Benzene Monitoring: Technical aspects of the OEL proposal of 0.05ppm
If the benzene OEL is lowered as recommended by RAC, the petroleum industry would need to consider:
1. Monitoring methods should target a lower OEL and therefore must be updated accordingly.
2. The number of samples needed for the survey will be higher. With an OEL of 160 μg/m3 a statistical approach is probably needed to demonstrate compliance and therefore at least 6 measurements for each Similar Group of Exposure (SEG) of workers will be needed.
3. The frequency of measurements might increase depending on the results of the surveys. It might be necessary to repeat the measurements after 12 months if the Geometric Mean (GM) of the distribution is 1/2 of the OEL.
4. Exposure from non-occupational sources in exposure evaluation should be considered.