see Ex. 
OSHA-2007-0006-0003) addressed NIOSH's concerns about the variability 
of respirator fit for the 15-second and 60-second exercise periods, at 
least for the GAQNFT. Page 104 of the article states that the 
correlation between fit factors assessed for the two exercise periods 
was highly significant, with r = 0.97, while the text and figure on 
page 108 of the article note that variability was low for fit factors 
less than 100 and over 6,000. These results demonstrate convincingly 
that respirator fit factors, especially for fit factors in the range of 
interest (i.e., having values at and below 100), were reasonably 
consistent and stable across the 15-second and 60-second exercise 
periods.
    Jeff Weed commented (see Ex. OSHA-2007-0006-0020.1) that the study 
did not report a Kappa value, which ANSI Z88.10-2001 defines as the 
"statistic (K) used to calculate some degree of agreement between two 
fit tests"; the ANSI standard recommends a minimum Kappa value greater 
than 0.70. Based on the equation for the Kappa statistic provided in 
Annex A2 of the ANSI standard, Mr. Weed calculated the Kappa value for 
the study data as 0.69, which corresponds closely to our calculation of 
0.70, rounded from a figure of 0.69565. OSHA concludes, that the Kappa 
value calculated from the study data indicates an acceptable degree of 
agreement between the two fit tests used in the study, and conforms 
satisfactorily with the value recommended by the ANSI standard.
    3. Will the proposed ABQLFT protocol generate reproducible fit-
testing results, and what additional experiments or analyses of 
existing data are necessary to answer this question? NIOSH questioned 
the reproducibility of the fit-testing results, stating:

    Based on review of Nelson et al. [2003] and Nelson and Mullins 
[2004], NIOSH concludes that the evidence is inadequate to 
demonstrate reproducible fit testing results. Further investigation 
is required to compare potential changes in fit across the proposed 
15-second exercise intervals in the ABQLFT protocol and the standard 
60 second exercise intervals in the GAQNFT protocol. At a minimum, 
the frequency and consistency of leaks during each exercise, as well 
as the magnitude and type of those leaks (e.g. start of exercise, 
end of exercise, throughout exercise period) need to be identified 
and analyzed. (See Ex. OSHA-2007-0006-0026.)

OSHA addressed NIOSH's concern regarding the variability of respirator 
fit for the 15-second and 60-second exercise periods above (see item 
C.2 of this section).
    Jeff Weed questioned whether employers could reproduce the results 
of the ABQLFT study in the workplace, stating:

    When qualitative fit test (QLFT) methods such as the ABQLFT are 
performed in a laboratory by researchers, the results are reasonably 
reproducible. Researchers are keenly aware of the potential mistakes 
that cause variability, such as the manner in which the nebulizer bulb 
is squeezed (e.g. fully vs. partly, with the palm vs. the fingers, slowly 
vs. quickly). The way the nebulizer is used has a significant affect on 
the mass of agent that is injected into the fit test hood. Unfortunately, 
studies such as the one by Nelson do not take the practicality of the fit 
test method into account, when implemented by lay-persons. (See Ex. OSHA-2007-
0006-0020.1.)

The authors of the ABQLFT study mention on page 103 of the article 
describing the study (see Ex. OSHA-2007-0006-0003) that "[t]he bitter 
aerosol fit test followed the procedure outlined in the OSHA respirator 
standard, except that a 15 second exercise period was used." Section 
B.4 of Part I in Appendix A of that standard describes in elaborate 
detail how to administer properly the Bitrex® solution aerosol 
using the nebulizer bulb. OSHA holds that this description of the 
procedure is adequate, and that employers are responsible for complying 
fully with the procedure as described in OSHA's Respiratory Protection 
Standard. In addition, Mr. Weed's comment appears to be speculative in 
that he provided no evidence to support it.
    Ching-tsen Bien mentioned that "[t]here is only one repeated test 
on the same test subject with a standard deviation of 14" (Ex. OSHA-
2007-0006-0017.1). In a response to Mr. Bien, Robert A. Weber of 3M 
stated (see Ex. OSHA-2007-0006-0021.1) that Mr. Bien's comment 
describes the requirement specified in Annex A2 of ANSI Z88.10-2001. 
Mr. Weber quotes this requirement from Annex A2 as follows: "One 
standard deviation for the reference method can be approximated by 
identifying a subject having a fit factor near the required fit factor 
and making measurements on this subject during a single mask donning to 
determine system reproducibility." OSHA believes that Mr. Weber's 
response appropriately addresses Mr. Bien's concern.
    4. Will the proposed ABQLFT protocol reliably identify respirators 
with unacceptable fit as effectively as the qualitative fit-testing 
protocols, including the existing Bitrex® qualitative fit-
testing protocol, already listed in Part I.B of Appendix A of the 
Respiratory Protection Standard? Pete Stafford of the Building and 
Construction Trades Department, AFL-CIO, questioned whether the 15-
second exercise periods prescribed by the proposed ABQLFT protocol were 
sufficient to challenge the face-to-facepiece seal, stating:

