There are many claims online about the health risks of drinking out of plastic bottles. But what is the truth? Read on to have light shone on this common misconception.

Doug from Perth asked:

Does drinking water from plastic bottles that have been left in a warm car increase your risk of getting cancer?"

It’s safe to drink water out of plastic bottles without a risk of cancer even when the bottle has been left in hot cars, frozen or reused. There is no scientific evidence to dispute this.

Drinking water out of plastic bottles is safe, although, for many years, people have been circulating hoax emails incorrectly claiming differently. Many of these emails credit the false information to Johns Hopkins University or the Walter Reed Army Medical Center, but both institutions have denied any involvement.

Heating, freezing and reusing water bottles is also safe, hoax emails claim that this can release damaging chemicals but there is no scientific evidence to prove this. BPA has also been falsely posed as a concern, however, Food Standards Australia New Zealand states that BPA is safe. Materials used in water bottles and other food containers, such as BPA, are safe.

All in all, water in plastic bottles is safe to drink. The same goes for water in metal bottles or any other type of drink container. However, bacteria and fungi can grow in bottled water, so if they have been left for a long time, it is best to clean them out with hot, soapy water and leave them to dry before refilling them.

Top tip: Only refer to credible scientific resources for your cancer information and avoid things found on social media or non-accredited websites.

Our iHeard articles are evidence-based and we use an array of language to bring meaning to each topic. For example, in this article we use the word 'safe', this is not seen as a scientific word and therefore warrants some explanation. Discover what we mean by the word 'safe'.

iHeard hub

Thank you for joining the mission against misinformation

If you’ve heard a rumour about cancer, or are unsure about information you’ve read online, ask your own cancer question via the iHeard hub.  

We want everyone to have the correct information about cancer so if you know anyone else with a cancer question, why not let them know about iHeard?  

This article was last updated 20/10/2023.