UV light describes the part of the light spectrum between 10 and 400nm. As such, UV light has a relatively high energy level, which may be harmful to materials. As food contact materials are often exposed to solar UV light, UV filters are added to the polymer material to prevent degradation. UV filters are used to prevent both, the rapid degradation of the food packaging material and/or the food stuff contained within. Some UV filters act as UV screens absorbing the harmful UV light. They are opaque and protect both food as well as the packaging material. Other UV screens are based on organic compounds and act as ultraviolet degradation inhibitors (p.38,[1]).

Apart from being used in polymer based materials, UV filters are added to printing inks. Here they act as photo initiators, which start the reaction that eventually dries the ink rapidly and prevents set off effects of other substances contained in ink into the food [2]. However, they themselves may leach into the food stuff [3].

Leaching of UV-screens both from printing inks as well as polymers has been observed [3-5]. Some of these chemicals have also been tested for their effect on the human organism, in vitro or in vivo. Of particular concern are chemicals that have high production volumes as defined by the OECD (Organisation of Economic Cooperation and Development). Such substances are produced in quantities larger 1000 tonnes/year [6].

The following UV screens have been measured in food stuffs and are produced in quantities larger 1000 tonnes/year:

In polymers:

  • 2-(2H-benzotriazol-2-yl)-4-methyl-phenol (CAS 2440-22-4) showed estrogenic activity in Yeast Two-Hybrid Assay [7] and in the Estradiol receptor ELISA assay [8]
  • Bumetriziole (CAS 3896-11-5) showed estrogenic activity in Yeast Two-Hybrid assay [7], a slight increase in the proportion of foetuses with
  • incomplete ossification of sternebrae at a dose level of 3000 mg/kg bw/day in mice (repro tox study, OECD, report 2010), irritating to the eye, contact sensitizer (New Zealand EPA)
  • 2,4-bis(1,1-dimethylethyl)-phenol, phosphite (3:1) (CAS 31570-04-4) showed estrogenic activity in Yeast Two-Hybrid assay [7]

In paper and board (printing inks):

  • Benzophenone (CAS 119-61-9) showed positive responses in uterotrophic assay testing estrogenic activity [9]

References

1.         Crompton, T.R., Additive Migration from Plastics into Foods. A Guide for Analytical Chemists. 2007, Shawbury, Shrewsbury, Shropshire, UK: Smithers Rapra Technology Limited.
http://books.google.ch/

2.         Aurela, B., KCL finland, Sjöderhelm, L., Food packaging inks and varnishes and chemical migration into food, in Chemical migration and food contact materials. 2007, Woodhead Publishing ltd.: Abington. p. 302-319.
http://firatozel.files.wordpress.com/2011/09/chemical_migration_and_food_contact_materials.pdf.

3.         Bradley, E.L., et al., Printing ink compounds in foods: UK survey results. Food Additives and Contaminants: Part B, 2012:1-11.
http://dx.doi.org/10.1080/19393210.2012.725774.

4.         Begley, T.H., et al., Migration of a UV stabilizer from polyethylene terephthalate (PET) into food simulants. Food Addit Contam, 2004. 21(10):1007-1014.

5.         Monteiro, M., C. Nerin, and F.G. Reyes, Determination of UV stabilizers in PET bottles by high performance-size exclusion chromatography. Food Addit Contam, 1996. 13(5):575-586.
http://www.ncbi.nlm.nih.gov/pubmed/8799719.

6.         OECD, Procedures, including the use of electronic discussion groups and the on-line OECD existing chemicals database., in Manual for hte Assessment of Chemicals. 2012, OECD.
http://www.oecd.org/env/chemicalsafetyandbiosafety/assessmentofchemicals/Chapter1_17%20September%202012.pdf.

7.         Ogawa, Y., et al., Estrogenic activities of chemicals related to food contact plastics and rubbers tested by the yeast two-hybrid assay. Food Addit Contam, 2006. 23(4):422-430.

8.         Morohoshi, K., et al., Estrogenic activity of 37 components of commercial sunscreen lotions evaluated by in vitro assays. Toxicology in Vitro, 2005. 19(4):457-469.
http://www.sciencedirect.com/science/article/pii/S0887233305000111.

9.         Suzuki, T., et al., Estrogenic and antiandrogenic activities of 17 benzophenone derivatives used as UV stabilizers and sunscreens. Toxicology and Applied Pharmacology, 2005. 203(1):9-17.
http://www.sciencedirect.com/science/article/pii/S0041008X04003539.