What Does Action Level (AL) Mean?
Action level (AL) is a term used by the Occupational Safety and Health Administration (OSHA) to indicate that exposure to a harmful physical or chemical agent has reached a level requiring specific risk-mitigating actions, such as exposure monitoring and medical surveillance.
The action level is calculated as an eight-hour time-weighted average and is generally lower than the Permissible Exposure Limit (PEL).
Safeopedia Explains Action Level (AL)
The ALs and PELs of physical or chemical agent are set by OSHA regulations, along with the medical screenings and surveillance measures that must occur at each level of exposure.
Employers may choose to go beyond OSHA's requirements and, instead, use more recent exposure levels provided by the National Institute for Occupational Safety and Health (NIOSH) and the American Conference of Governmental Industrial Hygienists (ACGIH).
OSHAs Listed Action Levels
In industrial hygiene practice, an action level is generally defined as one-half of the PEL, unless otherwise mentioned.
Employers must engage in industrial hygiene monitoring to identify workers who are at risk of exposure to harmful chemicals at or above the action level. Standards for asbestos, beryllium, chromium VI, formaldehyde, lead, and silica all contain PELs. Action levels can also be found for noise exposure.
The action level for hazardous substances is designated in 29 CFR Part 1910 for specific substances.
Determining Employee Exposure
According to OSHA 1910.1450(d), the employee exposure determination includes:
- Initial monitoring – If a workplace uses or houses a substance that requires monitoring, the employer must measure employee exposure to that substance if it routinely exceeds concentrations that would reach the AL - or, in its absence, the PEL
- Periodic monitoring – If initial monitoring reveals employee exposure to AL, the employer must immediately follow the actions required by the relevant standard
- Termination – Monitoring can be terminated in accordance with the relevant standard
- Result notification to employee – The results of the monitoring must be conveyed to the employee within 15 working days of its receipt in writing, either individually or by posting the results where employees can see it
According to OSHA 1910.1450(g)(1)(ii), if exposure monitoring reveals exposure levels that regularly cross over the AL threshold, the employer must initiate medical surveillance for affected employees, as prescribed by the standard.