Health & Wellbeing

Soft plastic bottles leach hundreds of chemicals into drinking water

Soft plastic bottles leach hundreds of chemicals into drinking water
Scientists have found hundreds of chemicals can leach into drinking water from soft plastic bottles
Scientists have found hundreds of chemicals can leach into drinking water from soft plastic bottles
View 1 Image
Scientists have found hundreds of chemicals can leach into drinking water from soft plastic bottles
Scientists have found hundreds of chemicals can leach into drinking water from soft plastic bottles

Recent research has raised the alarm over the potential health impacts of consuming water from plastic bottles, with scientists concerned over the chemicals that can leach into the liquid with unknown impacts on human health. A new study has investigated this phenomenon with regard to bottles of the reusable variety, revealing that they release hundreds of chemicals into the water and why putting them through the dishwasher may be a bad idea.

The study was carried out by researchers at the University of Copenhagen and focused on the type of soft and squeezy bottles used in sports. While these are incredibly commonplace around the world, the authors say there is a big gap in our knowledge around how chemicals from these plastics can migrate into the drinking water they hold, so they conducted experiments to fill in some of the blanks.

Both new and heavily used drink bottles were filled with ordinary tap water and left to rest for 24 hours, both before and after being put through a dishwasher cycle. The scientists used mass spectrometry and a liquid chromatograph to analyze substances in the liquid before and after the machine washing, and also after being rinsed five times with tap water.

"What is released most after machine washing are the soap substances from the surface," said first author Selina Tisler. "Most of the chemicals that come from the water bottle itself remain after machine washing and extra rinsing. The most toxic substances that we identified actually came after the bottle had been in the dishwasher – presumably because washing wears down the plastic and thereby increases leaching."

The scientists found more than 400 different substances in the water that came from the plastic material, and more than 3,500 substances from dishwasher soap. Most of these are unknown substances that the researchers are yet to identify, and even of those that were able to be identified, the toxicity of at least 70 percent of them is unknown.

"We were taken aback by the large amount of chemical substances we found in water after 24 hours in the bottles," said study author Jan H. Christensen. "There were hundreds of substances in the water – including substances never before found in plastic, as well as substances that are potentially harmful to health. After a dishwasher cycle, there were several thousand."

Among the substances that the scientists did find through their experiments were photo-initiators, molecules known to have toxic effects on organisms, with the potential to act as carcinogens and endocrine disruptors. They also discovered plastic softeners, antioxidants and release agents used in plastic manufacturing, along with Diethyltoluamide (DEET), the most common active substance in mosquito repellent.

The scientists believe that only a small number of the detected substances were added to the bottles intentionally during manufacturing. Most of them likely formed during use or production, where one substance may have been converted into another, such as a plastic softener they suspect is converted to DEET as it degrades.

"But even of the known substances that manufacturers deliberately add, only a tiny fraction of the toxicity has been studied," said Tisler. "So, as a consumer, you don't know if any of the others have a detrimental effect on your health."

The study adds to a growing body of research around how humans are likely consuming vast amounts of chemicals through our interactions with plastic products, and further illustrates the many unknowns in this space.

"We care so much about low levels of pesticides in our drinking water," said Christensen. "But when we pour water into a container to drink from, we unflinchingly add hundreds or thousands of substances to the water ourselves. Although we cannot yet say whether the substances in the reusable bottles affect our health, I’ll be using a glass or quality stainless steel bottle in the future."

The research was published in the Journal of Hazardous Materials

Source: University of Copenhagen

Brian M
Big problem with this study is they didn't use any comparison or control - For example why didn't they include, glass, metal and earthenware containers?

Without that control the results aren't of great value, made worse by the comment 'I’ll be using a glass or quality stainless steel bottle in the future."
Might well be right but you haven't proved it with good science!
i take it that milk, soda, water, yogurt, cottage cheese, etc. all are affected by this.
Not stated - did they neglect to test the Copenhagen water prior to filling the bottles? Might want to filter your tap water, Copenhagen!
"with unknown impacts on human health" means, well, no one knows. Get back to us when you do. Meanwhile we'll take comfort in knowing that we breathe and ingest thousands of chemicals every day with apparently little effect except the obviously noxious ones. Our bodies are remarkable at managing minute quantities of sometimes deadly chemicals and toxins like botulinum. Just because you can measure chemicals in ever smaller quantities in parts per billion doesn't mean such small amounts have any detrimental effects.
Nothing quantifies the potential danger of these "chemicals". I'm particularly concerned about Dihydrogen Oxide, Hydrogen Hydroxide, Hydronium Hydroxide, and Hydric acid.
aksdad beat me to it. This reads like a kid with a new toy (super-duper sensitive chemical detector): "Look at all the chemicals I've detected!" It doesn't say how much is present or how much risk it presents at that level or compare it to what we typically consume during a day, even with glass containers. It's a flashy newsbite, not an important scientific discovery.
Douglas Rogers
They didn't say what plastic the bottle was made of. I suspect is wasn't polyethylene.
@Douglas Rogers, read the linked study. It does specify that they're polyethylene.
@Brian M - read the study, it's linked beneath the article. A Duran glass bottle was the control, and the bottle was heated to 550 degC prior to use to remove contaminants.

@BlueOak - read the study. Water from the glass bottle was tested, so that would provide the reference for Copenhagen tap water.

So little sense of inquiry among the commenters here.
This confirms what I've read elsewhere. I usually avoid buying liquids in plastic containers if possible. Glass is good, not just for me but for the environment when discarded.
Load More