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, Flame Tamers disclaims all
warranties (expressed and implied) as to any product’s performance
or any information provided. |
