TLV’s are measures of safe toxic exposure levels, as determined by the American Conference of Governmental Industrial Hygienists (ACGIH). They are time-weighted average concentrations in air that cannot be exceeded without adverse effects for workers in a normal 8-hour work day and a 40-hour work week. TLV’s are updated annually by the ACGIH. This data uses 1996 values.
All TLV’s units are in milligrams per cubic meter. In cases where no TLV measurement is provided for a chemical, it is because no guideline had been provided by the ACGIH. Also please note that not all toxics are released by plants in all sectors, so that for a particular toxic, the omission of a sector row implies zero output of the toxic from that sector.