Perfluorooctane sulfonic acid
Sulfonated, nitrated or nitrosated derivatives of hydrocarbons, whether or not halogenated: > Perfluorooctane sulfonic acid, its salts and perfluorooctane sulfonyl fluoride: > Perfluorooctane sulfonic acid
Duty Rate (from China)
Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter
Except as provided in headings 9903.88.13, 9903.88.18, 9903.88.33, 9903.88.34, 9903.88.35, 9903.88.36, 9903.88.37, 9903.88.38, 9903.88.40, 9903.88.41, 9903.88.43, 9903.88.45, 9903.88.46, 9903.88.48, 9903.88.56, 9903.88.64, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(e) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(f)
Products classified under HTS 2904.31.00.00
Perfluorooctane Sulfonic Acid (PFOS)
Perfluorooctane sulfonic acid (PFOS) is a fully fluorinated organic compound with a sulfonate group, classified under HTS 2904.31.00.00 as a sulfonated, halogenated derivative of hydrocarbons. It is used in chemical synthesis and industrial applications, meeting Chapter 29 note (a) for separate chemically defined organic compounds.
Potassium Perfluorooctane Sulfonate
Potassium salt of perfluorooctane sulfonic acid, a chemically defined organic compound with sulfonate functionality. Classified under HTS 2904.31.00.00 per Chapter 29 note on inorganic salts of organic acids staying with the parent compound. Used in specialty chemical manufacturing.
Lithium Perfluorooctane Sulfonate
Lithium salt form of PFOS, recognized as the same chemically defined compound under HTS 2904.31.00.00. The sulfonated perfluorocarbon structure dominates classification per Chapter 29 salt rules. Applied in electrochemical and surfactant formulations.
Perfluorooctane Sulfonyl Fluoride (POSF)
Perfluorooctane sulfonyl fluoride (POSF), the acid fluoride derivative of PFOS, explicitly covered under HTS 2904.31.00.00. This reactive fluorochemical intermediate fits Chapter 29 as a halogenated, sulfonated hydrocarbon derivative.
Ammonium Perfluorooctane Sulfonate
Ammonium salt of perfluorooctane sulfonic acid, classified identically to the acid under HTS 2904.31.00.00 per Chapter 29 salt classification rules. Commonly used in fire-fighting foams and coatings.
Diethanolamine Perfluorooctane Sulfonate
Organic salt formed between diethanolamine and PFOS, classified with the later-occurring sulfonated acid per Chapter 29 note on salts (C)(2). Falls under HTS 2904.31.00.00 as the PFOS component dominates.
PFOS Stabilized with Triethanolamine
Perfluorooctane sulfonic acid with triethanolamine stabilizer added for preservation, permitted under Chapter 29 note (f). Remains classified in HTS 2904.31.00.00 as the stabilizer doesn't change primary character.
High Purity PFOS 99% Technical Grade
Technical grade perfluorooctane sulfonic acid at 99% purity, qualifying as chemically defined under Chapter 29 note (a). Classified in HTS 2904.31.00.00 despite minor impurities not affecting identity.