The EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF) said the substance does not pose a risk for the consumer (read the full scientific opinion here).
A safety assessment looked at 1,7-octadiene for use as a crosslinking co-monomer in polyolefins at a maximum use level of 0.9%.
CEF said it is not of a safety concern if the substance is only to be used as described above for contact with foods for long term storage at room temperature and including hot fill conditions and its migration does not exceed 0.05 mg/kg food.
There were no residues detectable in the polymer (< 16 μg/kg detection limit) and no detectable migration of the substance itself and its two main impurities into appropriate food simulants (detection limits in the range of 1-8 μg/kg).
Comparative migration test
A comparative migration test between low density polyethylene (LDPE) samples made with and without the substance into 95% ethanol at 10 days/40 °C showed no qualitative difference between the two gas chromatography–mass spectrometry chromatograms (GC-MS).
GC-MS analysis gave complex chromatograms of oligomeric species, from which it was estimated overall migration was considerably lower than the limit of 10 mg/dm².
Based on the negative results of three in vitro tests, the panel considered the substance is not of genotoxic concern.
The safety assessment request was received from the Bundesamt für Verbraucherschutz und Lebensmittelsicherheit, following a corresponding application on behalf of Evonik Industries, Germany.
As the polyolefin oligomers and other reaction products containing the co-monomer are likely to strongly vary in amount and composition, depending on the polymerization and manufacturing process used, they were not evaluated.
Evaluation of these oligomers and reaction products should be conducted on a case by case basis.
The substance is intended to be used as a crosslinking co-monomer in manufacture of all kinds of polyolefin (polyethylenes and polypropylenes) plastics at a maximum level of 0.9%.
Final articles will be used in contact with all types of foodstuffs at frozen and refrigerated conditions up to any long term storage at room temperature and including the hot fill process conditions of 70 °C for two hours or up to 100 °C for up to 15 minutes.
The substance had not been evaluated by the SCF or EFSA in the past.
At a use level of 0.9% taking into account the volatility of the impurities and the high temperature polymer processing conditions as well as their chemical reactivity, the migration of these impurities from the final polymer it is not expected, said the panel.
Specific migration tests from a LDPE sample, produced with 0.9%, were carried out using 3% acetic acid, 50% ethanol, olive oil and poly(2,6-diphenyl-p-phenylene oxide) in all cases for 10 days at 40 °C.
Migration was not found at detection limits in the range of 1–8 μg/kg in food simulant. Also residual content of the substance in the test sample was determined.
The substance was not detectable in the polymer at a detection limit of 16 μg/kg. This indicates that the substance reacts and it is completely incorporated into the polymer network and supports the findings from the specific migration measurements.
Specific migration was also measured for the two main impurities (ethenyl-cyclohexane and 1,3-cycloheptadiene, with migration not detectable at the same detection levels.