Document ID: OSHA-2007-0007-0027
Agency: osha
Document Type: Proposed Rule
Title: Withdrawl of Additional Quantitative Fit-testing Protocols for the Respiratory Protection Standard
Posted Date: 2010-01-27T05:00Z

[Federal Register: January 27, 2010 (Volume 75, Number 17)]
[Proposed Rules]               
[Page 4323-4331]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr27ja10-28]                         

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DEPARTMENT OF LABOR

Occupational Safety and Health Administration

29 CFR Part 1910

[Docket No. OSHA-2007-0007]
RIN 1218-AC39

 
Additional Quantitative Fit-testing Protocols for the Respiratory 
Protection Standard

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 concludes 
that the revised PortaCount[supreg] quantitative fit-testing protocols 
are not sufficiently accurate or reliable to include among the 
quantitative fit 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 
revised protocols after developers of the protocols address the issues 
described in this notice.

DATES: The proposed rulemaking is withdrawn as of January 27, 2010.

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.
    Copies of this notice: 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

    Appendix A of OSHA's Respiratory Protection Standard at 29 CFR 
1010.134 currently includes three quantitative fit-testing protocols 
using the following challenge agents: a non-hazardous generated aerosol 
such as corn oil, polyethylene glycol 400, di-2-ethyl hexyl sebacate, 
or sodium chloride; ambient aerosol; and controlled negative pressure. 
Appendix A of the Respiratory Protection Standard also specifies the 
procedure for adding new fit-testing protocols to the standard. The 
criteria for determining whether OSHA must publish a fit-testing 
protocol for notice-and-comment rulemaking under Section 6(b)(7) of the 
Occupational Safety and Health Act of 1970 (29 U.S.C. 655) 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. Using 
this procedure, OSHA added one fit-testing protocol (i.e., the 
controlled negative pressure REDON quantitative fit- testing protocol) 
to Appendix A of

[[Page 4324]]

its Respiratory Protection Standard (see 69 FR 46986). OSHA also 
published on December 26, 2007, a Notice of Proposed Rulemaking 
requesting public comment on an abbreviated Bitrex[supreg] qualitative 
fit-testing protocol (see 72 FR 72971). Subsequently, OSHA withdrew, 
without prejudice, this fit-testing protocol from the rulemaking 
process, and invited the developers of the protocol to conduct further 
research addressing issues described in the withdrawal notice (see 74 
FR 30250).

II. Summary and Explanation of the Withdrawal Notice

A. Introduction

    In a letter submitting two new quantitative fit-testing protocols 
for review under the provisions of Appendix A of OSHA's Respiratory 
Protection Standard (Ex. OSHA-2007-0007-0001), Mr. Jeff Weed of TSI, 
Inc., included a copy of a peer-reviewed article from an industrial-
hygiene journal describing the accuracy and reliability of these 
proposed protocols (Ex. OSHA-2007-0007-0002).\1\ The submission letter 
also included instructions that described in detail the equipment and 
procedures required to administer the proposed protocols. According to 
this description, the proposed protocols are variations of the existing 
ambient-aerosol condensation-nuclei-counter quantitative fit-testing 
protocol developed by TSI, Inc., in the 1980s, commonly referred to as 
the PortaCount[supreg] quantitative fit-testing protocol (hereafter, 
``the standard PortaCount[supreg] QNFT protocol''). OSHA included the 
standard PortaCount[supreg] QNFT protocol in Appendix A of its final 
Respiratory Protection Standard. (For consistency, OSHA will refer to 
the two proposed protocols as ``revised PortaCount[supreg] quantitative 
fit-testing protocols 1 and 2'' (i.e., ``revised PortaCount[supreg] 
QNFT protocols 1 and 2'').
---------------------------------------------------------------------------

    \1\ This letter and the accompanying article describe three fit-
testing protocols, but Mr. Weed of TSI Inc., in a subsequent 
telephone call to OSHA staff, requested that the Agency include only 
two of them in the proposed rulemaking.
---------------------------------------------------------------------------

    The proposed protocols use the same fit-testing requirements and 
instrumentation specified for the standard PortaCount[supreg] QNFT 
protocol in paragraphs (a) and (b) of Part I.C.3 of Appendix A of the 
Respiratory Protection Standard, with the following exceptions:
     Revised PortaCount[supreg] QNFT protocol 1 reduces the 
duration of the eight fit-testing exercises from 60 seconds to 30 
seconds; and
     Revised PortaCount[supreg] QNFT protocol 2 eliminates two 
of the eight fit-testing exercises, with each of the remaining six 
exercises having a duration of 40 seconds; in addition, this proposed 
protocol increases the current minimum pass-fail fit-testing criterion 
(i.e., reference fit factors) from a fit factor of 100 to 200 for half 
masks, and from 500 to 1000 for full facepieces.
    Peer-reviewed industrial-hygiene journal article. The peer-reviewed 
article submitted by TSI, Inc., entitled `'Evaluation of Three New Fit 
Test Protocols for Use With the TSI PortaCount[supreg],'' appeared in 
the Fall/Winter 2005 issue of the Journal of the International Society 
for Respiratory Protection (Ex. OSHA-2007-0007-0003). The article 
describes a study that determined whether performing the proposed 
protocols yields fit-testing results similar to results obtained with 
the standard PortaCount[supreg] QNFT protocol (hereafter referred to as 
``the Study'').\2\
---------------------------------------------------------------------------

    \2\ The standard PortaCount[supreg] QNFT protocol was the 
criterion measure or ``gold standard.''
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    Test subjects and respirator selection. The Study involved 30 test 
subjects who performed 140 fit tests while wearing elastomeric half-
mask and full-facepiece respirators equipped with P100 filters. The 
test subjects selected respirators from among 24 models, with some test 
subjects using more than one model during fit testing. Respirator fit 
varied across the test subjects, with 60 of 140 fit factors below 100, 
and 91 of 140 fit factors less than 500, as determined by the standard 
PortaCount[supreg] QNFT protocol. Poor respirator fit resulted from 
improper respirator selection by the test subjects themselves, or from 
assigning respirators to test subjects that were either too small or 
too large. Test subjects could adjust the respirator for comfort, but 
they did not perform user seal checks.
    Procedures. In conducting the Study, the authors followed the 
recommendations for evaluating new fit-testing protocols specified by 
Annex A2 (``Criteria for Evaluating Fit Tests Methods'') of ANSI 
Z88.10-2001 (``Respirator Fit-testing Methods''). Specially designed 
testing software allowed for the calculation of fit factors every 10 
seconds during the in-mask sampling periods without disturbing the 
facepiece (i.e., at 10-, 20-, and 30-second intervals for comparison 
with the 40-second in-mask sampling intervals determined using the 
standard PortaCount[supreg] QNFT protocol). The authors used a TSI 
PortaCount[supreg] Plus Model 8020[supreg] quantitative fit-test system 
to assess respirator fit; the system used a TSI-supplied sampling 
adaptor, or fixed probes provided by the respirator manufacturer, to 
collect samples inside the respirators. The sampling point inside the 
respirator was between the nose and the mouth. During sampling, the 
test subjects performed the exercises listed in Part I.A.14 of Appendix 
A of OSHA's Respiratory Protection Standard, which include: initial 
normal breathing, deep breathing, turning the head side to side, moving 
the head up and down, reading a passage, grimace, bending over, and 
final normal breathing. The TSI PortaCount[supreg] Plus fit-testing 
instrument performed particle counts on samples collected during the 
Study. Table 1 provides the exercise and sampling parameters for each 
of the protocols used in the Study.

