EFSA approves PVC food can coating additive
The agency said it had no safety concerns over methacrylic acid, 2,3-epoxypropyl ester, copolymer wi…The agency said it had no safety concerns over methacrylic acid, 2,3-epoxypropyl ester, copolymer with acrylic and/ or methacrylic acid alkyl (C1-C4) esters for use as stabiliser for organosol coatings for food cans.
The substance, Ref No 65841 and FCM Substance No 958, can be used as part of a PVC layer for all foodstuffs except beer and beverages, under all conditions of time and temperature including sterilisation followed by long term storage, added the CEF panel of experts.
The food safety body carried out the assessment following a request from the Ministry for Health, Welfare and Sports, the Netherlands. The Dutch agency made the referral after receiving an application from the company The Valspar Corporation, UK.
Migration tests
According to the Valspar, the substance is a polymeric additive made from methacrylic acid, 2,3- epoxypropyl ester - also called glycidyl methacrylate (GMA) - copolymerised with alkyl methacrylate and/or alkyl acrylate (alkyl = C1-C4).
The substance is intended to be used as stabiliser at a level of 10-25 %
“The GMA provides oxirane functionality on an ‘inert’ polymer backbone,” said the CEF report. “This oxirane functionality reacts with (scavenges) any hydrogen chloride generated from the PVC during the thermal processing of the coating, forming corresponding chlorinated species.”
The substance contains an oxirane ring which reacts with – and scavenges - any hydrogen chloride generated from the PVC during the thermal processing of the coating, forming corresponding chlorinated moieties.
Migration and toxicity tests were submitted for a single polymeric additive – known as EMA-GMA (methacrylic acid, 2,3-epoxypropyl ester (GMA) (20 %), copolymer with methacrylic acid, ethyl ester (synonym ethyl methacrylate, acronym EMA) (80%) - which is considered representative of the copolymers of GMA with acrylic and methacrylic acids alkyl (C1-C4) esters.
The migration of residual monomers (EMA, GMA and hydrolysis product of GMA) was not detectable for the stated conditions of use. The migration of low molecular weight oligomers (less than 1000 Da) containing the GMA unit was up to 0.016 mg/6 dm2.
No chlorinated species detected
The oligomeric fraction and the corresponding chlorinated oligomers were tested in three in vitro and two in vivo genotoxicity tests and they were considered as non-genotoxic.
Based on the available results of these tests, the Panel concluded there was no concern with respect to genotoxicity in vivo. The oligomeric fraction was also rested in a 90-day oral study in rat and the ‘no observable adverse effect level’ (NOAEL) of 150 mg/kg b.w. per day was assigned.
SCF assessment
While the substance has not been previously evaluated by the Scientific Committee on Food (SCF) or EFSA , the monomers have been evaluated by the SCF and further authorised by the European Commission for use in the manufacture of food contact plastics.
GMA (REF. No 20590, FCM Substance No 220) was classified in SCF list 4B (EC, 1999) and is included in Regulation (EU) No 10/20114 (EC, 2011) with a restriction of QMA = 0.02 mg/6 dm². At that time, the SCF highlighted the classification of GMA as an additive in PVC organosols.
