Safety assessment of the substance 1,2,3,4-tetrahydronaphthalene-2,6-dicarboxylic acid, dimethyl ester for use in food contact materials

Abstract

This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing aids (CEF Panel) deals with the safety assessment of 1,2,3,4-tetrahydronaphthalene-2,6-dicarboxylic acid, dimethyl ester (TDCM) for use as a co-monomer to manufacture polyester layers. The polyester layer is not intended to be in direct contact with food. The finished multilayer articles are intended for packaging aqueous, acidic and low alcoholic foodstuffs. Contact conditions include sterilisation followed by long-term storage at room temperature. No thermal degradation of TDCM is expected during the manufacture of the middle polyester layer and of the multilayer articles. Total mass transfer of the substance from a polyester monolayer was calculated to be up to 0.032 mg/kg food. Based on three in vitro genotoxicity tests, the CEF Panel considered that the substance does not raise concern for genotoxicity. When tested behind a polypropylene layer, migrating TDCM-related oligomers, their oxidation products and other related reaction products were identified. The major components were TDCM dimers. When tested behind a cyclo-olefin polymer layer, none of the TDCM-related substances were found to migrate. Based on the lack of genotoxicity of the co-monomer, the ester nature of the oligomers and on (quantitative) structure-activity relationship ((Q)SAR) analysis, the CEF Panel considered that there is no indication of genotoxicity for the oligomers, their oxidation products and other TDCM-related reaction products. The CEF Panel concluded that the substance is not of safety concern for the consumer if used as a co-monomer for the manufacture of a polyester layer intended to be used as an inner (non-food contact) layer of a multilayer material for contact with foods simulated by simulants A, B, C, D1 (as set in Regulation (EU) 10/2011). The migration of the sum of the substance and the dimers (cyclic and open chain) should not exceed 0.05 mg/kg food.

Keywords: 1,2,3,4‐tetrahydronaphthalene‐2; 6‐dicarboxylic acid; CAS No 23985‐75‐3; FCM substance No 1066; dimethyl ester (TDCM); food contact materials; monomer; polyester; safety assessment.