09/22/2025
A groundbreaking study published in Environmental Science & Technology (ACS Publications, July 2024) found that beverages stored in glass bottles may actually contain significantly more microplastics than those stored in plastic bottles.
This surprising result stems from plastic-based liners and polymer-based cap seals typically used in glass bottles, which can shed microscopic plastic particles into liquids.
The researchers tested three types of bottles—glass, plastic, and paper-based cartons—using filtered water and found:
- Glass bottles contained the highest number of microplastic particles (average ~630,000 particles per liter),
- Plastic bottles followed with fewer (~110,000 particles per liter),
- Cartons had the least (~30,000 particles per liter).
The primary sources of microplastics in glass bottles weren’t the glass itself (which is inert) but the polymer linings in the caps, adhesives, and manufacturing residues.
These findings overturn the common belief that glass is automatically a safer, more inert packaging material compared to plastic when it comes to microplastic contamination.
This revelation raises new concerns about microplastic exposure through food and beverage consumption, especially since these tiny plastic particles can pass through the gut and enter the bloodstream, potentially affecting organs.
Researchers emphasize that while switching from plastic to glass is often done for sustainability reasons, microplastic contamination is a hidden factor that consumers and policymakers need to consider.
Further research is underway to explore safer alternatives to plastic-based bottle components.