                                                     Table 1
----------------------------------------------------------------------------------------------------------------
                                                                                                In-Mask sampling
                                                             Number of       Duration of each  duration for each
                        Protocol                             exercises           exercise           exercise
                                                                                (seconds)        (seconds) \1\
----------------------------------------------------------------------------------------------------------------
Standard PortaCount[supreg] QNFT Protocol..............                  8                 60                 40
Revised PortaCount[supreg] QNFT Protocol 1.............                  8                 30                 10
Revised PortaCount[supreg] QNFT Protocol 2.............              \2\ 6                 40                 20
----------------------------------------------------------------------------------------------------------------
\1\ Does not include 20 seconds for each exercise to collect ambient-air samples and to purge the in-mask and
  ambient-air sampling tubes.
\2\ This protocol eliminated the initial normal-breathing exercise and the deep-breathing exercise.

[[Page 4325]]

    Results. The Study results describe the performance of the two 
revised PortaCount[supreg] QNFT protocols in relation to the reference 
fit factors (RFFs) that the proposed protocols designate as pass-fail 
criteria for half-mask respirators (100 and 200 for protocols 1 and 2, 
respectively) and full-facepiece respirators (500 and 1000 for 
protocols 1 and 2, respectively). However, OSHA could not evaluate the 
results for each type of respirator separately because the analyses 
performed in the Study grouped fit-testing results from half-mask 
respirators with fit-testing results from full-facepiece respirators. 
In this regard, Table III of the Study showed 69 fit tests for half-
mask respirators and 71 fit tests for full-facepiece respirators, for a 
total of 140 fit tests. However, the results in Table III of the Study 
also list 140 fit tests for RFFs < 100 and > 100, and another 140 fit 
tests for RFFs < 500 or > 500, when the number of fit tests for each 
set of RFFs should be 69 and 71, respectively (i.e., 69 fit tests for 
RFFs < 100 and > 100, with these RFFs to be applicable to half-mask 
respirators, and 71 fit tests for RFFs < 500 and > 500, with these RFFs 
to be applicable to full-facepiece respirators).\3\
---------------------------------------------------------------------------

    \3\ RFFs > 100 include RFFs > 200, which were to be applicable 
to half-mask respirators, while RFFs > 500 include RFFs > 1000, 
which were to be applicable to full-facepiece respirators.
---------------------------------------------------------------------------

    Using the standard PortaCount[supreg] QNFT protocol as the 
criterion measure, the Study described the fit-testing results obtained 
with the revised PortaCount[supreg] QNFT protocols using the following 
statistics: test sensitivity; predictive value of a pass; test 
specificity; predictive value of a fail; and the kappa statistic. These 
statistics derive from the variables defined by ANSI Z88.10-2001, in 
which: A = false positives (passed the fit test with a fit factor < 
RFF); B = true positives (passed the fit test with a fit factor >= 
RFF); C = true negatives (failed the fit test with a fit factor < RFF); 
D = false negatives (failed the fit test with a fit factor >= RFF); Po 
= observed proportion of the two fit tests that are concordant; and Pe 
= expected proportion of the two fit tests expected to be concordant 
when the two tests are statistically independent. 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; predictive value of a fail = C/(C + 
D), RV > 0.50; and the kappa statistic = (Po-Pe)/(1-Pe). The following 
tables list the values of these descriptive statistics for revised 
PortaCount[supreg] QNFT protocols 1 (at RFFs of 100 and 500) and 2 (at 
RFFs of 200 and 1000).

                             Table 2--Descriptive Statistics for RFFs of 100 and 200
----------------------------------------------------------------------------------------------------------------
                                                                                Revised             Revised
                                                                          PortaCount[supreg]  PortaCount[supreg]
                      Statistics                       ANSI  Requirement    QNFT Protocol 1     QNFT Protocol 2
                                                                               RFF = 100           RFF = 200
----------------------------------------------------------------------------------------------------------------
Sensitivity..........................................             >=0.95            \1\ 0.91                1.00
Predictive Value of a Pass...........................             >=0.95            \2\ 0.94                1.00
Specificity..........................................              >0.50                0.99                0.81
Predictive Value of a Fail...........................              >0.50                0.98                0.79
Kappa Statistic......................................              >0.70                0.91                0.78
----------------------------------------------------------------------------------------------------------------
\1\ = Fail; \2\ = Borderline fail.

                            Table 3--Descriptive Statistics for RFFs of 500 and 1000
----------------------------------------------------------------------------------------------------------------
                                                                                Revised             Revised
                                                                          PortaCount[supreg]  PortaCount[supreg]
                      Statistics                        ANSI Requirement    QNFT Protocol 1     QNFT Protocol 2
                                                                               RFF = 500          RFF = 1000
----------------------------------------------------------------------------------------------------------------
Sensitivity..........................................             >=0.95                0.97                1.00
Predictive Value of a Pass...........................             >=0.95            \1\ 0.94                1.00
Specificity..........................................               >0.5                0.98                0.84
Predictive Value of a Fail...........................              >0.50                0.99                0.92
Kappa Statistic......................................              >0.70                0.94                0.87
----------------------------------------------------------------------------------------------------------------
\1\ = Borderline fail.

