pfbs and pfos, a surfactant, chemical formula and skeletal structure

acid background bioaccumulative black chemical chemistry composition compound element fluorocarbon fluorosurfactant formula geometric illustration isolated model molecular molecule nonaflate organic perfluorobutanesulfonic perfluorooctanesulfonic persistent pfbs pfos poison pollutant replaced research science skeletal solid stable structural structure substance sulfonic surfactant synthetic toxic unreactive vector white