Airborne chemical concentration limits believed to be safe for most workers.
Maximum allowable concentrations of toxic substances in workroom air for workers.
established concentrations which, if not exceeded, will not generally cause adverse effects to the worker exposed. Exposure limits differ in name and meaning depending on origin. For example:- The exposure levels for the hazardous chemicals that are included in the Regulation respecting the Control of Exposure to Biological or Chemical Agents - made under the Occupational Health and Safety Act of Ontario, are expressed as follow: - TWAEV Time-Weighted Average Exposure Value: The average airborne concentration of a biological or chemical agent to which a worker may be exposed in a work day or a work week. STEV Short Term Exposure Value: - The maximum airborne concentration of a chemical or biological agent to which a worker may be exposed in any 15 minute period, provided the TWAEV is not exceeded.
Concentrations of substances (and conditions) under which it is believed that nearly all workers may be repeatedly exposed day after day without adverse health effects. ACGIH limits are called TLV and OSHA exposure limits are called PEL.
established concentrations which, if not exceeded, will not generally cause adverse effects to the worker exposed. Exposure limits differ in name and meaning depending on origin. For example:- Permissible Exposure Levels are legally enfoceable exposure limits, set by OSHA. PELs are not available for all chemicals. Different exposure limits include: TWA Time-Weighted Average: The average airborne concentration of a biological or chemical agent to which a worker may be exposed in a work day or a work week. STEL Short Term Exposure Level: - The maximum airborne concentration of a chemical or biological agent to which a worker may be exposed in any 15 minute period, provided the TWAEV is not exceeded.
The concentration in workplace air of a chemical deemed the maximum acceptable. This means that most workers can be exposed at given levels or lower without harmful effects. Exposure limits in common use are: TLV-TWA: Threshold limit value—time-weighted average. STEL: Short-term exposure limit. Ceiling value.
