Table 2
Periodic Exposure Evaluation Frequencies
| If employee exposure
monitoring results: |
Then: |
| Are between the: |
Conduct additional
exposure monitoring at
least every 6 months. |
| • Action level (AL) of 0.5
parts per million (ppm); |
| AND |
|
| •TWA8 of 1 ppm |
|
| Are above the TWA8; |
Conduct additional
exposure monitoring at
least every 3 months. |
| OR |
| Above the STEL |
|
| Have been obtained at
least every 3 months; |
You may decrease your
evaluation frequency for
the TWA8 to every 6
months. |
| AND |
| Have 2 consecutive
monitoring results, taken at
least 7 days apart, showing
8-hour employee exposure
monitoring results that
have dropped below the
TWA8, but remain at or
above the AL |
|
| Have 2 consecutive
evaluations, taken at least
7 days apart, showing
8-hour employee exposure
monitoring results that
have dropped below the
AL and STEL |
You may stop periodic
exposure evaluations. |