Post by Emily White
You see it all the time; people buy a plastic water bottle from the supermarket and reuse it for weeks on end. After all, it is ridiculous (both environmentally and economically) to buy a plastic water bottle, only to throw them out after one use. But how safe is it to reuse these bottles?
The plastic in water bottles contains plasticisers to keep them soft and flexible. Pure plastic is very brittle and therefore plasticisers such as phthalates are used in order to improve flexibility. Over time, some of these chemicals can leach out of the plastic and into the water within the bottle. This is particularly worsened when heated or when the contents are acidic. Therefore if you either leave your drink bottle in a warm car for an extended period or you increase the acidity of your water, say by adding lemon, you are increasing your exposure to these chemicals. Plasticisers are thought to interfere with the endocrine system, including the oestrogen and thyroid hormone systems (1, 2).
Majority of plastic water bottles contain BPA (Bisphenol A). Conclusions regarding health risks of BPA vary between assessments from “there is no risk to any part of the population” to “there is risk to the entire population”. However due to potential human health risks from long-term exposure to BPA it is strongly recommended to limit your exposure to this chemical (3). BPA is an endocrine disruptor that can alter the functioning of our endocrine system by mimicking the role of the body’s natural hormones. While hormones are fundamentally chemicals that carry messages around our body from our organs to our cells, even small amounts of unwanted man-made hormones have the power to cause big changes in our body.
Another growing issue is the rise of BPA free plastic water bottles. Many people believe that these are a much safer alternative. It has been shown that the chemicals that are used in place of BPA are in fact very similar, with similar health risks. Unfortunately, BPA-free is nothing more then a marketing ploy (4).
In order to minimize your exposure to these chemicals it is suggested that you opt for water bottles that are either glass or stainless steel. These options are both healthier and better for the environment. If you have no choice but to buy a bottle of water made from plastic, don’t reuse it and don’t drink out of it if it has been left in a warm spot. Don’t be fooled by the BPA-free plastic products as often they contain chemicals that are just as bad as BPA itself. There are so many companies now producing reusable glass/ stainless steel water bottles so there just isn’t any excuse to still be reusing plastic bottles!
1. Ghisari M, Bonefeld-Jorgensen EC. Effects of plasticizers and their mixtures on estrogen receptor and thyroid hormone functions. Toxicology Letters. 2009;189(1):67-77.
2. Waring RH, Harris RM. Endocrine disrupters: A human risk? Molecular and Cellular Endocrinology. 2005;244(1–2):2-9.
3. Huang YQ, Wong CKC, Zheng JS, Bouwman H, Barra R, Wahlström B, et al. Bisphenol A (BPA) in China: A review of sources, environmental levels, and potential human health impacts. Environment International. 2012;42:91-9.
4. Rochester JR, Bolden AL. Bisphenol S and F: A Systematic Review and Comparison of the Hormonal Activity of Bisphenol A Substitutes. Environ Health Perspect. 2015;123(7):643-50.