It can be frustrating to train yourself to hydrate your body by consuming at least 64 ounces of water a day, only to learn later that the water you’ve been drinking poses a health risk. Consumers who drink water (or ingest any food) contained in certain hard and soft plastic bottles can expose themselves to health risks associated with chemicals in the plastic. The culprit? Phthalates.
Phthalates are chemical compounds used in the manufacture of various plastics. They are also found in nail polish, adhesives, paint pigments, caulk, even some “adult” toys. Perhaps the highest area for human concern is how phthalates affect the foods we ingest.
#1 soft plastic bottles contain polyethylene terephthalate (PET or PETE for short). Chemical breakdown over time causes a leaching of this chemical into the contained liquid. Many people re-use these bottles, presumably to save the environment or their wallets, introducing the threat of DEHA and benzyl butyl phthalate (BBP). DEHA is a known carcinogen and BBP is a potential hormone disruptor. PET also contains antimony trioxide, a catalyst used in the manufacturing process.
Antimony trioxide is a suspected cancer-causing agent which the European Union considers a priority pollutant. Water contained in PET bottles revealed up to 375 ppt antimony compared with only 8.2 ppt antimony in polypropylene bottles. Three months later, the water in PET bottles contained up to 626 ppt.1 While these levels may be lower than recommended maximum concentrations for drinking water, it has been proven that the levels do increase with age; continuous leaching occurs. The older the plastic, the higher the risks may be. Consumers may be wise to check the bottle’s expiration date before drinking the water contained within.
Bisphenol A (BPA for short) is a plastic additive that hardens plastic and makes it transparent. It is found in #7 plastic, with which Nalgene bottles are made. BPA is also found in many plastic baby bottles and sippy cups. When the chemical bond between BPA and the plastic polycarbonate breaks down, it is leached into the liquid contained in that plastic. This phenomenon is accelerated by heating the plastic. People don’t generally heat bottled water in the bottle, but other plastic containers such as baby bottles and microwave cookware are commonly heated and re-heated. The warmth from heated liquids themselves, even the dishwater used to wash these plastics, stimulates this breakdown and leaching whether or not the container itself was heated.
BPA research in lab animals identifies it as a cause for certain health problems, including obesity, early puberty in females, reduced reproductivity in males, and certain behavioral disorders such as hyperactivity. Researchers widely agree that the effects on humans are at this point non-conclusive because much more research on humans is needed. They also tend to agree that the existing research is a cause for concern for human health.
Antimony trioxide is present in other food packaging. Risks may vary by the type of food with which the chemical is interacting. Of particular interest is the reaction this chemical has with citric acid, which tends to preserve the oxidation state of the antimony. This suggests that juices packaged in plastic bottles may present a higher risk than waters packaged this way. Antimony trioxide is also present in the liners of cans. This extends the risk beyond fruit juices to include canned food items, in particular tomato-based foods, which contain citric acids.
There is evidence that the cumulative effects of exposure to antimony trioxide may lead to chronic toxicity. While the exposure level from one bottle of water or juice may not be a serious threat, over time human health may be compromised.
Numerous research studies commissioned by the plastics industry claim that these health risks do not pose a threat to human health. Also, the Juvenile Products Manufacturer’s Association asserts that plastic bottles are safe. Some scientists maintain that the human body neutralizes and excretes BPA faster than a lab rat’s body. The levels that leach into food are indeed below the safety thresholds set by the EPA. The FDA still maintains that BPA uses with food are safe.
Due to conflicting scientific opinions, more human research is necessary to truly ascertain the health implications that plastic may present. Consumers are advised to review the currently available studies and determine their own conclusions and take any precautionary actions they deem necessary in the meantime.
1Sanderson, Katharine, “Chemical Science”, Journal of Environmental Monitoring, January, 2006.