Addendum zu N,N‐Dimethylformamid
Beurteilungswerte in biologischem Material
Thomas Göen1Hans Drexler1
Andrea Hartwig2
MAK Commission3
1 Friedrich-Alexander-Universität Erlangen-Nürnberg, Institut und Poliklinik für Arbeits-, Sozial- und Umweltmedizin, Henkestraße 9–11, 91054 Erlangen, Deutschland
2 Institut für Angewandte Biowissenschaften, Abteilung Lebensmittelchemie und Toxikologie, Karlsruher Institut für Technologie (KIT), Adenauerring 20a, Geb. 50.41, 76131 Karlsruhe, Deutschland
3 Ständige Senatskommission zur Prüfung gesundheitsschädlicher Arbeitsstoffe, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Deutschland
Abstract
In 2018, the German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated N,N‐dimethylformamide (DMF) and has derived a biological tolerance value at the workplace (BAT) for different biomarkers. Available new publications regarding the relationship between external and internal exposure are described in detail.
The determination of the sum of N‐methylformamide and N‐hydroxymethyl‐N‐methylformamide in urine at the end of the working shift reflects the exposure of the last hours of a working day. On the contrary, the concentration of the mercapturic acid AMCC (N‐acetyl‐S‐(N‐methylcarbamoyl) cysteine) in urine reflects the cumulative DMF exposure of the last working days. The DMF haemoglobin adduct MCVal can be used as long term parameter and sampling should be carried out at the earliest after several weeks of exposure. Since significant correlations where observed between the DMF concentration in the air and the biomarkers’ concentration in urine and blood for workers not using breathing masks, these data were used to evaluate BAT values in correlation to the present MAK value of 15 mg/m3. In consequence, BAT values of 20 mg NMF (N‐methylformamide plus N‐hydroxymethyl‐N‐methylformamid)/l urine (sampling time: end of exposure or end of shift) and 25 mg N‐acetyl‐S‐(N‐methylcarbamoyl) cysteine/g creatinine (sampling time: end of exposure or end of shift, for long‐term exposures: at the end of the shift after several shifts) were evaluated.
According to currently available information damage to the embryo or foetus cannot be excluded after exposure to concentrations at the level of the MAK and BAT values (pregnancy risk group B). The MAK value documentation indicates that a concentration of 1 ml/m3 (3 mg/m3) would correspond to the classification in Pregnancy Risk Group C. Considering the described correlations between DMF in the air and the biomarkers, this assumption applies for 4.75 mg NMF/l urine, 7.22 mg AMCC/g creatinine as well as 51.4 nmol MCVal/g Globin, considering the corresponding sampling times, respectively.
