As a general rule, you can identify plastics by the recycling code number stamped on the bottom of an item.
Safest Plastics for You and the Environment
*Polyethylene terephthalate (PET or PETE) (#1) containers are recyclable and generally considered the safest single-use plastic-bottle choice. But they are best not reused because studies indicate that after repeated use, PET containers may leach DEHP, an endocrine-disrupting phthalate and probable human carcinogen.
*High-density polyethylene (HDPE) (#2) is both durable and accepted by most curbside recycling programs. Alas, few reusable #2 containers are available.
*Low-density polyethylene (LDPE) (#4), like its cousin HDPE, is a food-safe plastic, mostly used to make food wraps and plastic bags.
*Polypropylene (PP) (#5), though less recyclable, has not been shown to leach any carcinogens or endocrine disruptors. Readily available in reusable containers.
Plastics to Use with Caution
*Polycarbonate (#7) plastics, used in the popular Nalgene Lexan sports bottles and some baby bottles, contain bisphenol-A, a known hormone disruptor that may leach in some circumstances. More research is needed before any potential health risk is known. In the meantime, do not expose bottles to heat or use when visibly worn.
Plastics to Avoid
#3 Polyvinyl Chloride (PVC) commonly contains di-2-ehtylhexyl phthalate (DEHP), an endocrine disruptor and probable human carcinogen, as a softener.
#6 Polystyrene (PS) may leach styrene, a possible endocrine disruptor and human carcinogen, into water and food.
#7 Polycarbonate contains the hormone disruptor bisphenol-A, which can leach out as bottles age, are heated or exposed to acidic solutions. Unfortunately, #7 is used in most baby bottles and five-gallon water jugs and in many reusable sports bottles.
#1 polyethylene terephthalate (PET or PETE), the most common and easily recycled plastic for bottled water and soft drinks, has also been considered the most safe. However, one 2003 Italian study found that the amount of DEHP in bottled spring water increased after 9 months of storage in a PET bottle.
#2 High Density Polyethylene
#4 Low Density Polyethylene
Best Reusable Bottles: Betras USA Sports Bottles, Brita Fill & Go Water Filtration Bottle, Arrow Canteen
Better Baby Bottles: Choose tempered glass or opaque plastic made of polypropylene (#5) or polyethylene (#1), which do not contain bisphenol-A.
Tips for Use:
*Sniff and Taste: If there's a hint of plastic in your water, don't drink it.
*Keep bottled water away from heat, which promotes leaching of chemicals.
*Use bottled water quickly, as chemicals may migrate from plastic during storage. Ask retailers how long water has been on their shelves, and don't buy if it's been months.
*Do not reuse bottles intended for single use. Reused water bottles also make good breeding grounds for bacteria.
*Choose rigid, reusable containers or, for hot/acidic liquids, thermoses with stainless steel or ceramic interiors.