    In the abbreviated protocol, normal and deep breathing exercises 
would only allow four to five breaths in 15 seconds. Side to side 
and up and down exercises might only allow one cycle of each in 15 
seconds. The talking exercise would be difficult to accomplish, as 
the rainbow passage presents a variety of facial expressions, and 
could not be completed in the 15 second time frame." (See Ex. OSHA-
2007-0006-0024.)

NIOSH argued that with the aerosol concentration replenished only once 
every 30 seconds, the exercise occurring during the first 15 seconds of 
this 30-second period would be near the maximum aerosol concentration, 
while the exercise occurring during the last 15-second period would be 
near the minimum concentration that occurs after filtration removes 
much of the aerosol from the hood. NIOSH further noted:

    * * * [T]he 60-second exercise duration in the OSHA-accepted 
Bitrex® protocol would be conducted through two complete 30-
second concentration-cycles, whereas the 15-second exercises of the 
ABQLFT were conducted through only half of one. While the variation 
in the aerosol concentration during this procedure has not been 
documented, the fact that the replenishing amount is half the 
quantity to establish the appropriate test challenge (for a fit 
factor of at least 100) suggests that variability could 
significantly affect the results. In addition, the variability in 
subjects' ability to taste Bitrex® at reduced concentrations, 
and the impact on the pass/fail results, needs to be determined and 
analyzed. (See Ex. OSHA-2007-0006-0024.)

