Emission Inventory for PFOS in China: Review of Past Methodologies and Suggestions

Table 2

Three major source pathways of PFOS-related compounds: direct, degradation and residual PFOS.

Category	Subcategory	Applications	Environmental source
PFOS salts	K^+, Li^+, DEA, NH^+4	Surfactant in fire-fighting foam, surfactant for alkaline cleaners, emulsifier in floor polish mist, suppressant for metal plating baths, surfactant for etching acids for circuit boards, and pesticide active ingredient for ant bait traps.	Direct
	Amines	Mist suppressant for metal plating baths
	Ammonium Salts	Mist suppressant for metal plating baths
	Amphoterics	Water/solvent repellence for leather/paper.
PFOS substances (FOSA)	Carboxylates	Antistatic agent in photographic paper.	Degradation
	Amides	Pesticide active ingredient.
	Oxazolidinones	Waterproofing casts
PFOS polymers (FOSE) and higher molecular weight substances	Alcohols, silanes, alkoxylates, fatty acid esters, adipates, urethanes, polyesters, acrylates	Soil/water repellence for carpet, fabric/upholstery, apparel, leather, metal/glass	Degradation and residual
	Copolymers, phosphate esters	Soil/water repellence for carpet, fabric/upholstery, apparel, leather, metal/glass. Oil/water repellence for plates, food containers, bags, wraps, folding cartons, containers, carbonless forms, masking papers