Glass vs plastic water bottles: can the bottle change what's in your water?
on October 09, 2026

Glass vs plastic water bottles: can the bottle change what's in your water?

Yes, it can. Plastic bottles can leach chemicals such as antimony, bisphenols, and phthalates into the water they hold, and migration tends to increase with heat and storage time (Badarou et al., 2025). Glass is inert. It does not leach into or react with the water it holds. Loonen is bottled only in glass, and every batch is tested on a finished-goods basis by accredited third-party labs, with results published by QR code.

Do plastic water bottles leach chemicals?

They can. Leaching is the transfer of chemicals from a container into what it holds. Three groups are the most studied in plastic food and drink packaging:

  • Antimony. A catalyst used to make PET, the clear plastic used for most single-use water bottles. A 2025 systematic review found antimony migrates from PET bottles into water, usually at low levels under normal storage, and at several times higher levels under warm or acidic conditions (Badarou et al., 2025).
  • Bisphenols, such as BPA. The National Institute of Environmental Health Sciences (NIEHS) lists BPA as an endocrine disruptor (NIEHS).
  • Phthalates. Plasticizers that NIEHS also lists as endocrine disruptors. A 2023 review found that bisphenols and phthalates can both migrate from plastic food-contact materials into food and drink (Tumu et al., 2023).
  • Heat and storage time are the factors most consistently linked to higher migration (Badarou et al., 2025).

Do plastic bottles release microplastics into water?

They can. A 2019 study in Water Research found that repeatedly opening and closing screw-cap PET bottles increased the microplastic particles at the bottleneck and cap, with the cap as the main source (Winkler et al., 2019). In the same study, squeezing the bottle did not significantly raise microplastic levels in the water.

Is glass better than plastic for water?

For what the bottle may add to the water, yes. Glass is inert. It does not leach plasticizers, it does not contain the plastic polymers that break down into microplastics, and it does not react with the water. Glass is also infinitely recyclable.

Do glass bottles have more microplastics than plastic?

Some glass-bottled drinks did in one 2025 study. Researchers at France's food safety agency (ANSES) measured microplastics in beverages sold in France and found more particles in some glass-bottled sodas, lemonades, iced teas, and beers than in the same drinks in plastic (Chaïb et al., 2025). The particles matched the polyester-based paint on the outside of the metal caps, not the glass. When the researchers cleaned the caps, particle counts in the drink they tested fell by about 70 percent. Water had the lowest average of all the beverages in the study, at 2.9 particles per liter.

Which drink packaging contains plastic?

More packaging contains plastic than the bottle alone suggests:

  • Plastic bottles, most often PET.
  • Aluminum cans, which are typically lined on the inside with a thin polymer coating so the drink does not touch the metal.
  • Paperboard cartons and corrugate-based packaging, which are typically lined with plastic film to hold liquid.
  • Painted or decorated caps, which can shed paint particles into the drink, including on glass bottles (Chaïb et al., 2025).

Glass is one of the few common beverage containers that does not need a plastic lining.

How is Loonen bottled and tested?

Loonen is spring-sourced, filtered for purity, balanced with minerals, bottled only in glass, and comprehensively tested by accredited third-party labs, with results shared via QR code. Water travels in stainless steel tankers and runs through stainless steel lines and physical membrane filtration. Loonen is third-party certified by NSF.

Our cap is aluminum with a PFAS-free, BPA-free liner that creates a clean, food-grade seal. It's unpainted, avoiding the microplastic shedding linked to decorative finishes. Each cap is rinsed twice in a closed-system cap wash before sealing.

In every batch of Loonen, the microplastic polymers we screen for come back non-detect at the laboratory's reporting limit. Third-party testing on finished goods also covers PFAS, bisphenols, phthalates, and hundreds of other trace contaminants. Scan the QR code on the back label or read the results at loonen.com/pages/test-results.

FAQ

Is glass better than plastic for water bottles?

For what the container can add to the water, yes. Glass is inert, so it does not leach plasticizers or react with the water it holds. Plastic bottles can leach antimony, bisphenols, and phthalates, and migration tends to increase with heat and storage time (Badarou et al., 2025). The cap and testing matter too.

Do plastic water bottles leach chemicals into water?

They can. PET bottles can release antimony, a manufacturing catalyst, usually at low levels that rise with heat and storage time (Badarou et al., 2025). Bisphenols and phthalates, which NIEHS lists as endocrine disruptors, can also migrate from plastic food-contact materials into food and drink (Tumu et al., 2023).

Do glass bottles have more microplastics than plastic?

In a 2025 French study, some glass-bottled drinks such as soda and beer had more microplastics than the same drinks in plastic. Researchers traced the particles to paint on the metal caps, not the glass. Cleaning the caps cut particle counts by about 70 percent. Water had the lowest levels of any beverage tested (Chaïb et al., 2025).

Are aluminum cans plastic-free?

Usually not. Most aluminum beverage cans are coated on the inside with a thin polymer lining that keeps the drink from touching the metal. Paperboard cartons are typically lined with plastic film for the same reason. Glass is one of the few common beverage containers that does not need a plastic lining.

How is Loonen tested?

Every batch of Loonen is tested on finished goods by accredited third-party labs, and results are published at loonen.com/pages/test-results and linked by QR code on the back label. The panel covers microplastics, PFAS, bisphenols, phthalates, and more. The microplastic polymers we screen for come back non-detect at the laboratory's reporting limit.

 

References

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