From a regulatory perspective, most of the attention
has been placed on the two most common types, Pfos and perfluorooctanoic acid(PFOA).
On the manufacturing side, the 3M Company was the first to announce in 2000 that it
would stop making perfluorooctane sulfonate(Pfos), the active compound in Scotchguard and other products,
and one of the older types of PFAS.