Dibenzoylperoxid
MAK-Begründung, Nachtrag
Andrea Hartwig1 (Vorsitz der Ständigen Senatskommission zur Prüfung gesundheitsschädlicher Arbeitsstoffe, Deutsche Forschungsgemeinschaft)MAK Commission2
1 Institut für Angewandte Biowissenschaften, Abteilung Lebensmittelchemie und Toxikologie, Karlsruher Institut für Technologie (KIT), Adenauerring 20a, Geb. 50.41, 76131 Karlsruhe, Deutschland
2 Ständige Senatskommission zur Prüfung gesundheitsschädlicher Arbeitsstoffe, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Deutschland
Abstract
The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) summarized and re-evaluated the data for dibenzoyl peroxide [94-36-0] to derive an occupational exposure limit value (maximum concentration at the workplace, MAK value) considering all toxicological end points. Relevant studies were identified from a literature search and also unpublished study reports were used. Dibenzoyl peroxide is at most mildly irritating to the skin of rabbits, but highly irritating to the rabbit eye. Eye irritation is the critical effect of the substance. Studies with repeated inhalation exposure to dibenzoyl peroxide are not available. Therefore, data for benzoic acid, the hydrolysis product of dibenzoyl peroxide, are used for the evaluation. Dibenzoyl peroxide is converted only slowly to benzoic acid, which is a much stronger eye irritant than dibenzoyl peroxide. Taking this into account as well as the maximum concentration at the workplace (MAK value) of 2 mg/m3 established for benzoic acid, a MAK value of 4 mg/m3 has been set for the inhalable fraction of dibenzoyl peroxide. Due to the immediate onset of the eye irritation, the substance has been assigned to Peak Limitation Category I. An excursion factor of 2 has been derived by analogy to benzoic acid. Again, on the basis of the data for benzoic acid, a MAK value of 1 mg/m3 has been derived for the respirable fraction and the substance has been assigned to Peak Limitation Category II with an excursion factor of 4. Damage to the embryo or foetus is unlikely if the MAK value is not exceeded. Thus, dibenzoyl peroxide has been assigned to Pregnancy Risk Group C. Studies investigating the genotoxic potential of dibenzoyl peroxide found increased levels of (oxidative) DNA damage in vitro and in vivo, but no clastogenic or mutagenic effects. The tumour-promoting effects of dibenzoyl peroxide that were observed on the skin of mice and hamsters are of no relevance for humans. There is no evidence of carcinogenic effects after oral or dermal exposure of rats and mice. Despite extensive clinical use of dibenzoyl peroxide as a topical treatment for acne, no cases of substance-related skin cancer in humans have been reported. Dermal absorption is not expected to contribute significantly to systemic toxicity. Although the results of new approach methodologies and animal studies suggest that dibenzoyl peroxide has sensitizing potential, there is still no reliable evidence of an increased risk from occupational exposure. There are no data for respiratory sensitization.