    OSHA finds that the comments submitted by both Pete Stafford and 
NIOSH did not adequately consider the effects the alleged deficiencies 
should have on the results of the ABQLFT study. Failure to adequately 
challenge the facepiece-to-face seal, and low levels of aerosol present 
during an exercise, should increase the number of false positives, but 
the study data show no such effect. Therefore, absent any supporting 
data or analyses, OSHA considers these comments to be speculative.
    A number of commenters stated that the proposed protocol would not 
reliably assess proper fit for filtering-facepiece respirators because 
the authors did not include these respirators in the study design. In 
this regard, NIOSH noted that "the submitted study did not include any 
filtering facepiece respirators. This type of respirator is commonly 
used and likely to be evaluated by the ABQLFT protocol. NIOSH 
encourages evaluation of filtering facepiece respirators before 
acceptance of the ABQLFT protocol" (Ex. OSHA-2007-0006-0026). Ching-
tsen Bien asserted that "the validation testing should be performed on 
a variety of shapes of N-95 filtering facepieces to ensure that this 
method would reject inadequate fits for respirators of this type" (Ex. 
OSHA-2007-0006-0017.2).
    OSHA received additional comments on this issue from Timothy 
Roberts, who stated, "Another major concern is that the primary 
article [Nelson, 2003] did not include filtering facepiece respirators 
as part of the tests. Filtering facepiece respirators are often tested 
with the Bitrex qualitative protocol and therefore, the data may not be 
representative of the adequacy of the ABQLFT proposal for this class of 
respirators" (Ex. OSHA-2007-0006-0022). James S. Johnson recommended 
further testing of filtering facepieces using the proposed ABQLFT 
protocol, noting, "A similar study (Article 1) needs to be done with 
filtering facepiece respirators to demonstrate acceptable performance 
is achieved with this type of half mask respirator" (Ex. OSHA-2007-
0006-0028).
    Robert Weber of 3M addressed the issue of testing filtering-
facepiece respirators in his comments (see Ex. OSHA-2007-0006-0021.1), 
stating, "It is not possible to use N95 filtering facepieces to 
validate a fit test with submicrometer particle QNFT," adding that 
"[i]t is an evaluation of facepiece[-]to-face seal only; filter 
penetration is not included. While filter penetration of submicrometer 
particles through N95 filters is small, it is not zero." Mr. Weber 
concludes, "The use of N95 [filtering-facepiece respirators] would 
therefore skew the data by increasing [false-negative] error, i.e. 
rejecting adequate fits."
    Contrary to Mr. Weber's comments, OSHA finds that testing N95 
filtering-facepiece respirators as recommended by the other commenters 
is not validation testing, but instead is testing that would 
demonstrate that the proposed ABQLFT protocol performs adequately with 
N95 filtering-facepiece respirators, even when filter penetration 
increases false-negative error. Therefore, OSHA could not approve using 
the proposed ABQLFT protocol for fit testing filtering-facepiece 
respirators absent appropriate results demonstrating that the proposed 
protocol adequately determines fit for these respirators.
    5. What is the significance of the test-sensitivity value of 0.92 
obtained for the ABQLFT relative to the test-sensitivity value of 0.95 
recommended by ANSI Z88.10-2001, and does the authors' assertion that 
"a sensitivity calculation may not be the best indicator of fit test 
method performance" adequately account for the lower test-sensitivity
value? In addressing the first part of this issue (i.e., the 
significance of the test-sensitivity value of 0.92), Jeff Weed stated, 
"[I]t should be noted that of the 5 ANSI criteria, test sensitivity is 
the only one that ANSI states `shall' be met. The others carry the 
`should' qualifier. In ANSI parlance (paragraph 1.3), the word `shall' 
implies a mandatory provision, and `should' is used for advisory 
provisions" (Ex. OSHA-2007-0006-0020.1). Similarly, Bill Kajola of the 
AFL-CIO stated recommended that OSHA withdraw the proposed rule because 
"the most important ANSI criterion for approving a new test method has 
not been achieved," and that "[t]he research paper used by 3M in 
support of its application for approval (Ex. OSHA-2007-0006-0003) 
acknowledges the failure of the 15 second Bitrex fit test protocol to 
achieve the ANSI test sensitivity of 0.95 or greater, a consensus 
criteria established by the respiratory protection community" (Ex. 
OSHA-2007-0006-0019.1). Timothy Roberts, Mark Haskew, and Ching-tsen 
Bien stated that failure to achieve the ANSI test-sensitivity criterion 
was sufficient justification for OSHA not to adopt the ABQLFT (see Exs. 
OSHA-2007-0006-0022, -0023, and 0017.2, respectively). NIOSH believed 
that the reduced sensitivity-test value demonstrated that the proposed 
ABQLFT protocol was defective, stating, "A sufficient number of 
subjects met fit testing requirements using the ABQLFT protocol and 
failed using the GAQNFT protocol," and that "[t]he sensitivity test 
is a critical criterion to ensure the rejection of inadequately fitting 
respirators" (Ex. OSHA-2007-0006-0026). NIOSH concluded that 
"[b]ecause the observed value of 0.92 is below the ANSI criterion of 
0.95, NIOSH considers the value unacceptable."
    In the article describing the ABQLFT study (see Ex. OSHA-2007-0006-
0003), the authors state that "[a]dvisory criteria for evaluating new 
fit test methods outlined in Annex A2 to ANSI Standard Z88.10-2001 were 
used. * * *" Therefore, the authors adopted the ANSI standard as the 
method by which to evaluate the results of the study, including the 
test-sensitivity criterion which, as stated above by Mr. Weed, is the 
only criterion in the ANSI standard that is mandatory. OSHA believes 
adopting the ANSI standard is appropriate because that standard 
represents the consensus of the industrial-hygiene community regarding 
the criteria to use in assessing fit-testing protocols. The comments 
described in the previous paragraph clearly demonstrate that the 
industrial-hygiene community generally supports using the ANSI standard 
for this purpose.
    In comments submitted to the record, Robert Weber of 3M noted that 
"there is little significance to the test sensitivity of 0.92 versus a 
criterion of 0.95" (Ex. OSHA-2007-0006-0021.1). On page 108 of the 
article describing the ABQLFT study (see Ex. OSHA-2007-0006-0003), the 
authors observe that "[t]he difference between a sensitivity of 0.92 
and a value greater than 0.95 in this comparison is one fit test where 
a person with a generated fit factor less than 100 passed the bitter 
aerosol fit test." Based on Table 1 in this article, the 0.95 
criterion would permit three false-positive test subjects out of 167 
subjects tested (i.e., 0.018% of the total subjects tested), while the 
obtained value of 0.92 resulted in four false-positive test subjects 
(i.e., 0.024% of the subjects tested).
    In the NIOSH-Bureau of Labor Statistics survey of respirator use 
cited in the proposal (NIOSH-BLS survey; Ex. 6-3, Docket H-049C), 
282,000 establishments in the United States required respirator use, 
and these establishments fit tested about 3.3 million employees each 
year. According to the NIOSH-BLS survey, 18,938 (0.067%) of these 
establishments used the existing Bitrex® qualitative fit-testing 
protocol.\2\ Assuming that these establishments would substitute the 
proposed ABQLFT protocol for the existing Bitrex® qualitative 
fit-testing protocol, and that the distribution of employees across 
size classes for these establishments is representative of the 
establishments as a whole,\3\ then 221,100 employees would receive the 
proposed ABQLFT protocol annually (i.e., 0.067% x 3.3 million 
employees).
---------------------------------------------------------------------------

