Public health advocates on Thursday demanded federal action to ban the use of toxic “forever chemicals” found in many household products after 100% of breast milk samples were found in a study to be contaminated with the substances.

Researchers at Toxic-Free Future, Indiana University, the University of Washington and Seattle Children’s Research Institute studied 50 samples of breast milk from American women from all over the country, representing a range of socioeconomic backgrounds. All 50 samples contained per- and polyfluoroalkyl substances (PFAS) at levels nearly 2,000 times the amount considered safe for drinking water.

The chemicals do not break down and have been shown to accumulate in humans — including in the food considered by the American Academy of Pediatrics to be the most beneficial for babies.

The group called on state and federal lawmakers to ban the use of PFAS, which are found in food-packaging, non-stick cookware, water-proof clothing and stain guards like ScotchGard.

Toxic PFAS Chemicals Found in 100% of Breast Milk Samples • Children’s Health Defense