Leaching of Chemicals and Microplastics from PEX Pipes

The Hidden Costs of Plastic Plumbing

Plastic piping, including PEX, PVC and others, is now used in over half of all plumbing systems globally. While sometimes praised for its corrosion resistance, real-world exposure to disinfectants like chlorine can initiate chemical degradation of plastic pipes and the release of microplastics (MPs), nanoplastics (NPs), and volatile organic compounds (VOCs) into drinking water. Long-term contact with chlorinated water depletes antioxidants in the pipe wall, degrades the polymer matrix and causes physical cracking. These stressors are intensified by temperature, water pressure and pipe age, all of which increase the likelihood of plastic particle release.

More Than Just Microplastics

PEX leaching isn’t limited to physical fragments. Research shows that plastic pipes can also release a mix of chemical additives, including phthalates, alcohol ethoxylates, tert-butyl alcohol, and methyl tert-butyl ether, some of which persist in drinking water for months. These leachates aren’t just aesthetic nuisances affecting taste and odor, they include known endocrine disruptors and potential carcinogens.