Migration assessment and the ‘threshold of toxicological concern’ applied to the safe design of an acrylic adhesive for food-contact laminates

ABSTRACT

The suitability of an acrylic adhesive used on food packaging was studied. Six potential migrants were identified using GC-MS and UPLC-QTOF. Five compounds were intentionally added (2-butoxyethanol and 2,4,7,9-tetramethyl-5-decyne-4,7-diol 10 (TMDD) and TMDD ethoxylates). One of the compounds identified as 2-(12-(methacryloyloxy) dodecyl)malonic acid was a non -intentionally added substance (NIAS), which could be a methyl metacrylate derivative. A migration study from multilayers containing paper–adhesive–film was carried out. The films used were polyethylene (PE), polypropylene, polyethylene terephthalate, polylactic acid (PLA) and Ecovio F2223®, which is a mixture of biodegradable polyester with PLA. All the non-volatile compounds, including the identified NIAS, migrated into the dry food simulant Tenax ®. Five surfactants based on TMDD were found to migrate from all laminates into Tenax at levels from 0.05 to 0.6 mg kg^–1. The results showed that the lowest migration (0.01 mg kg^–1 for 2-(12-(methacryloyloxy)dodecyl)malonic acid to 0.07 for TMDD mg kg^–1) occurred when the compounds passed through PLA, demonstrating its functional barrier properties to these compounds. In contrast, PE showed the worst barrier properties to these compounds. To evaluate the migration results, the threshold of toxicological concern strategy was applied. The migration values of the surfactant identified were above 0.09 mg kg^–1. Thus, it was decided to remove this surfactant from the formulation.

KEYWORDS:

• NIAS
• food-contact material
• adhesive
• migration
• risk assessment

Acknowledgments

The authors acknowledge Samtack (Barcelona, Spain) for the samples supplied for this work.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Gobierno de Aragón and FOndo Social Europeo [grant number Grupo GUIA T-10]. Also the authors acknowledge Samtack for partial finance of the research. The UPLC-QTOF equipment was acquired with the help of FEDER funds.