In a research article published online on July 31, 2021, in the peer-reviewed journal Science of the Total Environment, Yuuta Sakuragi from the Health Sciences University of Hokkaido, Japan, and co-authors assessed the concentrations of nine widely used benzotriazole UV stabilizers (BUVSs) in plastic food contact materials (FCMs) and the endocrine-disrupting effects of 13 BUVSs, including those first nine.
The scientists purchased polyethylene (PE) and polypropylene (PP) based consumer plastics at Japanese retailers, comprising ten beverage bottle caps, four food packaging articles, and four shopping bags. After extracting the plastic products with the non-polar solvent hexane for 24 h at 40°C, they used gas chromatography – mass spectrometry (GC-MS) for targeted analysis of BUVSs. For 13 BUVSs they also assessed the agonistic and antagonistic activities at the human estrogen (ERα/β) and androgen receptors (AR) using CHO-K1 cell-based transactivation assays.
Out of the nine UV stabilizers Sakuragi et al. tested, they detected eight in the analyzed plastic products. 2-(2-hydroxy-5-methylphenyl) benzotriazole (UV-P, CAS 2440-22-4), 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole (UV-326, CAS 3896-11-5), and 2-(5-tert-butyl-2-hydroxyphenyl) (UV-PS, CAS 3147-76-0) were present at the highest levels, reaching concentrations up to 209 ng/g, 234 ng/g, and 30 ng/g, respectively. The authors also reported that some BUVSs seemed to be specific to certain products, for instance, UV-P and UV-326 were identified in PP and PE bottle caps of all brands analyzed. The four food packages all made of PP generally contained fewer BUVSs but UV-9 was present in all tested polyolefin food packages.
While previous studies have reported on the migration of UV stabilizers from plastic FCMs (FPF reported), Sakuragi and colleagues are the first to analyze endocrine-disruptive effects of BUVSs via the human ERβ-receptor. Of the 13 tested UV stabilizers, four showed ERα and/or ERβ agonistic activity, four ERα and/or ERβ antagonistic activity, and two AR antagonistic activity. In particular, 2-(3-allyl-2-hydroxy-5-methylphenyl)-2H-benzotriazole (UV-P, CAS 2170-39-0) agonized the ERα/β and antagonized the AR. One of the UV-stabilizers that antagonized the ERβ was 2-(3,5-di-tert-amyl-2-hydroxylphenyl)benzotriazole (UV-328; CAS 25973-55-1) which previous studies have linked to endocrine-disrupting effects, liver damage, and kidney damage (FPF reported). In January 2021, UV-328 was further found to fulfill all Persistent Organic Pollutant (POP) criteria under the Stockholm Convention (FPF reported).
The authors conclude “that BUVSs are used regularly as plastic additives and are persistently present in daily products used unconsciously by the population” and that “several of them have endocrine-disrupting effects.”
UV filters are added to the plastic packaging to prevent rapid degradation of the packaging material and/or the foodstuff.
Sakuragi, Y., et al. (2021). ”An analytical survey of benzotriazole UV stabilizers in plastic products and their endocrine-disrupting potential via human estrogen and androgen receptors.” Science of the Total Environment. DOI: 10.1016/j.scitotenv.2021.149374