Can microplastics from containers make tap water disinfection chemicals more toxic?

What's actually in it

Tap water contains small amounts of disinfection byproducts (DBPs). These form when chlorine used to kill bacteria reacts with organic matter in the water. Common DBPs include trihalomethanes and haloacetic acids. At low levels, they're considered acceptable. But you don't drink tap water in a vacuum.

When you pour tap water into a plastic bottle or pitcher, micro- and nanoplastics shed from the container into the water. Now you've got two types of contaminants mixing together.

What the research says

A 2025 study in Food Chem tested what happens when human cells are exposed to disinfection byproducts and plastic particles at the same time. The combination was far more toxic than either one alone.

The micro- and nanoplastics released from containers amplified the toxic response of DBPs in human cells. Cells exposed to the mix showed more DNA damage, higher oxidative stress, and more cell death compared to cells exposed to just the DBPs or just the plastics.

The researchers believe the plastic particles act as carriers. DBPs bind to the surface of the plastic, concentrating them in one spot. When a cell encounters the particle, it gets a concentrated dose of both the plastic and the chemicals riding on it. Using glass or stainless steel water bottles and pitchers eliminates the plastic half of this problem.