Workplace Exposure Limits
Workplace exposures limits are intended to protect workers from excessive exposure to toxic chemicals in the workplace. These limits typically incorporate safety margins to ensure that workers won't be overexposed to hazardous chemicals. Generally, employers must ensure that these limits are not exceeded.
The most common workplace limits are:
- IDLHs (Immediately Dangerous to Life and Health limits)
- TLVs (Threshold Limit Values)
- RELs (Recommended Exposure Limits)
- PELs (Permissible Exposure Limits)
Emergency Response Situations
Using workplace exposure limits to assess a chemical release where the public is (or may be) exposed is not recommended because:
- Workplace limits are designed to protect healthy, adult workers. Because age, health, and exertion influence how susceptible people will be to a pollutant, it's possible that some workplace limits may underestimate risk to the sensitive portions of the general population (such as old, sick, or young people).
- Some workplace limits are designed to protect workers from long-term, repeated exposure to chemicals over the course of a working lifetime—which is very different than protecting people from a single exposure during an emergency situation.
Instead, you should use public exposure guidelines (such as AEGLs, ERPGs, TEELs, and PACs).