Water from glass bottles might contain up to 3x more microplastics than plastic bottles.
A recent study tested common beverages in France and consistently found glass bottles had the highest microplastic contamination, significantly exceeding plastic bottles and cans.
Beer topped the list, with small glass bottles averaging 134 microplastics per liter (MPs/L). Lemonades (112 MPs/L), colas (103 MPs/L), and cold teas (86 MPs/L) followed (all in glass), with far fewer MPs (1.5–2.4 MPs/L) in plastic bottles or cans.
Even plain bottled water wasn’t exempt. Glass bottles averaged 4.5 MPs/L. That's 181% higher than plastic bottles, which averaged 1.6 MPs/L.
Most surprising of all? The contamination wasn't from the glass itself. Rather, it came from the bottle caps. Researchers discovered that flakes of polyester-based paint on metal caps shed into the beverages. Uncleaned caps drove contamination levels as high as 287 MPs/L, while cleaning caps greatly reduced microplastic contamination by up to 70%.
It really seems that, as a consumer, there is no easy way out. So what can you do?
Filtered water from a reusable, BPA-free bottle remains your best choice to limit exposure. And recognize potential trade-offs. While glass may contain more microplastic particles, plastic bottles (especially when exposed to heat) generally test higher for PFAS and endocrine-disrupting chemicals like BPA and BPS.