Plasticisers in water bottles and what PET bottles really contain

Plasticisers are a group of additives that make hard, brittle materials soft, flexible and stretchy. The most important group is phthalates, chemically speaking compounds of phthalic acid with alcohols (phthalic acid esters). Citrates, adipates and epoxidised soybean oil (ESBO) are also used as plasticisers.

When the European chemicals regulation (REACH) came into force in 2007, around 700 phthalates were registered with the European Chemicals Agency (ECHA). Only a few of them are produced on a larger scale. In 2021, 32 phthalates were manufactured in or imported into Europe in quantities of more than 1 tonne per year.

The most frequently cited phthalates include five substances: DEHP (diethylhexyl phthalate), DBP (dibutyl phthalate), BBP (benzyl butyl phthalate), DINP (diisononyl phthalate) and DIDP (diisodecyl phthalate). Not all of them are assessed in the same way. DEHP, DBP, DIBP (diisobutyl phthalate) and BBP have properties toxic to reproduction that have been demonstrated in animal experiments, which is why their use has been restricted. Over the past 20 years, industry has partly replaced them with DINP and DIDP, which are considered less toxicologically concerning. For DINP and DIDP, animal studies mainly observed effects on the liver.

One point explains why plasticisers become an issue at all: phthalates are not firmly bound in plastic. They can be released from the material and thus get into the environment or into food. According to the BfR, annual consumption of plasticisers in Europe was more than 1.3 million tonnes in 2020. DEHP still accounts for around 40% of total consumption worldwide, because it is produced on a large scale outside Europe.

Plasticisers are found in the greatest quantities in soft PVC, which consists of 30 to 40% plasticisers. Typical applications include cables, films, floor coverings, hoses, sports and leisure articles, medical devices such as infusion tubes, and the lid seals of screw-top jars. Rainwear, artificial leather, nail varnishes and adhesives also contain plasticisers.

Phthalates are mainly taken in through food. Plasticisers are fat-soluble and therefore migrate particularly easily from packaging into fatty foods such as cooking oil, pesto, sausage and cheese. Young children take in more phthalates via house dust and objects they put in their mouths.

The quantities remain small. The BfR does not consider the current phthalate intake of adult consumers to be a significant health risk. The European Food Safety Authority (EFSA) reviewed the substances in 2019. For DBP, BBP, DEHP and DINP combined, EFSA set a tolerable daily intake (TDI) of 0.05 mg per kilogram of body weight. In the European human biomonitoring project HBM4EU, the estimated daily intake of these phthalates via food, inhaled air and skin was 0.1 to 1 µg per kilogram of body weight, i.e. 50 to 500 times below the TDI.

The picture is different for children. The environmental study GerES V estimated the combined intake of the phthalates DBP, BBP, DEHP and DINP. For the majority of 3- to 10-year-olds, it was still above the tolerable daily intake. This is why the use of certain phthalates in food packaging and toys has been banned or severely restricted for years.

Plastic water bottles generally do not contain plasticisers. PET is a plastic that does not need plasticisers. According to the BfR, industry uses neither phthalates nor other plasticisers to manufacture PET bottles. The plastics polyethylene (PE) and polypropylene (PP) do not need any either.

The misconception arises from the name. Polyethylene terephthalate (PET) sounds like a phthalate, but it is not one. The BfR uses the term phthalate exclusively for ortho-phthalates. Terephthalates have a different chemical structure and, according to the BfR, raise far fewer health concerns. There is also a structural difference: plasticisers are merely mixed into the plastic and are not firmly bound. The terephthalate building block, by contrast, is an integral part of the PET polymer chain and cannot be leached out like an additive.

PET is not soft PVC either. In mineral waters, the BfR either did not detect phthalates at all or found them only in very low concentrations. Such small amounts of phthalates do not explain the oestrogenic activity measured. Plasticisers in plastic bottles and PET bottles are therefore not a measurement finding but a confusion of two groups of substances.

Soft plastic bottles are not an official product category but an everyday term for bottles that can be squeezed. Technically, soft plastic usually means soft PVC. Soft PVC is produced when 30 to 40% plasticisers are added to hard, brittle polyvinyl chloride (PVC).

Beverage bottles in Germany are not made of soft PVC. They are made of PET or polyethylene, and neither plastic needs plasticisers. What a bottle is made of is usually stated on it: PET bottles are marked either with "PET" or with the triangular arrow symbol with the number 1.

The fact that a thin-walled single-use bottle can be squeezed is due to the low wall thickness, not to plasticisers in the material.

The difference between plasticisers, bisphenol A, antimony and acetaldehyde lies in their origin, limit value and legal status. The four substances are regularly confused in connection with water bottles.

PET bottles are generally BPA-free. Bisphenol A is not used in the manufacture of PET. In recycled PET bottles, the BfR found small amounts as an impurity, far below the former limit value of 50 micrograms per kilogram of food. According to current knowledge, they do not pose a health risk.

Bisphenol A is not a plasticiser. BPA belongs to a group of substances that can have hormone-like (oestrogenic) effects, and it serves as a starting material for polycarbonate and epoxy resins. BPA is therefore more likely to be found in drinking cups, plastic tableware and drinking bottles made of polycarbonate, as well as in the inner coating of food tins.