    For a RFF of 100, revised PortaCount[supreg] QNFT protocol 1 failed 
to meet the sensitivity value specified by ANSI Z88.10-2001, and, 
consistent with this failure, the value for the predictive value-of-a-
pass statistic was marginal. However, for a RFF of 500, the sensitivity 
value for this proposed protocol exceeded the ANSI requirement, 
although the predictive value-of-a-pass statistic was again slightly 
below the ANSI specification. The failure of protocol 1 to achieve the 
sensitivity value specified by ANSI Z88.10-2001 at a RFF of 100 
indicates that the proposed protocol is susceptible to alpha, or false 
positive, error--i.e., it would pass some half masks that would 
function below a fit factor of 100 when tested with the protocol used 
as the criterion measure (i.e., the standard PortaCount[supreg] QNFT 
protocol). This failure to meet the sensitivity value specified by ANSI 
Z88.10-2001 raises a question of whether revised PortaCount[supreg] 
QNFT protocol 1 is as protective as the standard PortaCount[supreg] 
QNFT protocol. For protocol 1, the authors reported values well above 
the values established by the ANSI standard for the three remaining 
statistics, including specificity, predictive value of a fail, and the 
kappa statistic. However, the grouping of results for half-mask and 
full-facepiece respirators brings the applicability of these statistics 
into question.
    For PortaCount[supreg] QNFT protocol 2, the sensitivity values for 
both RFFs were well in excess of the sensitivity value specified by the 
ANSI standard. The sensitivity values for this proposed protocol 
indicate that it identified 100% of the poorly fitting half-mask and 
full-facepiece respirators. In addition, this

[[Page 4326]]

proposed protocol performed well above the values listed in the ANSI 
standard for the four remaining variables, including predictive value 
of a pass, specificity, predictive value of a fail, and the kappa 
statistic. Consistent with the sensitivity values derived for this 
proposed protocol, these four values indicate that the proposed 
protocol accurately determined whether respirators achieved, or failed 
to achieve, RFFs of 200 and 1000. Nonetheless, as mentioned above, the 
grouping of results for half-mask and full-facepiece respirators brings 
the applicability of these statistics into question.
    In discussing the results for revised PortaCount[supreg] QNFT 
protocol 2, the authors asserted that excluding the two least strenuous 
fit-testing exercises (i.e., the initial normal-breathing exercise and 
the deep-breathing exercise) from this proposed protocol was a 
conservative approach in that the proposed protocol was more likely 
than protocols consisting of eight fit-testing exercises to detect 
respirator leakage (i.e., using data from less strenuous fit-testing 
exercises inappropriately inflates the overall fit factor for 
respirators, thereby increasing alpha error). Another conservative 
approach used by this proposed protocol was raising the RFFs for half 
masks from a fit factor of 100 to 200, and, for full-facepiece 
respirators, from 500 to 1000. While this approach may have enhanced 
the sensitivity of the proposed protocol, it may also increase beta 
(false-negative) error; beta error would increase the number of 
repeated tests and, consequently, the total testing time required by 
some employees to identify a respirator having an acceptable fit.

B. Decision To Publish the Two Protocols for Notice-and-Comment 
Rulemaking

    OSHA reviewed the information submitted by TSI, Inc., in support of 
these proposed protocols to determine whether the protocols met the 
criteria for determining whether OSHA must publish new fit-testing 
protocols for notice-and-comment rulemaking established by the Agency 
in Part II of Appendix A of its Respiratory Protection Standard. The 
Agency concluded that the proposed protocols warranted notice-and-
comment rulemaking under Section 6(b)(7) of the Act (29 U.S.C. 655), 
and initiated rulemaking to determine whether to approve these proposed 
protocols for inclusion in Part I of Appendix A of its Respiratory 
Protection Standard. OSHA published the proposal in the Federal 
Register on January 21, 2009 (see 74 FR 3526).

C. Issues Raised for Public Comment

    In the Federal Register notice announcing the proposal, OSHA 
invited comments, information, and data from the public regarding the 
accuracy and reliability of the proposed protocols, effectiveness of 
the protocols in detecting respirator leakage, and the usefulness of 
the protocols 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 peer-reviewed journal 
article well controlled, and conducted according to accepted 
experimental design practices and principles?
     Were the results of the studies described in this article 
properly, fully, and fairly presented and interpreted?
     Will the proposed protocols generate reproducible fit-
testing results?
     Will the proposed protocols reliably identify respirators 
with unacceptable fit as effectively as the quantitative fit-testing 
protocols, including the standard PortaCount[supreg] QNFT protocol, 
already listed in Part I.C.3 of Appendix A of the Respiratory 
Protection Standard?
     Is the test-sensitivity value of 0.91 obtained for half 
masks by revised PortaCount[supreg] QNFT protocol 1 acceptable in view 
of the test-sensitivity value of 0.95 required by ANSI Z88.10-2001; if 
not, would it be appropriate for OSHA to limit application of revised 
PortaCount[supreg] QNFT protocol 1 to full-facepiece respirators?
     The Study evaluating the proposed protocols involved only 
elastomeric half-mask and full-facepiece respirators. Accordingly, is 
it appropriate to apply the results of the Study to other types of 
respirators (e.g., filtering-facepiece respirators)?

D. Summary of the Public Comments Received

    Twenty-six commenters submitted responses to the proposal. The 
following paragraphs in this section address the responses made to each 
of the six issues described previously.
1. Were the studies described in the peer-reviewed journal article well 
controlled, and conducted according to accepted experimental design 
practices and principles?
    In addressing this issue, the National Institute of Occupational 
Safety and Health (NIOSH) stated:

    [The Study] 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. 
However, the study design did not include filtering-facepiece 
respirators (FFR), nor sufficient fit test trials for half-mask 
respirators or full facepiece respirators to provide data that would 
allow independent assessment of the performance of the proposed 
revised protocols for either facepiece type. To fully assess the 
acceptability of the new protocols for applicability to half-mask 
respirators (including filtering-facepiece respirators) and full 
facepiece respirators, each facepiece type needs to be evaluated 
separately. The data analyses reported in the peer-reviewed journal 
article grouped fit test results for the half-mask and full 
facepiece respirators to obtain the minimum number for paired data 
sets required by ANSI Z88.10-2001, Annex A2. (See Ex. OSHA-2007-
0007-0016.1.)

