Reuse of PET-Water Containers
FACS has received a large number of queries regarding the safety of washing and reusing PET mineral water bottles. These result from e-mails circulating on the internet claiming that washing of PET bottles results in the formation of carcinogenic compounds. Specific mention is made to the formation of the chemical, DEHA.
Reusing any food or drinks container without adequate washing with warm, soapy water, and rinsing, can result in the spread of germs. However, you can be assured that it is quite safe to reuse PET bottles without any risk of degradation or contamination, providing that normal good hygiene practices are observed.
The plastic material, PET (polyethylene terephthalate), used for mineral water and other beverage bottles, has been thoroughly tested and approved as safe for food contact use by international health authorities. Although most water and beverage bottles are lightweight and designed for single use, refillable, reusable PET bottles are also quite widely used, with appropriate hygienic washing procedures. This also has full approval of the health authorities.
The Internet scare story originated from the University of Idaho. A student doing an investigation into the reuse of PET bottles detected traces of DEHA in bottles "exposed to realistic but extreme reuse parameters." The suggestion was made that this could result in an increased risk of carcinogenicity. Unfortunately this was picked up by the media, and reported on without verification. The original study correctly identifies DEHA as diethylhexyl adipate. The versions circulating on the Internet incorrectly refer to it as diethylhydroxyamine.
The fact is that DEHA is not inherent in PET as a raw material or as a decomposition product of PET. DEHA is approved for food contact applications and would not pose a health risk even if it were present. It is commonly used as a plasticiser in many other plastic items, used on a daily basis. It is presumed that the DEHA detected in PET bottles by the student at Idaho University probably originated from other plastic components in the laboratory environment.
A study conducted by the Swiss Federal Laboratories for Materials Testing and Research (EMPA) on the reuse of PET bottles also detected trace amounts of DEHA in PET bottles, but this was in the same range as detected in pure water in glass laboratory flasks. Furthermore, these levels are distinctly below the WHO guidelines for drinking water quality (80 µg/L for DEHA).
For further reference see the following:
White Paper on Refillable Plastic Packaging Made from PET (Polyethylene Terephthalate). International Life Sciences Institute (ILSI) - North America, 1994. page 58
International Life Sciences Institute. Packaging Materials 1. Polyethylene Terephthalate (PET) for Food Packaging Applications. July 2000. http://www.ilsi.org/file/ILSIPET.pdf
Reviewed for FACS by HBo (2016)