Substances with intense odours: general principles, evaluation and designation
MAK Value Documentation – Translation of the German version from 2023
Christoph van Thriel1 (Head of the working group „Neurotoxicity and Chemosensation“ of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)Christian Monsé2
Albert W Rettenmeier3
Kirsten Sucker2
Sabine Werner4
Edgar Leibold5
Thomas Brüning2
Michael Arand6
Heiko Käfferlein2
Rüdiger Bartsch7
Patricia Kreis7
Andrea Hartwig8 (Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
MAK Commission9
1 Leibniz Research Centre for Working Environment and Human Factors, Ardeystraße 67, 44139 Dortmund, Germany
2 Institute for Prevention and Occupational Medicine of the German Social Accident Insurance (DGUV), Institute of the Ruhr University Bochum (IPA), Bürkle-de-la-Camp-Platz 1, 44789 Bochum, Germany
3 Institute of Medicinal Informatics, Biometry and Epidemiology, University Hospital Essen, Hufelandstraße 55, 45122 Essen, Germany
4 Institute for Occupational Safety and Health (IFA), German Social Accident Insurance (DGUV), Alte Heerstraße 111, 53757 Sankt Augustin, Germany
5 BASF SE, Department FEP/ P, Building Z 570, Carl-Bosch-Str. 38, 67056 Ludwigshafen, Germany
6 Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstraße 190, 8057 Zurich, Switzerland
7 Institute of Applied Biosciences, Department of Food Chemistry and Toxicology, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Building 50.41, 76131 Karlsruhe, Germany
8 Institute of Applied Biosciences, Department of Food Chemistry and Toxicology, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Building 50.41, 76131 Karlsruhe, Germany
9 Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Germany
Abstract
The German Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) evaluated data from literature and databases to identify workplace chemicals with objectionable odour and developed a concept to label relevant substances. Odours from substances at the workplace are often strong, unpleasant and perceptible even at concentrations below the valid MAK values (maximum concentration at the workplace). “Odour-associated symptoms” such as nausea and headaches may develop as a result of a special processing of neurophysiological signals, a specific neuroanatomical connectivity and the evolutionary significance of olfaction. These effects cannot be taken into consideration for the derivation of a MAK value because they occur only in isolated cases. Substances at the workplace that are associated with these kinds of effects are designated in the List of MAK and BAT Values with a corresponding footnote. This article presents the scientific background and the specific procedure used for applying the footnote. By stimulating specialized odour receptors, odours are perceptible even at very low concentrations. After crossing only a few synaptic junctions, the odour information reaches regions of the brain such as the limbic system, the vegetative nuclei of the hypothalamus and the reticular formation. Odours, particularly unpleasant ones, are often perceived as a sign of danger based on individual experiences and evolutionary developments. However, individual responses differ considerably and this variation cannot be explained adequately by physiological mechanisms. Therefore, in order to have the potential of inducing “odour-associated symptoms”, the workplace substances in question must have a low odour threshold and an unpleasant odour quality. The methods used to identify these odour characteristics are quite heterogeneous and have not been standardized. Different sources were used to determine the odour characteristics of the 43 workplace substances from the List of MAK and BAT Values that potentially met these criteria. After the data were checked for plausibility, 23 of the substances were designated with the footnote following a systematic evaluation.