    James S. Johnson (Ex. OSHA-2007-0007-0023.1) and Ching-tsen Bien 
(Ex. OSHA-2007-0007-0017.1) both disapproved of the Study's 
experimental design practices and principles, and specifically 
criticized the grouping of results for half-mask and full-facepiece 
respirators. OSHA agrees that grouping results for half-mask and full-
facepiece respirators in analyzing RFFs is a major limitation of this 
study (see, also, the discussion of this issue in paragraph D.2 of this 
section).
    Similar to NIOSH, Ching-tsen Bien questioned the number of fit-test 
trials performed in the Study. Mr. Bien stated: ``The ANSI Z88.10-2001 
requires a minimum of 100-paired tests. The proposed protocol only 
contains 69-paired tests for the half-mask, and 71-paired test sets for 
the full facepiece. It failed to meet this requirement.'' In addition, 
the American Federation of Labor and Congress of Industrial 
Organizations (AFL-CIO) criticized the Study for using only 30 
participants to generate fit-test data (Ex. OSHA-2007-0007-0015).
    In response to the assertion that the Study did not consist of as 
many fit tests as required under ANSI Z88.10-2001, OSHA emphasizes that 
it has not adopted the criteria in ANSI Z88.10-2001 as absolute 
requirements for new fit-testing protocols. Nonetheless, as NIOSH and 
Mr. Bien note, it appears that the Study did not consist of a 
sufficient number of fit tests to establish the respirator-specific 
performance of the proposed protocols. In response to the AFL-CIO, OSHA 
notes that researchers should, ideally, validate fit-testing protocols 
on a large number of study participants to account for variability 
across the population of employees who use the respirators. However, 
OSHA believes the total number of study participants is less

[[Page 4327]]

important than the total number of fit tests the participants perform.
    NIOSH also criticized the calculation of fit factors for the 
proposed protocols that used subsets of measurements taken during a 
standard PortaCount[supreg] fit-test (Ex. OSHA-2007-0007-0016.1). In 
its comment, NIOSH stated:

    For the results of the fit test using shortened exercises to be 
similar to the reference protocol, the fit of the respirator must 
not change significantly over time for each fit test exercise. The 
data are inadequate to demonstrate reproducible fit-testing results 
for either proposed protocol. Therefore, any subsequent assessment 
of conformance or non-conformance with the ANSI Z88.10-2001 
acceptance criteria cannot be presumed to be valid. Further 
investigation is required to compare potential changes in fit across 
the proposed 30- and 40-second exercise intervals in the reference 
protocol * * *. No information is provided in either the peer-
reviewed journal article or application to OSHA that demonstrates 
the proposed shortened exercise times would encompass the most 
challenging aspects of each exercise. 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.

    Clifton D. Crutchfield (Ex. OSHA-2007-0007-0019.1) and NIOSH (Ex. 
OSHA-2007-0007-0016.1) also questioned the assertion by the Study's 
authors that removal of the initial normal-breathing exercise and the 
deep-breathing exercises from revised PortaCount[supreg] QNFT protocol 
2 results in a conservative fit test. Dr. Crutchfield cited a number of 
studies to support the proposition that the normal-breathing exercise 
fit factor is among the lowest of the exercise fit factors, and that 
its elimination would produce a higher, less conservative, overall fit 
factor.
    The Agency believes that researchers cannot evaluate validly the 
effects of shortened exercises on respirator fit using subsets of 
sampling data from a standard, full-length respirator fit test because 
respirator fit may vary during an exercise. Additionally, OSHA believes 
that Dr. Crutchfield raised important questions about the removal of 
the normal-breathing and deep-breathing exercises that the Study's 
limited data presentation does not fully rebut (see item D.2 of this 
section).
    The Department of Defense (DOD) commented that the Study design was 
appropriate, but deviated from the ANSI protocol in that user seal 
checks were not conducted (Ex. OSHA-2007-0007-0021.1). DOD stated:

    The DOD views user seal checks to be a necessary element in any 
respirator program and user seal checks should have been conducted 
even if the test subject was identified as testing a poorly fitting 
facepiece. User seal checks are required for performing fit-testing 
by the OSHA Respirator Standard and by ANSI Z88.10-2001.

    In response to this comment, OSHA notes that some study 
participants used respirators that were 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 revised PortaCount[supreg] QNFT protocols detected such 
leaks. Therefore, although the Study did not present a rationale for 
excluding seal checks, OSHA concludes that the Study needed leakage 
data to determine the efficacy of the revised PortaCount[supreg] QNFT 
protocols, which justified the omission.
    Ching-tsen Bien (Ex. OSHA-2007-0007-0017.1) and Larry Janssen (Ex. 
OSHA-2007-0007-0018.1) recommended that the authors of the Study 
validate the revised PortaCount[supreg] QNFT protocols using a 
generated-aerosol procedure in a test chamber. In this regard, Mr. Bien 
commented:

    The PortaCount[supreg] is a field instrument but not a research 
instrument. For a validation study, the testing should be performed 
inside a test chamber with a uniform and constant stable 
concentration. The fit test results should be reported continuously, 
rather than at selected time intervals. The PortaCount[supreg] 
utilizes the ambient air as a test agent and the test results may be 
affected by a change in air particle concentration.

    Similarly, Clifton D. Crutchfield wrote (Ex. OSHA-2007-0007-0019.1) 
that the use of the standard OSHA PortaCount[supreg] protocol as a 
reference measure for new protocols ``presents a real quandary because 
the sensitivity of the standard PortaCount protocol has itself not been 
established.''
    In response to these criticisms regarding the use of the standard 
PortaCount[supreg] protocol as a reference measure, OSHA notes that 
none of the existing fit-testing procedures, including generated-
aerosol methods, has been validated as a reference tool. In the absence 
of a fully validated reference test, OSHA requires that new QNFT 
protocols be evaluated against accepted QNFT methods. Thus, the Agency 
allows QNFT protocols to be tested against ambient-aerosol protocols, 
and ANSI Z88.10-2001 provides guidelines for evaluating new QNFT 
protocols against any of the currently accepted QNFT procedures.
    In summary, the commenters raised a number of valid concerns 
regarding the methodology used in the Study. The Agency concludes that 
the Study did not implement accepted experimental design practices to 
the extent necessary to include the revised PortaCount[supreg] QNFT 
protocols to Appendix A of the Respiratory Protection Standard.
2. Were the results of the studies described in this article properly, 
fully, and fairly presented and interpreted?
    NIOSH (Ex. OSHA-2007-0007-0016.1), James S. Johnson (Ex. OSHA-2007-
0007-0023.1), and Ching-tsen Bien (Ex. OSHA-2007-0007-0017.1) 
criticized the failure to differentiate clearly the results for half-
mask and full-facepiece respirators. Mr. Bien stated:

    The purpose of this study should be the comparison between the 
revised PortaCount and the regular PortaCount methods. Both half-
mask and full-facepiece elastomeric respirators were selected for 
this study. There should be two sets of data, one for each type of 
mask, since the passing criterion is different for each type of 
respirator. For each type of respirator, there should be two sets of 
data; one set for the 60-second exercise, and one set for shorter 
time or less exercises. Only one set of data is presented in the 
paper and it combines the half-mask and full-facepiece data.

