The Regulation relating to Limit Values (Grenzwerteverordnung, GKV) defines the maximum permissible values for certain pure substances. These correspond to the maximum allowable concentration of a work substance in the form of gas, vapour or suspended matter in the air at the workplace, which despite repeated and long-term exposure does not impair workers’ health and constitutes no intolerable nuisance. Mixtures subject to MAC values also need to be assessed. A distinction has to be made between MAC values and TAC (technical approximate concentration) values.
