A term used by ACGIH to express the airborne concentration of a material to which nearly all persons can be exposed day after day without adverse effect. ACGIH expresses TLV's in three ways; TLV-TWA, TLV-STEL, and TLV-CL. TLV's are reviewed and revised annually where necessary by the ACGIH. If a TLV is exceeded, a potential health hazard exists and corrective action is necessary. Also see "Skin" relative to TLV's.
Go to Process Safety Glossary