Today on the way down in the lift I noticed a woman drinking from a used commercial water bottle. I wondered if she knew that there are some serious dangers with reusing plastic water bottles. Whilst there has been a huge amount of debate over this very topic the truth is that all plastics emit small amounts of plasticizer over time. And whilst the US FDA has advised that these plasticizers are harmless in small doses, and don’t pose a risk to consumers, other scientists beg to differ.

The issue is predominately with #3 or #7 plastics, or any hard plastic that are “shatterproof.” These plastics contain a chemical called Bisphenol A (BPA), which once ingested, mimics estrogen in our bodies. According to Scientific American, studies have shown that a build up of these chemicals can promote human breast cancer cell growth and lower sperm counts. Pregnant women, infants and children are especially at risk. But it’s important to remember that all plastic water bottled and containers leach small amounts of plasticizers over time, even if they are BPA-free.

And the issue becomes more complex if your main source of water is from plastic bottles, or if those bottles are ever frozen or heated (for example if left in a car on a warm day). Add to this the even more imminent danger that reused water bottles can contain dangerous build ups of bacteria if not washed thoroughly with soap and hot water between uses. If you refill a bottle without washing it you run the risk of bacteria left from the drinker’s mouth multiplying and building colonies on the bottle’s walls and grooves. And if your drink is anything but 100% water then the bacterial issue becomes worse as bacteria will use the addatives (such as sugar) as a food source to fuel their multiplication.

So, what’s the answer? The best option is to filter your fresh water straight from the tap as you need it (remember even tap water contains some bacteria). However if bottled water is required then the best options are glass containers (e.g. thermos with a glass insert) then special water carriers that are BPA-free which can be easily cleaned. Tupperware has some great relatively cheap options availble if you have a home water filter, and if you don’t then the Bobble could be exactly what you need!