Triglycerides (lard oil, palm oil, rapeseed oil, soybean oil)
MAK Value Documentation – Translation of the German version from 2022
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 Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) summarized and evaluated the data for oils consisting of triglycerides (lard oil [8016‑28‑2], palm oil [8002-75-3], rapeseed oil [8002-13-9], soybean oil [8001-22-7]) 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. The term “triglycerides” refers to mixtures of fatty acid triglycerides, i.e. oily extracts of plant or animal origin. These mixtures are all UVCB substances (substances of Unknown or Variable composition, Complex reaction products or Biological materials). As in the case of white mineral oil, inhalation of the aerosol of poorly water-soluble triglycerides may result in lung overload, inflammatory reactions and microgranulomas. To prevent these overload effects, a MAK value of 5 mg/m3 has been derived for the respirable fraction in analogy to white mineral oil and Peak Limitation Category II with an excursion factor of 4 has been set. There are no prenatal developmental toxicity studies of triglycerides that were carried out according to valid test guidelines. The expected levels of intake after inhalation and dermal exposure to triglycerides at the MAK value of 5 mg/m3 are several orders of magnitude lower than the levels after dietary intake and remain below the recommended daily intake for fats, one of the main components of human nutrition. On the basis of their structure, the fatty acids that form as the degradation products are not expected to induce teratogenic effects. Secondary effects on the foetus due to maternal hypoxia caused by a lung overload are not expected when the MAK value of 5 mg/m3 is observed. Therefore, triglycerides have been assigned to Pregnancy Risk Group C. Triglycerides are not genotoxic. Rapeseed oil did not induce tumours in a carcinogenicity study in rats at a dose of 4100 mg/kg body weight and day. The chemical structures of the triglycerides do not raise concerns of a carcinogenic potential. Refined triglycerides show no indication of a sensitizing potential. Crude unrefined rapeseed oil and soybean oil need to be evaluated separately as their sensitizing potential may be influenced by significantly higher levels of proteins. Skin contact is not expected to contribute significantly to systemic toxicity.
