Children's Drinking Bottles Can Release Endocrine-Disrupting Phthalates
Plastic drinking bottles for children can release the endocrine-disrupting phthalate DiBP after multiple cycles in the dishwasher, according to a new European study.
When your child's drinking bottle needs cleaning, the easiest solution may be to put it in the dishwasher. However, soft plastic, from which many children's drinking bottles are made, may not withstand this.
A wash in the dishwasher can wear down the plastic and release unwanted chemicals into the water, juice, or milk you later pour into the bottle.
22 out of 39 drinking bottles bought in five European countries released the endocrine-disrupting phthalate DiBP after being washed 20 times in the dishwasher, according to a new European study that includes The Danish Consumer Council THINK Chemicals.
Phthalates Don't Belong in Drinking Bottles
There are many phthalates, and DiBP is just one of them that can have negative health effects.
Therefore, DiBP is not allowed to be used as a building block or additive in plastics for food. However, the substance can still be present in small amounts in the plastic.
"We may find DiBP as a contaminant from production or because it can still be used as a so-called technical support agent in the manufacturing of some types of plastic," says Stine Müller.
EU regulations allow DiBP to be released in small amounts from food packaging and have set a migration limit.
"In our test, none of the products exceed the allowed migration limit, and none of the tested drinking bottles themselves pose a risk. However, we still insist that problematic phthalates should not be present in the plastic used for our food," she says.
The finding of DiBP does not surprise senior researcher Hanne Frederiksen from the Department of Growth and Reproduction at Rigshospitalet:
"We are not surprised that DiBP is released from drinking bottles and other plastic products. We still find both this and other regulated phthalates in the urine of all the population groups we have examined. Our exposure to these substances has gradually decreased over the years, but we are still exposed to them. We do not know the exact sources tof exposure, but the discovery of DiBP from drinking bottles may be one of the many small sources contributing to the overall exposure to phthalates, which is likely still problematic, especially for children and pregnant women," she explains.
DiBP is one of four phthalates that were banned in consumer products for indoor use throughout the EU in 2020.
Toys, Children's Clothing, and Carpets May Contain Phthalates
DiBP is not only found in plastic drinking bottles. You may encounter it in many other everyday products, especially those your children come into contact with. This can be in toys, children's clothing, and carpets that your child comes in contact with. The substance is not dangerous in the individual product, nor in the drinking bottles in our study. Instead, it is the overall exposure from many different sources that can pose a health risk. This is known as the cocktail effect.
The EU Commission assesses that DiBP can significantly contribute to the cocktail effect of unwanted chemicals, and therefore it is important to be aware of harmful substances, like DiBP, that can reduce our ability to have children.
"Children are generally more vulnerable to substances that disrupt our hormone system. Both because the dose they are exposed to is typically higher due to their smaller body weight and because they are under development, which is largely promoted by hormones," says Stine Müller.
Recommendations for Drinking Bottles
Choose drinking bottles made of stainless steel or glass, which generally release less unwanted chemicals than plastic.
If you use plastic drinking bottles, here are four tips:
- Follow the instructions regarding temperature, dishwasher use, etc.
- Primarily use plastic drinking bottles for water, as other beverages like juice and milk can increase the release of unwanted chemicals.
- Regularly change the water in the drinking bottle.
- Wash the drinking bottle by hand.
About the test
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The Danish Consumer Council THINK Chemicals participated in a European study where a total of 39 drinking bottles were examined for the release of chemicals into the contents of the drinking bottles.
The drinking bottles were purchased in the Netherlands, the Czech Republic, Spain, Latvia, and Denmark in 2023.
Through laboratory tests, we examined the drinking bottles for the release of various substances. We primarily tested the drinking bottles for phthalates and other plasticizers.
We tested the release of 36 substances both from brand-new drinking bottles and from drinking bottles that had been through 20 dishwasher cycles.
From both the new and machine-washed bottles, we measured the release into three percent acetic acid after it had been left for one and ten days in the drinking bottle. In both cases, two drinking bottles of each product were examined. The two machine-washed drinking bottles were washed in separate dishwashers, along with the other drinking bottles. Negative controls were also included in the dishwasher. This means bottles that we know are free of any of the tested substances.
The test included drinking bottles made of polyethylene, polypropylene, polyethylene terephthalate, polystyrene, polycarbonate, and polyester (Tritan).
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In several of the drinking bottles, we found the release of the phthalate DiBP (diisobutylphthalate), mainly after the bottles had been washed in the dishwasher.
In 22 out of the 39 European drinking bottles, DiBP was found to be released after 20 dishwasher cycles.
Only one of the 39 bottles also released DiBP when new. It was not one of the products from the Danish market.
For the Danish drinking bottles, we found the release of DiBP after dishwasher cleaning in half of the tested bottles.
The drinking bottles did not release any other substances investigated.
The results of the test show that dishwashing affects the release of chemicals, probably because dishwashing increases the breakdown of the plastic and thus also the release.
Throughout the study, the drinking bottles that released DiBP after repeated washing were made of PE (polyethylene) or PP (polypropylene).
We did not see the release of phthalates from drinking bottles made of other types of plastic.