Nitrosylsulfuric Acid (Chamber Acid) from Mexico
Nitrosylsulfuric acid (HNO2SO4), also known as chamber acid, is used in sulfuric acid production and nitrating mixtures. Classified under HTS 2811.19.61.90 as an other inorganic acid, it is a complex oxygen compound of nonmetals (sulfur and nitrogen). Meets Chapter 28 definition for chemically defined inorganic acids.
Duty Rate — Mexico → United States
14.2%
Rate breakdown
9903.05.5510%Section 301 (forced labor) — additional 10% ad valorem on products of Mexico
Import Tips
• Provide detailed chemical composition and CAS number (7782-78-7) in entry docs to distinguish from sulfuric acid in 2807
• Classify as UN 2305 corrosive; use IBC totes with proper placarding to avoid delays