On July 18, 2017 the European Food Safety Authority’s (EFSA) Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF Panel) published a scientific opinion on the safety assessment of dimethyl carbonate (CAS 616-38-6). The substance is intended to be used as a monomer in the manufacture of “a polycarbonate prepolymer with 1,6-hexanediol and then reacted with 4,4′-methylenediphenyldiisocyanate (MDI) and diols, such as polypropylene glycol and 1,4-butanediol, to form a thermoplastic polyurethane containing 29% of the polycarbonate prepolymer.” Articles made of this polymer are intended for repeated use with short-term contact (up to 30 minutes) at room temperature, for types of food simulated by 10% ethanol and 3% acetic acid.

Overall migration was lower than 2 mg/dm2 in the third migration test conducted at 40° C for 30 minutes. Complete migration of residual dimethyl carbonate would have been less than 1.5 μg/kg food, the CEF Panel explained. Two cyclic hexanediol carbonate oligomers migrated below 50 μg/kg food in the third migration test; all other oligomers migrated below 1 μg/kg food. Three in vitro genotoxicity studies (gene mutation, structural and numerical chromosome aberrations) were considered negative by the CEF Panel. Also, the oligomers detected in the migration tests were considered of no concern for genotoxicity. Therefore, the CEF Panel concluded that dimethyl carbonate is safe in the specified application. When used for other polycarbonates and/or under different conditions, “the migration of dimethyl carbonate and the total polycarbonate oligomers below 1,000 Da is of no safety concern, if each of them does not exceed 0.05 mg/kg food,” the CEF Panel noted.

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CEF (July 18, 2017). “Safety assessment of the substance dimethyl carbonate for use in food contact materials.EFSA Journal 15(7):4901.

Chemical Watch (July 25, 2017). “EFSA publishes opinion on dimethyl carbonate use in FCMs.