Can PET plastic from water bottles and food trays harm your lungs and organs?

What's actually in it

PET (polyethylene terephthalate) is the clear plastic used in water bottles, soda bottles, salad containers, and microwavable food trays. It's the most common food-contact plastic in the world. When PET degrades from heat, sunlight, or repeated use, it sheds microplastics and even smaller nanoplastics into your food and drinks.

A single plastic water bottle can release thousands of nanoplastic particles into the water, especially if it's been sitting in a warm car or reused multiple times.

What the research says

A 2026 review in Part Fibre Toxicol focused specifically on PET plastic particles and their health effects. Unlike general microplastic reviews, this one drilled into PET because it's the plastic people encounter most through food and beverages.

PET particles triggered inflammation in lung tissue, gut lining, and liver cells in lab studies. In the lungs, they activated immune cells called macrophages, which released inflammatory signals that damaged surrounding tissue. In the gut, PET nanoplastics disrupted the intestinal barrier, letting bacteria and toxins leak into the bloodstream.

The liver took a hit too. PET particles caused oxidative stress in liver cells, overwhelming their antioxidant defenses. Over time, this type of damage can contribute to fatty liver disease and chronic inflammation.

The review noted that nanoplastics were far more damaging than larger microplastics because they're small enough to cross cell membranes and accumulate inside cells. Switching to glass or stainless steel water bottles and avoiding heated PET containers are the simplest ways to cut exposure.