73D-18 |
Effect of ozone treatment of drinking water on plastic packaging materials |
Y. S. SONG1, F. Al-Taher2, L. Xu3, and G. Sadler2. (1) National Center for Food Safety & Technology, U.S. Food & Drug Administration, IIT Moffett Campus, 6502 S. Archer Rd., Summit-Argo, IL 60501, (2) National Center for Food Safety & Technology, Illinois Institute of Technology, IIT Moffett Campus, 6502 S. Archer Rd., Summit-Argo, IL 60501, (3) Praxair Inc., 7000 High Grove Blvd., Burr Ridge, IL 60521 Ozonation is commonly used worldwide for disinfection of drinking water to be held in plastic polymer bottles. Some anecdotal evidence suggest that ozonated bottled water gives more off-taste than does non-ozonated bottled water. This may be attributed to residual ozone attack of chemical double bonds, which may degrade the polymers to impart a unique organic background to water. However, scientific information is limited. This research was conducted to measure the migration of residual compounds and degradation products into ozonated water from polyethylene terephthalate (PET) and high density polyethylene (HDPE) bottles, polypropylene (PP) cap and ethylene vinyl acetate (EVA) liner. Deionized and distilled water in a 4-L amber glass container at 5oC was treated with ozone gas to achieve 5ppm ozone level in water. Polymer strips and disks were immersed in ozonated and non-ozonated water inside a jar, which was screw-sealed and stored at 40oC for 10 days. Residual compounds in water were identified and quantified using analytical methods developed and validated using a high-pressure liquid chromatograph with photodiode array detection. No new chemicals were generated by ozonation. No significant peak changes were observed before and after ozonation for HDPE, PP, and EVA polymers. Although HDPE and PP each contained 600ppm Irganox 1010 and BHT respectively, no migration of either antioxidant occurred. For PET, however, the average concentration of monohydroxy ethylene terephthalic acid (MHET) increased three times after ozone treatment. The concentrations of terephthalic acid (TA), MHET and bis(2-hydroxyethyl) terephthalate (BHET) in water indicated that migration occurred in ozonated water at concentrations below the FDA's 0.5ppb dietary concentration limit. These results imply that even at a treatment level more than 10 times the current regulatory limits for bottled water, extractives from packaging materials were within the levels authorized by the food additive regulations for safe use of plastic polymers.
Session 73D, Food Packaging
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