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Introduction to SDS occupational exposure limits

Posted Date:2023/12/8

1. occupational exposure limits; OELs

Repeated exposure of workers to one or more occupational harmful factors over a long period of time in the course of occupational activities will not cause adverse health effects of the majority of the exposure level. The occupational exposure limits of chemical hazardous factors are divided into three categories: time-weighted average permissible concentration, short-term permissible concentration and maximum permissible concentration.

2. permissible concentration-time weighted average; permissible concentration-time weighted average; PC-TWA

The average allowable exposure concentration for 8 h working days and 40 h working weeks with time as the weight.

3. permissible concentration-short term exposure limit；PC-STEL

Under the premise that the actual measured average exposure concentration of 8 h working days and 40 h working weeks complies with PC-TWA, the weighted average exposure concentration of workers for a short period of time (15 min) is allowed.

4. maximum allowable concentration；MAC

In one working day, at any time, the concentration of chemical harmful factors should not be exceeded.

5. peak exposures；PE

The maximum or peak concentration of a particular substance in the air determined over the shortest analyzable time period (no more than 15 minutes). For exposure to chemical hazards that have PC-TWA but have not yet formulated PC-STEL, short exposures should be controlled using peak exposure concentrations. Subject to PC-TWA compliance, the maximum exposure to PC-TWA levels is allowed to occur for any short period of time (15 min) during a working day.

The main function of occupational exposure limits is to protect the occupational health and safety of workers and prevent health damage caused by long-term exposure to occupational harmful factors. Through the formulation and implementation of occupational exposure limits, enterprises and workers can be guided to reasonably control and reduce the exposure to occupational harmful factors, and reduce the risk of occupational diseases. At the same time, the occupational exposure limit also provides the basis and standard for government departments and professional organizations to carry out occupational health supervision.