    \2\ The proposal cited a figure of "approximately 25,000 
establishments," but this figure is for the original Controlled 
Negative Pressure quantitative fit-testing protocol specified by 
OSHA when it first published the Respiratory Protection Standard in 
1998, not for the existing Bitrex® qualitative fit-testing 
protocol.
    \3\ The term "size classes" refers to the number of employees 
in the establishments; the NIOSH-BLS survey designates these classes 
as follows: 1-10 employees; 11-19 employees; 11-49 employees; 50-249 
employees; 250-999 employees; and 1,000 and more employees. A 
cursory review of the size-class distribution in the NIOSH-BLS 
survey shows that 0.088% of the total number of establishments have 
1,000 or more employees, while 0.094% of establishments 
administering the existing Bitrex® qualitative fit-testing 
protocol have 1,000 or more employees; this comparison indicates 
that the distribution of size classes for the latter establishments 
is similar to the distribution of size classes for the 
establishments as a whole.
---------------------------------------------------------------------------

    Under the 0.95 sensitivity-test criterion value for the ANSI 
Z88.10-2001 standard, about 3,980 employees with improperly fitting 
respirators would pass the proposed ABQLFT protocol each year (i.e., a 
0.018% false-positive rate x 221,100 total employees tested), while the 
0.92 sensitivity-test value obtained for the proposed protocol would 
result in about 5,306 employees passing the test with improperly 
fitting respirators (i.e., a 0.024% false-positive rate x 221,100 total 
employees tested). OSHA believes that the 3,980 employees with false-
positive values that would result from using the sensitivity-test 
criterion from the ANSI standard are too high; therefore, adding 1,326 
employees each year to this already excessive figure is unacceptable. 
Contrary to the previously cited statement made by Mr. Weber from 3M, 
OSHA finds that the significance between test sensitivity values of 
0.92 and 0.95, when viewed in practical terms, is highly significant 
because an additional 1,326 employees would not have adequate 
respiratory protection in the workplace. OSHA believes that the 
contribution of ANSI Z88.10-2001 to the process of evaluating proposed 
respirator fit-testing protocols is to provide procedures that OSHA can 
use in determining the practical effects of errors that result from the 
administration of these proposed protocols. Therefore, based on this 
analysis involving the sensitivity-test criterion from the ANSI 
standard, OSHA concludes that it cannot include the proposed ABQLFT 
protocol among the qualitative fit tests currently listed in Part I.B 
of Appendix A of its Respiratory Protection Standard.
    Regarding the second part of this issue (i.e., that the sensitivity 
calculations may not be the best indicator of fit-test performance), 
the authors of the study recommended using binary logistic-regression 
analysis to determine sensitivity of the proposed protocol instead of 
the test-sensitivity criterion specified by ANSI Z88.10-2001. Every 
comment submitted to the record opposed this recommendation. For 
example, NIOSH stated:

