Benzoic acid and alkali benzoates
MAK Value Documentation, addendum – Translation of the German version from 2017
Andrea Hartwig1 (Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)MAK Commission2
1 Institute of Applied Biosciences, Department of Food Chemistry and Toxicology, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Building 50.41, 76131 Karlsruhe, Germany
2 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 Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated benzoic acid and alkali benzoates [65‐85‐0; 532‐32‐1; 582‐25‐2] to derive a maximum concentration at the workplace (MAK value), considering all toxicity endpoints. Available study reports and publications are described in detail.
Based on the NOAEC for lung toxicity of 12.6 mg/m3 in a 4‐week inhalation study in rats, a MAK value of 0.5 mg/m3 for the strongly irritating benzoic acid has been derived. Alkali benzoates are only slightly irritating. In consideration of the systemic NOAEC of 250 mg/m3 in another 4‐week inhalation study in rats exposed to benzoic acid, a MAK value for alkali benzoates of 10 mg/m3 (inhalable fraction), calculated as benzoate, has been derived. Benzoic acid and alkali benzoates are assigned to Peak Limitation Category II, because systemic effects are critical, and excursion factors of 2 for alkali benzoates and of 4 for benzoic acid are set.
In a developmental toxicity study with sodium benzoate in rats, foetotoxic effects were observed at 1850 mg/kg body weight and day. The NOAEL was 1340 mg/kg body weight and day. In mice, rabbits and hamsters, no developmental toxicity from sodium benzoate was detected in the foetuses of dams treated with up to 175, 250 or 300 mg/kg body weight and day, respectively. The differences between the NOAEL for rats, mice, rabbits and hamsters scaled to an inhalation concentration at the workplace and the MAK value are considered so large that damage to the embryo or foetus is unlikely when the MAK value is observed. Therefore, benzoic acid and alkali benzoates are classified in Pregnancy Risk Group C.
Benzoic acid and alkali benzoates are not regarded as genotoxic. Long‐term studies with sodium benzoate in rats and mice were of limited validity and do not point to a carcinogenic potential. Sensitization is not expected as benzoic acid and alkali benzoates are not contact sensitizers in animal studies. Immediate contact reactions observed in animals and humans are based on a non‐immunologic mechanism. Skin contact is expected to contribute significantly to the systemic toxicity. Therefore, benzoic acid and alkali benzoates are designated with an “H”.
