Limit Values Germany - MAK

MAK values are derived by the “DFG Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area”, better known as the “MAK Commission”. This independent body has been mandated by the German Research Foundation (DFG) to determine the current state of research relating to the health risks posed by substances and materials used at the workplace, and to advise public authorities accordingly.

Members are appointed ad personam in their capacity as authoritative experts and not as representatives of the institutions or companies in which they work. Scientists and other experts from public authorities can be appointed as permanent guest contributors with an advisory function. However, in order to avoid a possible conflict of interest, the latter have no voting rights. In discussions and decision-making, only scientific arguments regarding health at the workplace are considered. Other aspects such as competitive socio-political, economic or technological reasons are excluded.

The most important practical results of the Commission’s work are scientific recommendations for the establishment of MAK values (maximum workplace concentrations) and BAT values (biological tolerance value for occupational exposure), for the classification of carcinogenic, embryotoxic/fetotoxic substances and germ cell mutagens, and for the evaluation of measurement methods.

The MAK value is defined as the maximum concentration of a chemical substance (a gas, vapour or particulate matter) in the workplace air which generally does not have known adverse effects on the health of employees nor causes unreasonable annoyance (e.g. by nauseous odour), even when a person is repeatedly exposed during long periods, usually for 8 hours daily but assuming on average a 40-hour working week. Known effects of a substance in man are given highest priority in the derivation of the MAK value, which is based on the “no observed adverse effect level” (NOAEL) for the most sensitive effect with relevance to health. If a NOAEL cannot be derived from the available data, a MAK value is not established.

Detailed scientific documentation of each decision is published in the loose-leaf collection entitled “Toxikologisch-arbeitsmedizinische Begründungen von MAK-Werten”, also available in English in the “Occupational Toxicants” series. Prospective changes and new entries are announced each year in the “List of MAK and BAT Values”, in the periodical “Zentralblatt für Arbeitsmedizin”, and in the Joint Ministerial Gazette (Gemeinsames Ministerialblatt).

Once a year, the current results of the Commission’s proposals are forwarded to the German Federal Minister of Labour and Social Affairs. With substantial support from the Committee on Hazardous Substances (Ausschuss für Gefahrstoffe – AGS), the Ministry examines the recommendations in the light of the requirements of the German Hazardous Substances Ordinance, and makes them legally binding in an appropriate form – amended or unchanged – as a basis for occupational health protection.

September 2012