It’s the bottle that counts: healthy water drinking

As Stiftung Warentest recently repeatedly confirmed, many mineral waters are not necessarily healthier than tap water. One of the aspects that plays an important role here is the type of bottle in which the water is sold. Reusable bottles are the better choice in purely ecological terms. Glass bottles offer health benefits. Plastic bottles may be easier to handle, but they are often dangerous. In the 2016 summer test, Stiftung Warentest once again found unnecessary harmful substances in PET bottles from conventional mineral water manufacturers, some of which are attributable to the packaging. The potential problem of residues in mineral water from PET bottles has been known for several years.

The PET bottle – what’s behind it?

Currently, for every five mineral water bottles sold in Germany, four are already sold in PET bottles. The abbreviation PET stands for polyethylene terephthalate. In chemical terms, this thermoplastic belongs to the polyester family. There is no question that bottles made of this plastic are easier to handle, less likely to break and much lighter in the shopping or sports bag. In addition, glass bottles are not permitted in most sports facilities. On closer inspection, however, the bottles are often not entirely safe for the water they contain and are also ecologically questionable. The plastic is produced on the basis of crude oil with a fairly high energy input. After all, reusable PET bottles are returned to the cycle. They can be filled up to twenty-five times. However, the maximum fill level for returnable glass bottles is around twice as high. Disposable PET bottles, on the other hand, are recycled at great expense, which in turn consumes large amounts of energy. If plastic bottles are carelessly thrown away, nature can hardly break them down for centuries. Added to this is the migration of pollutants. The latter dissolve from the plastic and thus enter the water. In the long term and with frequent consumption of mineral water from most PET bottles, this has an unpleasant effect on health.

Migration of harmful substances from PET bottles

The mode of action of most substances in plastics has not yet been fully researched. In the majority of mineral waters sold in PET bottles, various hormone-like substances or specifically the hormone oestrogen have been detected. Although the quantities in individual bottles are often still harmless, the long-term effects cannot yet be assessed. The oestrogen content in mineral water from plastic bottles is about twice as high as in mineral water bottles made of glass. Therefore, it cannot be explained by groundwater contamination from animal fattening, industry or private sewage. Hormone-like compounds are mainly used as plasticizers in plastics. These connections make the bottles more flexible. The best known and already relatively well researched is bisphenol A    BPA, genauer „4,4'-(1-methylethylidene)bis(phenol)“, ist im Handel als weißes Pulver mit einem Schmelzpunkt von 158°C.... To prevent additional undesirable substances from being released from PET bottles, a PET water bottle should never be filled with juice or rinsed out hot. The PET bottles used for mineral water are not designed for drinks with a higher acid content. The acid could dissolve compounds from the bottle. Hot rinsing can also lead to the migration of undesirable substances into the tap water that is refilled afterwards. Thinner PET water bottles also shrink when exposed to heat. After that, they are no longer usable and no deposit machine will accept them. Some manufacturers are already dispensing with these plasticizers in their plastic bottles for mineral water. Unfortunately, this criterion is not on the label of the bottle in the shops.

Mineral water from glass bottles or tap water are clearly the better solution in terms of health and environmental aspects. There are now a large number of suppliers offering reusable water bottles made of plastic without plasticizers such as bisphenol A. These are a good alternative, especially when traveling, doing sports or for children. There are also many beautifully shaped glass drinking bottles that can be refilled again and again, some of which are protected by a coating. So drinking can be healthy and ecologically sound.