OELs: Occupational Exposure Limits

Occupational Exposure Limits (OELs) is a term used to represent the:
(1) Concentration or intensity of an airborne agent that is allowable
(2) Time period over which workplace concentrations are averaged to compare with allowable exposure
(3) Allowable concentration of a biological exposure index (BEI) in a biological sample

Biological Exposure Indicies (BEI)®

BEI are values used for guidance to assess biological monitoring results. With respect to chemical exposure, biological monitoring is the measurement of the concentration of a chemical marker in a human biological media that indicates exposure.

Tank Farm OELs

For work at Hanford's tank farms, the most protective OELs have been selected for use from Department of Energy (DOE) regulated limits (e.g., OSHA permissible exposure limits [PELs], ACGIH Threshold Limit Values [TLVs]®, specific DOE regulation) or, in absence of a DOE regulated limit, through a collaborative process of industrial hygienists, workers, and toxicologists.