|
 
|
THE GREAT WATER BOTTLE DEBATE
An interesting read from the office Fit City newsletter.
THE GREAT WATER BOTTLE DEBATE
Some of the most popular reusable water bottles have been made from a hard clear plastic called polycarbonate. The concern is that one of the key components of polycarbonate is the endocrine-disrupting chemical bisphenol-A (BPA). A growing body of research has shown that polycarbonate bottles can leach BPA into the liquid they contain. BPA mimics the female hormone estrogen and has been shown to cause defective cell division during development, even at extremely low doses.
Are they safe to use? The demand from consumer health and environmental groups prompted the federal government to fast-track a screening assessment of BPA in 2007. During this time, some major retailers including Mountain Equipment Co-op, removed these products from their shelves. The assessment was released April 18th, 2008 and stated that there is no conclusive evidence to show that the level of BPA leached from plastic water bottles is dangerous to adults. Studies regarding this issue have all found that the amount of BPA leached from these bottles is too minimal to be labelled a health threat. The biggest risk seems to be for foetuses, pregnant women, infants and children, who are more sensitive to the effects of BPA. Low doses of BPA cause structural changes in the developing brain that trigger learning deficits and hyperactivity. There is also some concern that it harms the prostate gland and causes premature puberty. A ban will be imposed on the importation, sale and advertising of polycarbonate baby bottles and with this action, Canada will be the first country in the world to take such action to limit exposure to BPA.
Taking care: Avoid freezing or adding boiling water to your water bottle. Clean it daily by hand (not in the dishwasher) and stop using it if it shows cracks or wear and tear. All of these actions will limit the amount of BPA leached.
What to buy? If you want a plastic bottle, the safest bottles to use are: high density polyethylene, or HDPE (identified by the number 2 in the recycling triangle symbol on the bottom), low density polyethylene, or LDPE (#4) or polypropylene (#5). The #7 miscellaneous category that includes polycarbonate (PC) used for most clear plastic bottles (including the Fit City incentive prize bottles) can leach BPA - especially if heated though, as stated above, pose no real harm to adults.
The best choice for reusable water bottles is one made from stainless steel. They can handle most liquids, can be cleaned easily and most importantly, don’t leach chemicals. However, watch out for those stainless steel bottles that have an epoxy resin lining, which can also leach chemicals, including BPA. There is also new BPA-free plastic called ‘Tritan Copolyester’ expected to be on the market this year, which like polycarbonate, will carry the same #7 in the recycling triangle on the bottom of the bottle. This will likely make it trickier for
consumers to navigate, though manufacturers will undoubtedly market the new bottles as BPA –free.
Much of the information in this article, as well as answers to more specific questions about products containing BPA, can be found on
the Health Canada website at http://www.chemicalsubstanceschi ... _a_qa-qr_e.html#11. |
|
發表於 2008-6-30 10:34
| 
