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Comparing Your Exposure to OSHA's Limit |
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There is not one
crystalline silica exposure limit for all cases. Rather, the limit is derived from a
calculation that takes into account the percentage of quartz, cristobalite, tridymite, and
respirable dust specific to your particular work-site.
To determine the limit and
compare it to the actual amount, you can: |
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Follow a written example to make the calculations yourself
or
Let the Advisor Genius do the calculations for you |
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will supply certain data and the Genius will make some calculations to produce three
different number: |
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| PEL |
This number is
the calculated permissible exposure limit for dust to which the worker may be exposed. It
uses the data you supplied and is based on the percent crystalline silica in the sample.
For example: 1.6 mg/m3 |
| Exposure |
This number is
the actual amount of dust that is in your work environment, for example: 4.8 mg/m3 |
| Severity |
This number is
derived by dividing the exposure by the PEL, for example: 4.8 / 1.6 = 3.0
If the
severity number is higher than 1.0 you are above the limit. If the severity number
is less than 1.0 you are below the limit.
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Genius performs calculations for a respirable dust sample. If your sample is collected
as a total dust sample, you will need to make adjustments to the PEL and Severity the
Genius calculates. |
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| Apply Your Knowledge |
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| Permissible Exposure Limit for Crystalline Silica |
| OSHA
regulation 1910.1000 Table Z-3 is used to determine the
exposure limits for crystalline silica. Though this regulation is under the General
Industry Standard, crystalline silica exposures in the Construction and Maritime
Industries are subject to this same limit. Regulating these industries under the General
Industry Standard is specifically addressed in Appendix F of the OSHA Special Emphasis
Program (SEP) for Silicosis. |
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are also limits on coal dust and amorphous silica.
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