By the end of 2015, harmful substances like polyfluoroalkyl and perfluoroalkyl substances also known as PFASs will be completely eliminated from the US. But another concern raised by environmental health experts is a different group of PFSASs, which also have similar concerning characteristics.

Arlene Blum, a chemist at the University of California, Berkeley, said these new substances are equally persistent. A journal Environmental Health Perspectives-published document known as the Madrid Statement has unveiled about the harmful effects of both, the old and new PFAS chemicals.

These chemicals are the ones that protect you carpets from stains, prevent food from sticking to pans and packaging, repel rain from your coat and also avoid spread of mascara.

"It's a very serious decision to make chemicals that last that long, and putting them into consumer products with high levels of human exposure is a worrisome thing", said Blum. In another document, researchers have stated that it is common industry practice in which phased-out chemicals are replaced with the ones having structurally similar ones.

The researchers in the document have asked for cooperation across the globe to limit the production of these chemicals and to find out safer alternatives. But industry groups continue to assert about the safety of the new alternatives.

Jessica Bowman, executive director of the FluoroCouncil, an arm of the industry group American Chemistry Council, was of the view that there is evidence that short-chain PFASs are not expected to pose significant risk.

Blum said there is not sufficient information that can prove that substitute chemicals are safer than the older versions. In fact, there is a data that unveiled that PFASs with certain cancer, has delayed puberty, decreased fertility and reduced immune system in children.