    Similarly, James S. Johnson commented:

    Half-mask and full face piece respirators are normally 
considered two different types of air purifying respirators with 
different fitting, design and performance properties. The 
combination of these types of respirators into one set of data for 
analysis and conclusions doesn't appropriately recognize their 
performance differences.

    OSHA believes that the Study failed to properly differentiate the 
fit-testing results for half-mask and full-facepiece respirators. 
Although OSHA previously approved the controlled negative pressure 
(CNP) REDON fit-testing protocol based in part on a study that mixed 
fit-testing results for half-mask and full-facepiece respirators (Ex. 
2-2, Docket No. H-049C), the Agency finds the largely undifferentiated 
results from the revised PortaCount[supreg] QNFT protocols to be more 
problematic than the CNP REDON results. In the final rule on the CNP 
REDON protocol, OSHA explained that ``[w]hile the Agency agrees that * 
* * combining results for different respirator types may lead to 
inconsistent results with large statistical variations, the peer-
reviewed studies showed that large statistical variations did not 
occur.'' In contrast to the studies submitted for the CNP REDON 
protocol, the study for the revised PortaCount[supreg] QNFT protocols 
does not present results in sufficient detail to allow OSHA to examine 
the variation in fit-testing results. Moreover, while two peer-

[[Page 4328]]

reviewed journal articles supported the CNP REDON protocol, the article 
describing the Study is the sole publication supporting the revised 
PortaCount[supreg] QNFT protocols. Therefore, OSHA believes that the 
failure to differentiate fit-testing results for half-mask and full-
facepiece respirators obscures interpretation of the Study's statistics 
because (1) evaluating the variability of the test results for this 
study is impossible, and (2) the limited data presentation does not 
support the revised PortaCount[supreg] QNFT protocols.
    NIOSH (Ex. OSHA-2007-0007-0016.1) and Ching-tsen Bien (Ex. OSHA-
2007-0007-0017.1) noted that the Study failed to present clearly a 
number of important data. For both protocols, NIOSH noted that the 
Study provided ``[i]nsufficient detail and data concerning application 
of the recommended ANSI acceptance criteria for the number of tests 
performed and the distribution of good and poor fitting respirators in 
the test population.'' With regard to revised PortaCount[supreg] 
protocol 2, NIOSH cited a ``lack of detail, data and discussion of 
performance in relation to the unique acceptable fit factors of 200 for 
a half-mask and 1000 for a full facepiece respirator.'' Mr. Bien noted 
that the Study did not follow the ANSI Z88.10-2001 recommendation that 
investigators present a table containing information on respirator 
make, model, size, individuals tested, and the results of the new test 
and fit factors for the reference test. Mr. Bien also observed that 
``except for Figure 1 in the paper, the test data is not presented.''
    OSHA agrees that the Study did not present a sufficient level of 
detail regarding individual fit-testing results, the types of 
respirators selected, and the distribution of respirator fits in the 
test population. Although the Study provided a histogram showing the 
distribution of RFFs, these data are difficult to interpret in the 
absence of information about which fit factors derive from half-mask 
versus full-facepiece respirators.
3. Will the proposed protocols generate reproducible fit-testing 
results?
    Several commenters, including Ching-tsen Bien (Ex. OSHA-2007-0007-
0017.1), Clifton D. Crutchfield (Ex. OSHA-2007-0007-0019.1), and NIOSH 
(Ex. OSHA-2007-0007-0016.1) noted that the data presented in the Study 
do not facilitate an evaluation of reproducibility. Mr. Bien stated, 
``[s]ince the individual test data is not presented in the paper, there 
is no information to determine the data reproducibility.'' While 
similarly noting the absence of data describing the variability of fit-
testing results in the Study, Dr. Crutchfield drew OSHA's attention to 
the results of a study by Sreenath et al. (2001). Examining the results 
of this study, Dr. Crutchfield noted that data from 10-second mask 
samples had a larger standard deviation than the data from 60-second 
mask samples.
    NIOSH (Ex. OSHA-2007-0007-0016.1) also questioned the 
reproducibility of the fit-testing results from the revised 
PortaCount[supreg] QNFT protocols. Because revised PortaCount[supreg] 
QNFT protocol 1 did not meet the ANSI Z88.10-2001 acceptance criteria 
for sensitivity and predictive value of a pass, NIOSH concluded that 
protocol 1 would have ``a diminished likelihood of achieving 
reproducible fit-testing results when compared to the established 
method.'' With regard to revised PortaCount[supreg] QNFT protocol 2, 
NIOSH stated:

    The results of the Protocol 2 evaluation are insufficient to 
conclude that reproducible fit-testing results could be achieved 
using this protocol. The article does not describe whether each 
paired set represents the fit factors for a half mask or full 
facepiece respirator. It appears that some full facepiece respirator 
paired sets failed to meet the acceptable fit factor at 500. Thus, 
they were grouped with paired sets of data and treated as meeting 
the acceptable fit factor of 100, normally used for half mask 
respirators. These paired sets were also included in the data for 
failing to meet the required fit factor of 500, normally used for 
full facepiece respirators.

