Plastic Bottle Education

Plastic bottles were uncommon until the late 1940’s. They remained expensive until the invention of high density polyethylene in the 1960’s. Popularity then zoomed among both the manufacturers and consumers because plastics were light in weight and cheaper to make.

The controversy about plastic safety is eternal, not only because of health issues, but also because of environmental concerns. Here’s what we need to know. Note that it’s not a good idea to refill any plastic bottle, especially with chlorine-laden tap water.

	PET—polyethylene terephthalate—is really a misnomer because it does not contain polyethylene. It really doesn’t contain phthalates, either. It’s used in soft drink, water, and salad dressing bottles, and in peanut butter, pickle, and jelly jars. Only about 30% of the planet’s PET is used for bottles; most is used to make synthetic fibers. The antimony used as a catalytic agent in PET’s manufacture can leach into the contents if exposed to extremely high heat or to the microwave. Rating: GOOD—not known to leach chemicals suspected of carcinogenesis or hormone disruption.
	HDPE—high density polyethylene—is used in milk, water, and juice bottles, in yogurt and margarine containers, and in grocery and trash bags; occasionally in toiletries and water pipes. Rating: GOOD—not known to leach harmful chemicals into the contents.
	PVC—polyvinyl chloride—is found in plastic cling films (from the deli, for example), occasionally in juice bottles, in water and sewer pipes, and if unplasticized, in vinyl siding. Traces of the plasticizers, most often phthalates, leach into the foods. Rating: BAD—plasticizers (phthalates) can disrupt normal hormone function and possibly cause cancer.
	LDPE—low-density polyethylene—is used to make frozen food bags (the low-density is bendable), squeeze bottles for honey and mustard, cling films, and flexible lids. Rating: O. K.—it doesn’t leach anything, but is difficult to recycle.
	PP—polypropylene—may be found in reusable microwave containers, in kitchenware, yogurt and margarine tubs, some ketchup bottles, and Legos. Because it’s resistant to fatigue, it’s used to make hinges on flip-top lids. Rating: O. K.—its manufacture is somewhat hazardous, but it doesn’t leach any cancer-causing or hormone-disrupting chemicals.
	PS—polystyrene—is commonly found in egg cartons, packing peanuts, disposable cups, plates and trays, and some cutlery. It’s one of the most widely used plastics. Foam insulation is made from PS. Rating: BAD—because it is made from suspected carcinogenic substances and may be neurotoxic, despite its approval for food use. Never put any acidic beverage into a Styrofoam cup. Wine may dissolve it, and fats may absorb it. That means using no cream in coffee.
	Other—means polycarbonate, ABS, or BPA, none of which should be used for food contact. It has been used to make baby bottles, water bottles, eating utensils, and linings for metal cans. It may also appear inside juice boxes. It was invented in the 1930’s in the search for synthetic estrogens. It is a hormone disrupter that simulates the physiological activity of estrogen. It will leach into the contents. Rating: BAD—because it also affects neurological function, weight management, infant development and behavior, dopaminergic systems, thyroid hormone receptors, prostate function, and DNA methylation.

That PET has the term terephthalate is misleading. Terephthalate is not the same thing as phthalate. The former comes from terephthalic acid, chemical formula C₆H₄(COOH)₂. The latter comes from phthalic acid, formula C₆H₄(CO2H)₂. The chemical difference is easily seen.

The American Chemistry Council asserts that phthalates are not used to make beverage bottles or any other type of plastic food-contact product. Phthalates, or rather orthophthalates, are used to make PVC flexible, as found in shower curtains and vinyl flooring. (Enneking, 2006)

A concern about PET is the leaching of antimony, a catalyst in PET manufacture, into the contents of the bottle. Any residue can be removed by washing. Some remains in the material, being released if heated.

Andra SS, Makris KC, Shine JP, Lu C. Co-leaching of brominated compounds and antimony from bottled water. Environ Int. 2012 Jan;38(1):45-53.

Bach C, Dauchy X, Chagnon MC, Etienne S. Chemical compounds and toxicological assessments of drinking water stored in polyethylene terephthalate (PET) bottles: A source of controversy reviewed. Water Res. 2012 Mar 1;46(3):571-83.

David Biello Plastic (Not) Fantastic: Food Containers Leach a Potentially Harmful Chemical Is bisphenol A, a major ingredient in many plastics, healthy for children and other living things? Scientific American; February 19, 2008 http://www.scientificamerican.com/article.cfm?id=plastic-not-fantastic-with-bisphenol-a

Eilam-Stock T, Serrano P, Frankfurt M, Luine V. Bisphenol-A impairs memory and reduces dendritic spine density in adult male rats. Behav Neurosci. 2011 Oct 17.

Patricia A. Enneking Phthalates Not in Plastic Food Packaging Environ Health Perspect. 2006 February; 114(2): A89–A90.

Hansen C, Tsirigotaki A, Bak SA, Pergantis SA, Stürup S, Gammelgaard B, Hansen HR. Elevated antimony concentrations in commercial juices. J Environ Monit. 2010 Apr;12(4):822-4.

Kate Kelland Scientists link plastics chemical to health risks Exposure to a chemical found in plastic containers is linked to heart disease, scientists said on Wednesday, confirming earlier findings and adding to pressure to ban its use in bottles and food packaging. (Reuters) - Wed Jan 13, 2010 http://www.reuters.com/article/2010/01/13/us-heart-chemical-plastics-s-idUSTRE60C0AR20100113

Kolšek K, Mavri J, Sollner Dolenc M. Reactivity of bisphenol A-3,4-quinone with DNA. A quantum chemical study. Toxicol In Vitro. 2012 Feb;26(1):102-6. Epub 2011 Nov 20.

SAKAMOTO HIROMI, MATSUZAKA AYAKO, ITO RIMIKO, TOYAMA YUKO Quantitative Analysis of Styrene Dimer and Trimers Migrated from Disposable Lunch Boxes. Journal of the Food Hygienic Society of Japan. VOL.41;NO.3;PAGE.200-205(2000)

Schmid P, Kohler M, Meierhofer R, Luzi S, Wegelin M. Does the reuse of PET bottles during solar water disinfection pose a health risk due to the migration of plasticisers and other chemicals into the water? Water Res. 2008 Dec;42(20):5054-60.

Shotyk W, Krachler M, Chen B. Contamination of Canadian and European bottled waters with antimony from PET containers. J Environ Monit. 2006 Feb;8(2):288-92.

Vasami R Polyethylene Terephthalate and Endocrine Disruptors. Environ Health Perspect. 2010; 118:A196-A197.