Tuesday, January 29, 2008

Reduce your use of toxic chemicals – Part I: Plastics

Who hasn't suspected that plastics aren't entirely safe? Anyone with taste buds can tell that plastics leach into the foods and drinks we store in them. After all, nearly all plastics are petroleum byproducts.

Plastics are everywhere. There are seven types of plastics that are commonly identified for recycling purposes with a "resin identification code". These codes reveal the class of plastic and can help you avoid plastics that contain, leach, or outgas toxins.

"Good" plastics with no components or leachates that are yet known to be hazardous to human health:

#1 PETE or PET - polyethylene terephthalate
#2 HDPE - high density polyethylene
#4 LDPE - low density polyethylene
#5 PP - polypropylene

Dangerous plastics:

#3 PVC or V - polyvinyl chloride: Manufacturing or burning PVC releases carcinogens (dioxins). Phthalates are "plasticizers" that make PVC more pliable. Vinyl shower curtains are loaded with phthalates. Examples of PVC: plastic "cling" wrap, anything with the "new car" or "new shower curtain" smell, PVC piping/plumbing. Science News articles suggest these effects of phthalates: may reduce sperm count or damage sperm in males, may shorten pregnancy, worsens skin allergies, may boost obesity, may cause developmental damage to fetuses, may elevate risk for developing asthma, eczema, and rhinitis, can mimic estrogen and "feminize" boys

#6 PS - polystyrene (aka "Styrofoam"): Made from styrene, a suspected carcinogen, PS also contains p-nonylphenol; both chemicals are suspected endocrine disruptors. Don't consume fatty foods or alcoholic beverages from Styrofoam containers; styrene can leach into these substances (I've actually watched styrofoam dissolve in beer.). Some opaque plastic cutlery is PS, as well.

#7 "Other" - includes a range of plastics like PC (polycarbonate), acrylic, fiberglass, and nylon: The major toxic concern is bisphenol-A (bpA) used in polycarbonate plastic. BpA is the chemical that links the plastic polymers together. Articles in Science News suggest that bpA has these effects: carcinogen, exposure in utero can disrupt brain and reproductive development, mimics the hormone estrogen, can "feminize" males, may cause illness, may cause genetic mutations, may increase risk of developing diabetes. Science News articles suggest that nearly all polycarbonate plastics will leach bpA when heated. Older PC bottles (cracked or cloudy) will leach 2 to 5 times more bpA than newer PC bottles unless the newer bottles have been scratched. New PC bottles that are scratched leach several times as much bpA as older, unscratched bottles. BpA can also leach into liquids from canned foods that use a PC can lining. For some reason, coffee in PC lined cans leaches 10 times as much bpA as any other tested liquid.

Bad news, backpackers. Those Nalgene bottles you've been using for years are made of Lexan, which is polycarbonate and contains bisphenol-A (Nalgene address bpA in their PC bottles). If you can still read the number, check the bottom of your Nalgene bottles: all #7s.

Even worse, the longer you've been using them, the more likely they are to be leaching bpA into your water. If you're like me, you've got opaque bottles dating back to Boy Scouts that used to be translucent still in circulation. Worst of all, bpA leaches from polycarbonate 10 times more when exposed to hot coffee. Backcountry Starbucks anyone? Heck, I used to pour coffee straight from coffee pot to Nalgene for my morning commute. Other brands that use polycarbonate: CamelBak, GSI, anything that says Lexan

Alternatives (all available at REI):

HDPE from Nalgene
Stainless steel: Kleen Kanteen
Aluminum: SIGG

More resources

Which plastics are safe or unsafe for food use? In what items are these plastics found (baby bottles, etc.)? Check out the Institute for Agriculture and Trade Policy's Smart Plastics Guide Healthier Food Uses of Plastics for Parents and Children (a quick pdf download) .

Bisphenol A FREE - A website digest of news stories about bpA.

Be Safe - National organization that lobbies large corporations to reduce prevalance of chemicals like PVC, dioxin, etc.

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