On March 13, 2013, Spanish and German scientists reported on the migration of bisphenol A (BPA) and benzylbutyl phthalate (BBP) from Tritan™ plastic in the scientific peer-reviewed journal Food Chemistry (Guart et al. 2013). The study investigated migration from Tritan™ water containers intended for repeated use, purchased in the European Union. The researchers detected BPA (around 0.030 µg/kg) in the overall first migrate from reuseable Tritan™ 1L water bottles and Tritan™ 19L carboys (for water coolers). In the second and third migration tests, BPA levels were no longer detectable (Limit Of Detection (LOD) of 0.016 µg/kg). BBP (CAS 85-68-7) was found to migrate from Tritan™ containers during all three migration tests (levels around 0.040 µg/kg). Migration of two non-intentionally added substances (NIAS), 4-nonylphenol and 2-phenoxyethanol, was also observed from 19L carboys, albeit only in the first migration test. The monomer dimethyl isophthalate (DMIP, CAS 1459-93-4) was found to migrate from one carboy sample during all three migration tests (level third test 0.085 µg/kg).
As such, BPA, DMIP and BBP from Tritan™ were below the legally binding specific migration limits which apply to the third migration test. The use of BPA in plastic food contact materials in Europe is restricted for use as monomer with a specific migration limit (SML) of 600 µg/kg; for the monomer DMIP the SML is 50 µg/kg. The plastic material Tritan™ is made from dimethyl terephthalate (CAS 120-61-6), 1,4-cyclohexanedimethanol (CAS 105-08-8) and 2,2,4,4-tetramethyl-84 1,3-cyclobutanediol (CAS 3010-96-6) (Osimitz et al. 2012), therefore the presence of DMIP and BPA in Tritan™ is unexpected. BBP is permitted for use as additive in repeated use articles, with an SML of 30 mg/kg.
The authors further tested endocrine disrupting activity of the overall migrates in different yeast assays. None of the overall migrate samples were active under the observed test conditions. However, the detection limit for estrogenicity using the Yeast Estrogen Screen (YES) is considerably higher than in another in vitro assay which previously reported estrogenic activity of plastic migrants (Yang et al. 2011). The estrogenicity of DMIP was also investigated in vivo in a snail bioassay. DMIP was not found to be estrogenic at the tested concentrations of 30 and 100 µg/L while BPA was clearly estrogenic at 30 µg/kg.
References
Guart, A., et al. “Migration of plasticizers from TritanTM and polycarbonate bottles and toxicological evaluation.” Food Chemistry (published online March 13, 2013)
Osimitz, T. G., et al. (2012). “Lack of androgenicity and estrogenicity of the three monomers used in Eastman’s Tritan™ copolyesters.” Food and Chemical Toxicology 50(6): 2196-2205.
Yang, C. Z., et al. (2011). “Most Plastic Products Release Estrogenic Chemicals: A Potential Health Problem That Can Be Solved.” Environmental Health Perspectives 119(7): 989-996.
Read more
EA in Plastics Part I: Is estrogenic activity (EA) in plastics the next BPA? PlasticsToday.com, 10 December 2012
EA in Plastics Part II: Eastman Chemical Co. vs. PlastiPure. PlasticsToday.com, 11 December 2012
EA in Plastics Part III: Science is still developing. PlasticsToday.com, 12 December 2012
