There are two extreme narratives regarding PET bottles: saying they are ‘completely harmless’ or that ‘they turn into poison if left in the sun’ both oversimplify the picture. Scientific data provide a more balanced message.
Why is antimony being discussed?
Antimony compounds can be used as catalysts in PET production, and very small amounts can migrate into the beverage. Studies show that high temperature and long storage duration can increase antimony migration. However, the majority of measurements under normal storage conditions remain below regulatory limits.
Why is leaving it in a hot car not a good idea?
Under experimental conditions around 50 °C, antimony levels have been shown to increase compared to room temperature. This does not mean that drinking a bottle of water on a single hot day equates to ‘poisoning’; however, not leaving drinking water at unnecessarily high temperatures for extended periods is a sensible precaution.
What does the WHO limit say?
The World Health Organization provides a guideline value of 20 µg/L for antimony in drinking water and states that reported concentrations in drinking water are generally below 5 µg/L. In PET bottle studies, results vary depending on the product, temperature, and duration.
4 practical rules in daily life
- Store bottles in a cool place out of direct sunlight.
- Do not make a habit of drinking beverages that have been left in a hot car for a long time.
- Do not use bottles with damaged packaging or noticeable deformation.
- Instead of continuously refilling a single-use PET bottle, opt for a suitable, cleanable water bottle.
Summary: There is no need to panic; proper storage conditions are an adequate and feasible precaution. In science, what matters is not a single ‘scary’ measurement, but evaluating real-life exposure within regulatory limits and overall risk.
