Bottled water may be convenient – ​​but here’s how it’s doing to your health

growing distrust towards tap water has helped to turn bottled water in a global prominence, even in countries where public supplies are tested most rigorously. Marketing has touted bottled water as purer, healthier, and more convenient, but scientific evidence tells a different story.

This perception of purity is at the heart of bottled water’s appeal, yet studies show that the product often brings its own risks to both health and the environment.

A 2025 study showed that bottled water may not be as safe as many people believe. Testing of water sold in refillable jugs and plastic bottles found high levels of bacterial contamination.

The findings show that in many places tap water is not only safe but is often more strictly regulated and reliably monitored than bottled alternatives.

In most developed countries, tap water is held to more stringent legal and testing standards than bottled water. Public supplies are monitored daily for bacteria, heavy metals and pesticides. In Britain, drinking water The Inspectorate publishes the results openly. In the US, water suppliers must meet national primary drinking water Regulations overseen by the Environmental Protection Agency. Throughout Europe, water quality is regulated by the European Union. drinking water Instruction.

In contrast, bottled water is regulated as a packaged food product. It is tested less frequently and manufacturers are not required to publish detailed quality information.

Research has identified contaminants in bottled water, including microplasticChemical residues and bacteria. A 2024 study found thousands of plastic particles per liter in some products. Other research shows that bottled water often contains higher concentrations of microplastics than tap water, with possible links to SwellingHormone disruption and formation of particles in human organs.

Plastic bottles may also leach chemicals such as antimony, phthalates, and bisphenol analogs. Antimony is a catalyst used to make PET bottles, and PET is the most common plastic used for single-use beverages. Phthalates are plasticizers that keep plastics flexible. Bisphenol analogs such as BPS or BPF are close relatives of BPA, a chemical used to harden some plastics and line food and beverage cans. These substances can transfer into the water, especially when bottles are stored in hot environments such as a car, delivery van, or in direct sunlight.

Scientists are concerned because some of these compounds may act as endocrine disruptors, meaning they could interfere with the body’s hormone systems. High exposure to some phthalates and bisphenols has been linked to effects on reproductive health, metabolism and development, although levels found in bottled water are generally low and long-term risks are still unclear. Researchers are now exploring what repeated, prolonged exposure to water might mean over time, especially as bottled water consumption continues to rise around the world.

Bottled water is not disinfected. Once opened, microorganisms can grow rapidly. A half-empty bottle left in a hot car can become an ideal environment for the growth of microorganisms. Reusing single-use bottles also introduces bacteria into saliva and the wider environment.

That tap water generally contains beneficial minerals is well documented in public health research. In the UK and other countries, fluoride is added to some supplies to prevent tooth decay. The mineral content in bottled water varies widely, and studies show that children who drink more bottled water have higher rates of dental caries.

How green is your bottle?

It’s also hard to drink too much bottled water on the planet. Global consumption is so high that approximately one million plastic bottles are purchased every minute.

Danish water technology company Aquaporin estimates that producing one liter of bottled water may require up to two thousand times more energy than supplying one liter of tap water. The carbon footprint is also high, averaging around eighty grams of carbon dioxide per liter once bottling, transportation and cooling are included.

The bottled water debate cannot be separated from the broader pressures facing global water supplies. Access to clean drinking water remains an urgent challenge around the world. Climate change, rapid urbanization, industrial pollution and population growth are putting pressure on freshwater resources. UNESCO Warns that more than two billion people already live in areas facing high water stress.

To offer an alternative to bottled water, I’m working with a team of researchers on Solar2Water, a portable solar-powered device that generates clean drinking water directly from the air.

The system is decentralized, producing water at the point of use rather than relying on long pipelines or large treatment plants. Producing water locally helps reduce reliance on single-use plastics and reduces demand on municipal systems.

As pressure on infrastructure increases, decentralized systems that produce clean drinking water at the point of use can complement existing networks. They strengthen resilience during climate shocks, reduce reliance on single-use plastics and provide alternatives for communities where trust in tap water has been damaged.

Bottled water remains essential during emergencies or where tap water is truly unsafe. But in most developed countries it is neither safer nor cleaner than tap water. As climate change and pollution reshape water access, understanding the real difference between bottled and tap water matters more than ever.