    OSHA believes that NIOSH's comments regarding test sensitivity and 
the predictive value of a pass address the accuracy, rather than the 
reproducibility, of the fit-test results. An evaluation of 
reproducibility would require information concerning the variability of 
the fit-testing results, which, as noted above, the Study did not 
provide. However, OSHA agrees that the reproducibility of the data is 
further obscured by the failure to differentiate clearly the fit-
testing results for both half-mask and full-facepiece respirators.
    James S. Johnson wrote (Ex. OSHA-2007-0007-0023.1) that 
``additional experimental work is needed to determine if the reported 
results are reproducible when obtained from a representative set of 
workers following the required manufacturer user instructions and using 
a user seal check.'' While additional information about the 
characteristics of the Study participants would allow OSHA to evaluate 
whether these participants were representative of employees who use the 
respirators, the Agency finds no evidence that the participants were 
unrepresentative of the employee population. In addition, while strict 
compliance with manufacturer instructions may improve fit-test 
performance, the commenter provided no data indicating that poor 
compliance with these instructions biased the Study results. Finally, 
as discussed above (see item D.1 of this section), OSHA determined that 
omitting seal checks was necessary to determine the efficacy of the 
revised PortaCount[supreg] QNFT protocols.
    Jeff Weed (Ex. OSHA-2007-0007-0014.1) expressed confidence in the 
reproducibility of the test results from revised PortaCount[supreg] 
QNFT protocols 1 and 2, and described the revised exercises as ``long 
enough to ensure that face leaks are accurately detected.'' Mr. Weed 
also asserted that the Study ``proved that shortened measurement yields 
the same result as the longer measurement.'' However, OSHA believes 
that Mr. Weed failed to address the issue of the reproducibility of the 
fit-testing results because he did not adequately explain the 
deficiencies in the data presentation identified elsewhere in this 
section.
    Several commenters, including DOD (Ex. OSHA 2007-0007-0021.1) and 
James Johnson (Ex. OSHA-2007-0007-0023.1) recommended that OSHA require 
additional validation testing before accepting revised 
PortaCount[supreg] QNFT protocol 1 or 2, implying that the results were 
not reproducible.
    In summary, the Study did not establish the reproducibility of test 
results for the revised PortaCount[supreg] QNFT protocols. The Study 
did not present test results or statistics describing the variability 
of the results of protocols 1 and 2. Moreover, because of the 
previously discussed flaws in the data analysis, a meaningful 
evaluation of the reproducibility of the results is not possible.
4. Will the proposed protocols reliably identify respirators with 
unacceptable fit as effectively as the quantitative fit-testing 
protocols, including the standard PortaCount[supreg] QNFT protocol, 
already listed in Part I.C.3 of Appendix A of the Respiratory 
Protection Standard?
    Jeff Weed (Ex. OSHA-2007-0007-0014.1) asserted that the revised 
PortaCount[supreg] QNFT protocols would perform as well as any of the 
QNFT methods, and that the differences between the reference methods 
and the proposed protocols ``can be easily explained in terms of the 
limited number of test subjects and instrument variability.'' OSHA 
believes that any fit-testing protocol based on a study that involved 
significant instrument

[[Page 4329]]

variability and small sample size, as well as a flawed data analysis 
and an inadequate data presentation, is of questionable validity and 
utility.
    In the view of NIOSH (Ex. OSHA-2007-0007-0016.1), DOD (Ex. OSHA-
2007-0007-0021.1), and Clifton D. Crutchfield (Ex. OSHA-2007-0007-
0019.1), the failure of revised PortaCount[supreg] QNFT protocol 1 to 
meet the ANSI Z88.10-2001 criteria demonstrates that this protocol will 
not identify respirators with unacceptable fit as effectively as the 
accepted QNFT protocols. Because revised PortaCount[supreg] QNFT 
protocol 2 met the ANSI Z88.10-2001 criteria, DOD concluded that 
protocol 2 would identify respirators with unacceptable fit as reliably 
as accepted QNFT methods. In contrast to this view, NIOSH found that 
``[u]ncertain data treatment * * * prevent[s] answering the question of 
whether revised PortaCount[supreg] QNFT protocol 2 will reliably 
identify respirators with unacceptable fit as effectively as [accepted 
QNFT] protocols,'' and ``[t]he report of the test-sensitivity [of this 
protocol] having surpassed ANSI criteria does not resolve 
uncertainty.'' Similarly, Ching-tsen Bien (Ex. OSHA-2007-0007-0017.1) 
wrote that ``[s]ince the individual test data is not available, it is 
not possible to determine whether the proposed test protocols would 
reliably identify respirators with unacceptable fit as effectively as 
the regular quantitative fit-testing protocols.''
    OSHA agrees with NIOSH and Mr. Bien that the flawed data analysis 
and inadequate presentation of fit-testing results (see item D.2 of 
this section) prevents the Agency from thoroughly evaluating whether 
either of the proposed protocols would reliably identify respirators 
with unacceptable fit as effectively as accepted quantitative fit-
testing protocols. However, the test-sensitivity value reported for 
revised PortaCount[supreg] QNFT protocol 1 indicates that this protocol 
would not identify respirators with unacceptable fit as reliably as 
accepted quantitative fit-testing protocols.
    Clifton D. Crutchfield questioned whether doubling the RFFs for 
revised PortaCount[supreg] QNFT protocol 2 is sufficient to compensate 
for the protocol's potential deficiency of test sensitivity, and 
asserted that Sreenath et al. (2001) multiplied the conventional RFFs 
by fourteen to ensure the sensitivity of a new protocol that relied on 
a 20-second in-mask sampling period (Ex. OSHA-2007-0007-0019.1). OSHA 
agrees that the Study did not discuss adequately the implications of 
doubling the RFFs. As noted in section A above, increasing the 
sensitivity of a protocol by raising the RFFs may increase beta (false-
negative) error, which would increase the number of repeated tests and, 
consequently, total testing time. Although the Study reported 
sensitivity and specificity values for revised PortaCount[supreg] QNFT 
protocol 2 that exceeded the ANSI criteria, the Study's flawed data 
analysis and inadequate data presentation bring into question the 
validity of these values.
    In conclusion, OSHA believes that the Study did not analyze or 
present the fit-testing results in a manner that demonstrates that the 
proposed protocols would reliably identify respirators with 
unacceptable fit as effectively as accepted quantitative fit-testing 
protocols.
5. Is the test-sensitivity value of 0.91 obtained for half masks by 
revised PortaCount[supreg] QNFT protocol 1 acceptable in view of the 
test-sensitivity value of 0.95 required by ANSI Z88.10-2001; if not, 
would it be appropriate for OSHA to limit application of revised 
PortaCount[supreg] QNFT protocol 1 to full-facepiece respirators? \4\
---------------------------------------------------------------------------

    \4\ See discussion of grouping fit-testing results for half-mask 
and full-facepiece respirators under section II.A (``Introduction'') 
of this notice. Accordingly, commenters generally responded to this 
issue as though the fit tests comprising RFFs < 100 and > 100 
consisted of fit tests for both half-mask and full-facepiece 
respirators, not just fit tests for half-mask respirators.
---------------------------------------------------------------------------

