An article published on July 20, 2018 in the EFSA Journal reported on the safety assessment of poly((R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate) (CAS 147398-31-0) for use in food contact materials (FCMs) with dry or solid food. The assessment was carried out by the Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF Panel) of the European Food Safety Authority (EFSA).

The assessed substance is a “biodegradable (co)polymer . . .  produced by fermentation of palm oil using a genetically modified microorganism.” After migration into food simulant E (Tenax) for 10 days at 40°C or 60°C, no oligomers were detected at the detection limit of 5 µg/kg food. Migration of the degradation product crotonic acid (CAS 107-93-7) was detected at “8 and 25 µg/kg at the two test temperatures, respectively.” The specific migration limit (SML) for crotonic acid of 0.05 mg/kg food is thus not exceeded. There were also “other migrating substances detected,” whose identity and migrating concentrations were not revealed. These substances are said to be “likely originated from or . . . related to the authorized substance . . . ‘palm oil and/or palm fatty acid distillate’ used as carbon source for the fermentation.” CEF Panel states that “at the migration levels reported, these migrants do not give rise to safety concern.”

Among the migrating substances, “the fraction below 1 000 Da is 0.5%,” the CEF Panel further informs. Genotoxicity data was not requested for the assessed substance “because of its high molecular weight.” Both the major and minor monomeric units in the copolymer are also not considered genotoxic.

The CEF Panel concludes that the assessed substance “is not of safety concern if used alone or in blends with other polymers for contact with dry/solid food.”

Read more

CEF (July 20, 2018). “Safety assessment of the substance poly((R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate) for use in food contact materials.EFSA Journal 16(7): e05326.