    A second cited journal article [Nelson and Mullins 2004] 
examined the treatment of data from previously reported studies, 
including the 2003 Nelson study, by use of a new method of data 
analysis. A more thorough evaluation of the method of data analysis 
should be undertaken to ensure the studies used to validate the new 
method include an appropriate range of fit factors and respirator 
designs.
* * * * *
    The argument by the study authors that "the method used to 
determine acceptability should be independent of specific data 
collected" is not convincing. A sufficient number of subjects met 
fit testing requirements using the ABQLFT protocol and failed using 
the GAQNFT protocol. These results were determined to be below the 
ANSI Z88.10-2001 recommended criteria of 0.95 for the test-sensitivity 
value. Recalculating test sensitivity (proportion of failed reference 
method fit tests that also failed the new fit-test method) via alternative 
statistical techniques, or questioning the validity of the sensitivity 
calculation as an appropriate indicator of fit-test method performance to 
rationalize a positive conclusion, is a questionable response to the study 
outcome. The sensitivity test is a critical criterion to ensure the 
rejection of inadequately fitting respirators. Because the observed 
value of 0.92 is below the ANSI criterion of 0.95, NIOSH considers 
the value unacceptable. If the method of data analysis is changed, 
the new method needs to be thoroughly evaluated before challenging 
the standard criterion. (See Ex. OSHA-2007-0006-0026.)

Bill Kajola of the AFL-CIO recommended that OSHA not sanction the 
binary logistic-regression analysis as an alternate method for 
analyzing the study results, stating, "There is no data or 
confirmation to suggest that a `binary logistic regression analysis' is 
an appropriate and adequate means to evaluate a new fit test method" 
(OSHA-2007-0006-0019.1). James S. Johnson believed it was premature to 
use binary logistic-regression analysis to analyze the study data, 
asserting that "[t]he proposed change is too significant to be based 
on one study that has to have additional mathematical analysis and 
assumptions proposed to pass the ANSI Z88.10 requirements" (Ex. OSHA-
2007-0006-0028). Daniel K. Shipp of the International Safety Equipment 
Association commented that binary logistic-regression analysis "be 
validated by an additional source" (Ex. OSHA-2007-0006-0027).
    As noted earlier, none of the comments submitted to the record 
supported using binary logistic-regression analysis to interpret the 
study results. These comments clearly indicate that this analytic 
technique is currently inappropriate for use in determining the 
sensitivity of fit-testing protocols. OSHA agrees with these comments, 
and believes that the technique requires additional validation before 
it will be acceptable for this purpose.
    6. What is the significance of limiting the ABQLT to respirator 
users who demonstrate Level 1 sensitivity to Bitrex®? Few 
commenters responded to this issue. NIOSH observed that information 
about "the number or percentage of subjects in [the] study who did not 
meet Level 1 sensitivity to Bitrex®" was not available in the 
article describing the study (see Ex. OSHA-2007-0006-0003), and, 
therefore, "NIOSH is unable to estimate the proportion of workers in 
the population who demonstrate Level 1 sensitivity to Bitrex®" 
(Ex. OSHA-2007-0006-0026). As a result, NIOSH found that "the utility 
of the proposed ABQLFT protocol can not be determined at this time." 
James S. Johnson commented that determining Level 1 sensitivity is a 
restriction that "adds another level of complexity to the test 
protocol" (Ex. OSHA-2007-0006-0028). Ching-tsen Bien believed that 
using Level 1 sensitivity for screening purposes "does not prevent 
some test conductors who ignore this limitation and use the ABQLFT 
method to fit test any worker, and it may result in the selection of 
[the] wrong respirator for workers with Levels 2 or 3 sensitivity * * 
*" (Ex. OSHA-2007-0006-0017.1). None of these comments challenged the 
validity or accuracy of the Level 1 sensitivity procedure; accordingly, 
OSHA concludes that the ABQLFT study used the procedure appropriately, 
and that it accurately screened the test subjects for sensitivity to 
Bitrex®.
    7. Miscellaneous issues addressed by the comments. Several 
commenters objected that the test subjects in the ABQLFT study did not 
perform seal checks while using the respirators. For example, James S. 
Johnson stated that "[t]he exclusion of the users seal check may bias 
the data and this isn't representative of how this procedure is 
normally done" (Ex. OSHA-2007-0006-0028). In response to the 
commenters, OSHA notes that the test subjects in the study used 
respirators that were one or two sizes too small or too large to ensure 
that a number of poor respirator fits occurred. This procedure induced 
poor facepiece-to-face seals, which caused the respirators to leak. 
These leaks, in turn, provided data for use in determining how 
effectively the proposed ABQLFT protocol detected such leaks. The 
authors of the ABQLFT study explained the absence of seal checks as 
follows: "Experience in this laboratory has shown that people who 
participate in fit tests on a frequent basis and who are allowed to 
perform user seal checks can adjust most respirators to fit well enough 
to pass a fit test (Janssen, 2002). For this reason, the subjects were 
instructed to adjust the facepiece until comfortable but were not 
permitted to perform a user seal check" (Ex. OSHA-2007-0006-0003). 
Therefore, OSHA concludes that removing seal checks from the study was 
necessary to obtain leakage data for use in determining the 
effectiveness of the proposed ABQLFT protocol.

