Diethylhexyl phthalate as a current problem of hygienic safety of packaging and packaged drinking water

Introduction. The chemical safety of packaged drinking water is influenced by many factors, including the quality of packaging materials. The chemical components included in the packaging can migrate into drinking water and have a negative impact on human health. The most common types of packaging for drinking water are polyethylene terephthalate (PET, PET) and polycarbonate (PC) bottles. In the production of polymers, to soften and increase the flexibility of the finished product, special substances are added to the material — plasticisers, including dialkyl or alkyl aryl esters of orthophthalic acid (phthalates), among which di (2-Ethylhexyl) phthalate (DEHP), which has toxic properties.

The purpose of this study is to analyse various samples of plastic containers in contact with drinking water for the presence of DEHP in polymers and to study the emission of DEHP from polymer packaging into a model environment.

Materials and methods. Research has been carried out on 11 samples of containers for drinking water of domestic production, of which nine samples were represented by PET bottles of various sizes and two samples of containers from PC with a volume of 19.0 litres. There was determined the content of DEHP in the container material and the level of migration of DEHP into the aqueous model environment. Sanitary and hygienic studies were carried out based on the Сhemical Analytical Center “Arbitrage” of the DI. Mendeleev All-Russian Scientific Research Institute using gas chromatography with mass spectrometric detection (GC-MS). GSO 11366-2019 for the composition of a solution of orthophthalic acid esters in methanol was used as a standard sample for the calibration characteristics; a deuterated analogue of the analyte, DEHP-D4, was chosen as an internal standard.

Results. In all studied samples of packaging materials, the residual content of DEHP was in the range of 1.7–4.2 mg/kg of polymer; the levels of DEHP migration into aquatic model media were determined at T = 20 °C and T = 40 °C in the range of (8.6–71.0) μg/dm³.

Conclusion. One of the sources of contamination of packaged drinking water with DEHP is PET and PC containers. The results obtained indicate the need to include DEHP in the list of monitored sanitary and hygienic safety indicators in the technical regulations of the EAEU TR 044/2017 and TR CU 005/2011 and to consider the issue of restrictions on its use in the production of food packaging.

Limitations of the study. As part of this work, samples of bottles from six domestic container manufacturers were analysed. To study the migration of the target component, a model medium was used — distilled water, which does not imitate the mineral composition of drinking water and has certain pH and electrical conductivity values. Studies of the level of DEHP migration were carried out at an ambient temperature of 20 °C and 40 °C and an exposure time of 30 days. The measurement range of DEHP in polymers and the model medium in this study was (0.1–5) µg/sample. The expanded uncertainty of the results of measurements of the DEHP content in the entire measurement range did not exceed 20%.

Contribution:

Zaritskaya E.V. — concept and design of the study, analysis of measurement results, writing the text;

Mikheeva A.Yu. — choice of analytical methods, writing the text;

Ganichev P.A. — literature review, collection and processing of experimental materials;

Markova O.L. — processing of experimental materials, statistical processing, writing the text;

Yeremin G.B. — editing.

All co-authors — approval of the final version of the article, responsibility for the integrity of all parts of the article.

Conflict of interest. The authors declare no conflict of interest.

Acknowledgement. The study had no sponsorship.

Received: August 4, 2021 / Accepted: November 25, 2021 / Published: February 09, 2022