What Plastics Are Safe for Water Bottles?

Bottled water scares have become more common over the past several years, and the facts behind many of these sentiments bear out public concern: bottled water is often laced with harmful chemicals, and there is still virtually zero oversight of bottled water for chemical contaminants. Making matters worse, the reuse of certain kinds of plastic water bottles can render them more harmful.

Potential Chemical Contaminants

• Copolyester, polycarbonate, bisphenol A (BPA), phthalates, Bis(2-ethylhexyl) adipate (DEHA) ... the chemicals found in bottled water are a poorly regulated alphabet soup of carcinogens.

Most Common Concerns

• Plastics No. 1 (PET or PETE) and Nos. 3 & 6 (styrenes) should, if purchased, never be reused. This includes most water sold in disposable bottles.

Nalgene and BPA

• Polycarbonate bottles, such as those sold under the Nalgene brand, have been shown to contain a level of BPA that the U.S. government has dubbed "generally safe." However, Canada became the first country to declare BPA a toxic substance in September 2010.

Heating & Freezing

• Plastic containers of any type should never be heated, although (contrary to some reports) freezing them will not cause chemicals to leach more rapidly into the water.

The Best Choice?

• The safest route is a reusable aluminum or stainless steel water bottle. This is also the cheapest route: the Natural Resources Defense Council has determined that bottled water is up to 10,000 times more expensive than tap water and with far less stringent safety controls.