Threshold Limit Value-Time-Weighted Average (TLA-TWA)
Threshold Limit Value-Time-Weighted Average (TLA-TWA) :
The time-weighted average concentration for a normal eight hour work day or 40-hour work week to which nearly all workers may be exposed, day after day, without adverse effect. (to be superseded by the term Control Limit)
Working Party of the Engineering Practice Committee of the Institution of Chemical Engineers, Nomenclature for Hazard and Risk Assessment in the Process Industries, Rugby, UK 1982. http://cn.manganese.org/images/uploads/pdf/NOMENCL ATURE_OFR_HAZARD_AND_RISK_ ASSESSMENT_IN_THE_PROCESS_INDUSTRIES.pdf, (Nomenclature for Haz and Rsk Assess in the Procss Ind - Brit) {998}