Atmospheric
testing is required for two distinct purposes: evaluation of the
hazards of the permit space and verification that acceptable conditions
exist for entry into that space. |
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1.
Evaluation Testing
The atmosphere of a confined space should be analyzed using equipment
of sufficient sensitivity and specifically to identify and evaluate
any hazardous atmospheres that may exist or arise, sot that appropriate
permit entry procedures can be developed and acceptable entry
conditions stipulated for that space. Evaluation and interpretation
of these data and development of the entry procedure should be
done by, or reviewed by, a technically qualified professional
(e.g. OSHA consultation service, or certified industrial hygienist,
registered safety engineer, certified safety professional) based
on evaluation of all serious hazards. |
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2.
Verification Testing
The atmosphere of a permit space which may contain a hazardous
atmosphere should be tested for residues of all contaminants identified
by evaluation testing using permit specified equipment to determine
that residual concentrations at the time of testing and entry
are within the range of acceptable entry conditions. Testing order
should be oxygen, flammables, and then toxics. Results of testing
(i.e. actual concentration) should be recorded on the permit in
the space provided adjacent tot the stipulated acceptable entry
condition. |
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3.
Duration of Testing
Measurement of values of reach atmospheric parameter should be
made for at least the minimum response time of the test instrument
specified by the manufacturer. |
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4.
Testing Stratified Atmospheres
When monitoring for entries involving a descent into atmospheres
which may be stratified, the atmospheric envelope should be tested
at a distance of approximately four feet (1.22 meters) in the
direction of travel and to each side. If a sampling probe is used,
the entrants’ rate of progress should be slowed to accommodate
the sampling speed and detector response. |
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5.
Periodically Retest
Retesting verifies that the atmosphere remains within acceptable
entry conditions. |
Notes:
1. Title 29 Code of Federal Regulations 1910.146, Appendix B.
2. 29 CFR 1910.146 (c)(5)(ii)(C) and (d)(5)(iii)
3. 29 CFR 1910.146 (c)(5)(ii)(F) and (d)(5)(ii) |
| This
information is provided “as is” and is not to be considered
a warranty of product performance or as an authoritative informational
page. Due to the diverse field conditions and other variables which
can affect a product’s performance, Calolympic Safety disclaims
all warranties (expressed and implied) as to any product’s
performance or any information provided. |