D. Conclusions

    Based on a complete and thorough review of the rulemaking record, 
OSHA concludes that:
    1. The study was well controlled, and conducted according to 
accepted experimental design practices and principles.
    2. The authors of the studies described in the submitted articles 
presented the the results properly, fully, and fairly in the context of 
the ANSI Z88.10-2001 consensus standard.
    3. The results generated by the proposed protocol provided 
reproducible fit-testing results, and the experiments and analyses were 
adequate for this purpose.
    4. The results for the proposed protocol were reliable, but OSHA 
can reach no conclusion regarding how the proposed protocol compares to 
other qualitative fit-testing protocols because the study did not make 
these comparisons. Additionally, the study did not demonstrate that the 
proposed protocol accurately determined fit for N95 filtering-facepiece 
respirators; therefore, OSHA could not approve the proposed protocol 
for fit testing this class of respirators.
    5. The test-sensitivity value of 0.92 would increase substantially 
the number of employees who would pass the proposed protocol with 
improperly fitting respirators, thereby making the proposed protocol 
unacceptable for listing in Part I.B. of Appendix A of OSHA's 
Respiratory Protection Standard. In addition, using binary logistic-
regression analysis as a substitute for the sensitivity-test criterion 
in ANSI Z88.10-2001 is premature because the analysis requires 
additional validation.
    6. The results indicate that limiting the proposed protocol to test 
subjects who demonstrated Level 1 sensitivity to Bitrex® was 
appropriate.
    7. To ensure adequate respirator leakage, the study justifiably 
omitted seal checks from the experimental procedures.
    Additional validation testing of, or revisions to, the proposed 
ABQLFT protocol may provide new results for the protocol that meet or 
exceed the sensitivity-test criterion established by the ANSI Z88.10 
consensus standard. After submitting these new results and supporting 
documentation to OSHA, OSHA would evaluate this information and, if 
appropriate, would submit it to the public for notice and comment. If 
the revised protocol is to apply to filtering-facepiece respirators, 
then the resubmission should include testing on these respirators 
demonstrating that the revised protocol accurately identifies poor fit 
among test subjects who use them.

List of Subjects in 29 CFR Part 1910

    Hazardous substances, Health, Occupational safety and health, Toxic 
substances.

Authority and Signature

    Jordan Barab, Acting Assistant Secretary of Labor for Occupational 
Safety and Health, U.S. Department of Labor, 200 Constitution Avenue, 
NW., Washington, DC 20210, directed the preparation of this notice. 
Accordingly, the Agency issues this notice under the following 
authorities: Sections 4, 6(b), 8(c), and 8(g) of the Occupational 
Safety and Health Act of 1970 (29 U.S.C. 653, 655, 657); Section 3704 
of the Contract Work Hours and Safety Standards Act (40 U.S.C. 3701 et 
seq.); Section 41 of the Longshore and Harbor Worker's Compensation Act 
(33 U.S.C. 941); Secretary of Labor's Order No. 5-2007 (72 FR 31160); 
and 29 CFR part 1911.

    Signed at Washington, DC, on June 22, 2009.
Jordan Barab,
Acting Assistant Secretary of Labor for Occupational Safety and Health.
[FR Doc. E9-14979 Filed 6-24-09; 8:45 am]

BILLING CODE 4510-26-P


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