    Many commenters, including Clifton D. Crutchfield (Ex. OSHA-2007-
0007-0019.1), David Spelce (Ex. OSHA-2007-0007-0013.1), NIOSH (Ex. 
OSHA-2007-0007-0016.1), James Johnson (Ex. OSHA-2007-0007-0023.1), DOD 
(Ex. OSHA-2007-0007-0021.1), AFL-CIO (Ex. OSHA-2007-0007-0015), and 
Ching-tsen Bien (Ex. OSHA-2007-0007-0017.1) expressed the opinion that 
the test-sensitivity value of 0.91 is unacceptable, and that it would 
be inappropriate to accept revised PortaCount[supreg] QNFT protocol 1 
for use with half-mask or full-facepiece respirators. Dr. Crutchfield 
noted that ``[t]he test-sensitivity value of 0.95 was the only test 
statistic designated by ANSI in its Fit Test Methods standard as a 
criterion value that `shall' be met when accepting new fit test 
methods.'' NIOSH stated:
    The results reported in the peer-reviewed journal article for 
either reference fit factor (RFF) of protocol 1 do not meet the full 
criteria of the Annex A2 evaluation standard against which they are 
to be judged. As such, it would not be appropriate to accept the 
application of revised PortaCount[supreg] QNFT protocol 1 to either 
half-mask or full-facepiece respirators.

    Larry Janssen (Ex. OSHA-2007-0007-0018.1) and Jeff Weed (Ex. OSHA-
2007-0007-0014.1) commented that the test-sensitivity value of 0.91 is 
acceptable despite the ANSI criterion sensitivity value of 0.95. In 
explaining this position, Mr. Janssen stated that instrument 
variability is approximately 5% of the true value, and 
asserted that the variability of facepiece-to-face seal leakage in the 
Study would increase this variability by at least another 5%. Assuming 
an overall variability of at least 10%, he questioned whether it is 
meaningful to calculate sensitivity values to two decimal places. In 
addition, Mr. Janssen cited a study (Janssen, L.L., et al., 2002) that 
found that none of the three currently accepted quantitative fit-
testing protocols met the ANSI sensitivity criterion of 0.95, noting 
that ``it would be inappropriate for OSHA to hold new fit tests to a 
higher standard than the currently accepted fit tests can meet.'' 
Recognizing that the variability described by Mr. Janssen introduces 
error into fit-testing measurement, OSHA does not believe that 
increasing this error further by adopting a sensitivity value of 0.91 
would improve employee protection.
    OSHA believes that the ANSI Z88.10-2001 standard represents the 
consensus of the industrial-hygiene community regarding the criteria to 
use in assessing fit-testing protocols. The majority of the comments to 
the proposal indicated that the industrial-hygiene community generally 
supports using the ANSI standard for this purpose. Thus, despite Mr. 
Janssen's assertion of an inevitable 10% variability in any fit-testing 
protocol, and regardless of whether the accepted fit-testing protocols 
achieve the ANSI criteria, OSHA believes that the ANSI criteria are 
meaningful measures of performance for new fit-testing protocols, 
although it does not treat the ANSI criterion for test sensitivity as 
an absolute requirement for new fit-testing protocols. In considering 
the test-sensitivity value for the Abbreviated Bitrex Qualitative Fit-
Testing (ABQLFT) protocol, OSHA projected the annual number of 
employees with improperly fitting respirators who would pass the 
proposed ABQLFT protocol, which achieved a test-sensitivity value of 
0.92, and compared this estimate with the projected number of false-
positives expected if the ABQLT protocol achieved the ANSI sensitivity 
criterion of 0.95. OSHA deemed the excess number of false positives at 
the test-sensitivity of 0.92 to be unacceptable. (See 74 FR 30250, 
30254.) However, OSHA could not make this

[[Page 4330]]

determination for revised PortaCount[supreg] QNFT Protocol 1 because 
the Study did not present adequate fit-testing results to do so. 
Nonetheless, the frequency of ambient-aerosol fit testing (see NIOSH-
BLS survey, Ex. 6-3, Docket No. H-049C) indicates that, compared to a 
fit-testing protocol having a test sensitivity at the ANSI criterion of 
0.95, substantially more employees would receive false-positive fit-
testing results using revised PortaCount[supreg] QNFT protocol 1. Thus, 
OSHA concludes that the test-sensitivity value of 0.91 achieved by 
revised PortaCount[supreg] QNFT protocol 1 is too low to include this 
protocol in Appendix A of its final Respiratory Protection Standard.
    Jeff Weed recommended that the high test-sensitivity value obtained 
by revised PortaCount[supreg] QNFT protocol 1 at the RFF of 500 
justifies the protocol's acceptance at the RFF of 100 (Ex. OSHA-2007-
0007-0014.1). In this regard, Mr. Weed commented, ``The fact that the 
testing near 500 had better results than the near 100 results is 
indicative of the inherent limitations of this type of study including 
variability of face seal leaks, the instrumentation, and the 
statistical sample size (number of people).'' Mr. Weed also compared 
revised PortaCount[supreg] QNFT protocol 1 to the previously proposed 
ABQLFT protocol, which also failed to meet the ANSI criterion for test 
specificity. Mr. Weed stated, ``Any decision by OSHA to reject a 
protocol based on the ANSI criteria must be applied equally.''
    OSHA does not believe that the test-sensitivity value that the 
Study reported at the RFF of 500 justifies acceptance of revised 
PortaCount[supreg] QNFT protocol 1. Mr. Weed cites variability due to 
face leaks, instrumentation, and small sample size as possible 
explanations for an erroneous test-sensitivity result at the RFF of 
100. However, OSHA believes that the inconsistency of the test-
sensitivity values at RFFs of 100 and 500 raises doubt about both of 
these values. In addition, as discussed above (see item D.4 of this 
section), OSHA concluded that instrument variability or a small sample 
size does not justify acceptance of a protocol with flawed data 
analyses and inadequate data presentation, particularly when OSHA 
determined that the ANSI criterion for test sensitivity, although not 
an absolute requirement for new fit-testing protocols, is reasonable. 
Finally, OSHA does not treat the ANSI criteria for test sensitivity as 
absolute requirements for new fit-testing protocols. Therefore, OSHA 
would not base a decision to reject a protocol with inadequate test-
sensitivity solely on the ANSI criteria. In conclusion, OSHA finds that 
including revised PortaCount[supreg] QNFT protocol 1 in Appendix A of 
its final Respiratory Protection Standard is unwarranted because this 
protocol would allow a substantially larger number of employees to use 
improperly fitting respirators than would be the case for a protocol 
that achieves the 0.95 test-sensitivity criterion specified by ANSI 
Z88.10-2001.
6. The Study evaluating the proposed protocols involved only 
elastomeric half-mask and full-facepiece respirators. Accordingly, is 
it appropriate to apply the results of the Study to other types of 
respirators (e.g., filtering-facepiece respirators)?
    Jeff Weed (Ex. OSHA-2007-0007-0014.1) and Larry Janssen (Ex. OSHA-
2007-0007-0018.1) provided comments in favor of applying the Study 
results to untested respirator types. In support of this view, Mr. 
Janssen wrote, ``There are no data that suggest a measured amount of 
faceseal leakage for a Class 100 FFR would be somehow different that 
the same amount of leakage measured on elastomeric facepieces with 
Class 100 filters.'' Elaborating on this point, Mr. Weed stated:

    Leaks are leaks. An instrument used for QNFT does not ``know'' 
what type of respirator is attached to the end of the sample tube. 
The instrument cannot know the path taken by a particle found in the 
breathing zone of a respirator. Particles are either present, or not 
present. As far as the instrument is concerned, there is no 
difference between leaks in an elastomeric face seal vs. the seal of 
a filtering-facepiece. The McKay study was conducted with a target 
fit factors of 100 and 500, which qualifies the application of the 
resulting protocols for fit-testing any respirator at those values.

    NIOSH (Ex. OSHA-2007-0007-0016.1), DOD (Ex. OSHA-2007-0007-0021.1), 
AFL-CIO (Ex. OSHA-2007-0007-0015), and Ching-tsen Bien (Ex. OSHA-2007-
0007-0017.1) discouraged application of the Study results to respirator 
types not tested in the Study. NIOSH stated that it is ``unaware of any 
studies or data demonstrating that all respirator types perform 
similarly when being subjected to a fit test,'' and, ``It is 
inappropriate to conclude that a test result applies to more than just 
those types of respirators that were tested.'' Similarly, DOD stated:

    [I]t is not appropriate to apply the study results to other 
types of respirators. * * * There are many types and styles of NIOSH 
approved filtering-facepiece respirators. There is also ongoing 
controversy about fit testing, efficacy and actual protection 
afforded by filtering facepiece respirators given the variation in 
styles within the class. * * * Any change to current QNFT protocols 
that allow filtering facepiece respirators (as a class) to be 
included should be based on actual fit testing data per ANSI Z88.10-
2001 or the current edition.

    Larry Janssen asserted that Class 100 filtering-facepiece 
respirators are the only filtering-facepiece respirators that would be 
appropriate for fit-testing using the revised PortaCount[supreg] QNFT 
protocols (Ex. OSHA-2007-0007-0018.1). Clifton D. Crutchfield 
questioned whether any filtering-facepiece respirators can be 
effectively fit tested with the PortaCount[supreg] N-95 Companion using 
the proposed protocols (Ex. OSHA-2007-0007-0019.1). Dr. Crutchfield 
stated, ``The [N-95] Companion can * * * report fit factors only up to 
200. This obviously precludes the use of Revised PortaCount[supreg] 
Protocol 2.'' Dr. Crutchfield also noted that revised 
PortaCount[supreg] QNFT protocol 1 has an in-mask sampling time of 10 
seconds, which ``allows sampling only about 2 breaths per exercise in 
order to determine an in-mask concentration for that exercise.'' In the 
absence of data demonstrating that the PortaCount[supreg] N-95 
Companion can effectively measure respirator leakage in ten seconds, 
Dr. Crutchfield remarked that ``allowing such fit-testing to occur 
would be neither justified nor prudent.''
    OSHA does not believe that it is appropriate to apply the fit-
testing results to types of respirators not tested in the Study. While 
Mr. Janssen emphasizes the absence of data demonstrating that fit-
testing protocols perform differently on different respirator types, 
OSHA views this lack of information on the consistency of fit-test 
performance as a reason to avoid generalizing from the results of the 
Study. Accordingly, OSHA believes that it would be prudent to validate 
new fit-test protocols using filtering-facepiece respirators because 
filtering-facepiece respirators are the most commonly used respirator. 
(See Table 30, NIOSH-BLS survey, Ex. 6-3, Docket No. H-049C.)
    However, as Dr. Crutchfield and Mr. Janssen note, a question 
remains as to whether filtering-facepiece respirators can be 
effectively fit tested using the revised PortaCount[supreg] QNFT 
protocols. In view of the considerable uncertainty as to the 
consistency of fit-test protocol performance on different respirator 
types, OSHA concludes that the Study did not establish that the revised 
PortaCount[supreg] QNFT protocols will accurately determine fit for N95 
filtering-facepiece respirators.

E. Conclusions

    Based on a complete and thorough review of the rulemaking record, 
OSHA concludes that:

[[Page 4331]]

    1. The Study was not conducted according to accepted experimental 
design practices and principles.
    2. The Study did not properly or fully describe the fit-testing 
results.
    3. The Study did not establish the reproducibility of the results 
generated by the revised PortaCount[supreg] QNFT protocols.
    4. The Study did not demonstrate that the revised 
PortaCount[supreg] QNFT protocols will identify respirators with 
unacceptable fit as effectively as the quantitative fit-testing 
protocols already listed in Part I.C.3 of Appendix A of OSHA's 
Respiratory Protection Standard.
    5. The reported test-sensitivity value of 0.91 indicates that 
revised PortaCount[supreg] QNFT protocol 1 would allow a substantial 
number of employees to pass fit tests with improperly fitting 
respirators compared to a protocol that achieves the 0.95 sensitivity 
value that ANSI Z88.10-2001 lists as a criterion measure for new fit-
testing protocols.
    6. The Study did not demonstrate that the revised 
PortaCount[supreg] QNFT protocols will accurately determine fit for 
filtering-facepiece respirators.
    Additional validation testing of, or revisions to, the revised 
PortaCount[supreg] QNFT protocols may provide new data that demonstrate 
the accuracy and reproducibility of the fit-testing results generated 
by these protocols. OSHA would evaluate any new data and supporting 
documentation received, and, if appropriate, would submit it to the 
public for notice and comment. If the revised protocols are to apply to 
filtering-facepiece respirators, then the resubmission must include 
appropriate fit-testing results for these respirators.

List of Subjects in 29 CFR Part 1910

    Fit testing, Hazardous substances, Health, Occupational safety and 
health, Respirators, Toxic substances.

Authority and Signature

    David Michaels, PhD, MPH, 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: Section 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 January 22, 2010.
David Michaels,
Assistant Secretary of Labor for Occupational Safety and Health.
[FR Doc. 2010-1656 Filed 1-26-10; 8:45 am]
BILLING CODE 4510-26-P