Occupational Exposure Limits (OELs) are normally averaged over an 8-hour workday and serve to protect against acute and chronic health effects.

Since 2013, the development of Workplace Environmental Exposure Levels (WEELs®) has been managed by the nonprofit organization Toxicology Excellence for Risk Assessment (TERA)​. Click on the OARS-WEEL web page to access all values. Values are listed as either AIHA (if developed before 2013) or OARS (if developed since then).

Questions? Contact TERA by completing the web submission form found on the bottom of this page.