Glossary / Exposure limits
Action level
Action level is an airborne exposure level, usually set below the permissible exposure limit, at which an OSHA standard requires the employer to begin specific activities such as exposure monitoring or medical surveillance. It acts as an early trigger before the legal limit is reached.
Explanation
Action levels appear in OSHA's substance-specific standards, for example those for lead, benzene and formaldehyde, and are typically set at a fraction of the Permissible exposure limit (PEL). The idea is that if exposures are creeping up toward the limit, the employer should start checking and protecting workers before anyone is over it.
What an action level triggers depends on the standard. Common requirements include periodic air monitoring, training, record keeping and medical examinations for workers exposed at or above that level. Staying below it for the required time may allow the employer to reduce or stop certain obligations, but only as the standard permits.
Action levels are measured the same way as the PEL, normally as an 8-hour Time-weighted average (TWA). An action level is not a safe level or a second limit that permits exposure up to the PEL without further steps. If monitoring shows results at or above it, the employer must follow the specific rule.
Do not confuse this with the unrelated use of the term in other contexts, such as spill response triggers or emergency action levels. In exposure control, the action level is a regulatory trigger for a specific chemical standard. The SDS may mention it in Section 8 or Section 15 when a substance-specific standard applies.
What to do and watch for
- Check whether a substance-specific OSHA standard sets an action level for the chemical you use.
- Start monitoring when results approach the action level, not only the PEL.
- Keep exposure monitoring and medical records as the standard requires.
Where it appears on an SDS
- Section 8: Exposure controls / personal protection. Where a specific OSHA standard applies, the exposure limits may note the action level next to the PEL.
- Section 15: Regulatory information. Regulatory information may point to the OSHA standard that creates the action level.
SDS content and wording vary by supplier. This page is general reference and does not replace the current SDS for your product.