The legal situation has changed fundamentally since 2025. Since 20 January 2025, Regulation (EU) 2024/3190 has banned bisphenol A, its salts and other hazardous bisphenols in food contact materials throughout the EU. For end products that were lawfully manufactured before then, a transitional period runs until 20 July 2026.

The claim "BPA-free" only says that a product does not contain bisphenol A. It says nothing about other substances in the material. That is precisely why the EU regulation covers not only BPA but also other hazardous bisphenols and bisphenol derivatives.

According to the BfR's assessment, acetaldehyde from PET bottles is considered harmless to health. Under the regulations in force in the EU, a maximum of 6 mg of acetaldehyde may migrate from plastics into 1 kg of food. Up to this limit value, the BfR rules out adverse health effects. In mineral water, the amounts are generally far below this.

Acetaldehyde (ethanal) is an aldehyde. The substance forms during the manufacture and storage of PET bottles. From there, it migrates into the drink in small quantities. So it is not added, but forms in the plastic itself.

Acetaldehyde is also discussed in connection with alcoholic beverages. The assessment of alcohol concerns a different route of intake and does not apply to mineral water from PET bottles.

Antimony is present in PET bottles as a residue from production. Antimony compounds serve as a catalyst in PET production. In mineral water, the BfR detected up to 2 micrograms of antimony per litre. The European Commission's limit value is 40 micrograms per kilogram of food.

Antimony is a metalloid and, according to the BfR, has very low oestrogenic activity. The measured values remain far below the limit value. Which metals occur in tap water and which limit values apply to them is covered in the guide to heavy metals in tap water.

Hormonally active substances from PET bottles have not been detected to date. Using cell culture test systems and a test on snails, studies found oestrogenic activity in some mineral waters. The measured activity was around 10,000 times lower than the natural oestrogenic activity of milk, beer or red wine.

The debate was triggered by a study carried out at the University of Frankfurt in 2009. Martin Wagner and Jörg Oehlmann tested mineral water for oestrogenically active substances and reported higher activity in water from plastic bottles. The authors were unable to identify which substance caused the activity. The study was criticised by experts.

Today, the BfR assesses the findings differently. A comparison between mineral water from PET bottles and from glass bottles showed no difference in the oestrogenic activity measured in cell cultures. It can therefore not be assumed that the low activity is due to the PET bottles. Chemical analyses of mineral waters have also not yet detected any substances that could have caused the oestrogenic activity.

Microplastics have been detected in mineral water several times, mainly in refillable bottles. Water from refillable glass bottles contained similar amounts of microplastics to water from refillable plastic bottles. Based on current knowledge, the BfR considers it unlikely that plastic particles in food pose health risks.

The particles apparently do not come from the bottle material. According to the BfR, the findings for glass bottles and the material composition of the particles point to contamination during the cleaning and refilling of the refillable bottles. Abrasion from the cap and ageing of the material are also possible sources.

How microplastics can be removed from drinking water is shown in the guide to microplastic filters for drinking water.

According to current assessments, water from plastic bottles is not unhealthy. Antimony at up to 2 micrograms per litre, acetaldehyde and, in recycled material, occasionally bisphenol A have been detected. All measured amounts are far below the limit values for migration into food.

So PET bottles are not toxic. Detecting a substance says nothing about the amount, and it is the amount that determines the risk. In addition, the impurities found do not necessarily come from the packaging material but may be of other origin.

Two practical points remain nonetheless:

• Do not store plastic bottles in the sun or in the heat. Heat and UV radiation encourage substances to dissolve out of the plastic and migrate into the water.
• Do not reuse single-use bottles. Reuse creates fine cracks in the material in which bacteria and germs can settle.

How tap water and mineral water differ in other respects is compared in the guide tap water or mineral water.

Glass bottles are not fundamentally more environmentally friendly than PET bottles. The environmental footprint depends on the type of bottle, the transport route and whether the bottle is single-use or reusable. According to the Umweltbundesamt (German Environment Agency), reusable glass bottles can be refilled up to 50 times and reusable PET bottles up to 20 times.

Reusable beats single-use. According to the Umweltbundesamt, reusable bottles generally require less energy and fewer raw materials than single-use bottles. This applies all the more, the more regional the distribution and the higher the number of refills. Reusable glass bottles are ecologically advantageous; single-use glass bottles are not.

Transport shifts the calculation further. The further drinks travel, the greater the burden on the environment. Brand-specific bottles sometimes travel very long distances, regardless of the material. Reusable PET bottles are much lighter than glass bottles, which has a positive effect on transport. Whether glass or plastic performs better therefore depends on the individual case.

Reusable bottles made of stainless steel and glass are best suited for everyday use. Both are generally free of harmful substances and taste-neutral. The difference between glass, stainless steel and aluminium lies in weight, durability and environmental footprint. Plasticisers play no role in the choice, because drinking bottles do without them. Sustainability, other substances and hygiene are more important.

The cheapest way to fill such a bottle is with tap water. If you want to improve the taste or reduce the pollutant load of your tap water, filter it first. An activated carbon block filter such as the ACTIVE+ cartridge binds chlorine, heavy metals and microplastics, among other things. How activated carbon works in this process and which designs are available is explained in the guide Activated carbon filters for water.