PFAS chemicals are made up of a chain of linked carbon and fluorine atoms, which do not degrade in the environment.
A 2015 CDC report found endocrine-disrupting PFAS have been detected in the blood of 97% of Americans.
According to CNN, they're used in all sorts of consumer products, including fast food packaging.
Foods that contain a lot of grease -- such as burgers, fries, and cookies -- are prime candidates for wrappers made with PFAS.
While earlier forms of PFAS have already been banned, experts say newer forms appear to have many of the dangerous health effects as the older versions.
What's more, they appear to migrate even faster from the paper to the fast food it wraps.
They've been found in the packaging for Burger King's 'Whopper,' chicken nuggets and cookies, and in McDonald's wrappers for the 'Big Mac,' fries, and cookies.
