Naphthalene Sulfonic Acid Salts from Canada
Sodium salts of naphthalene sulfonic acids act as anionic dispersants and surfactants in dye manufacturing and concrete admixtures. The fused aromatic ring system qualifies as modified aromatic under HTS 3402.39.10.00, forming stable emulsions per Chapter note. Typically powder form for industrial use.
Duty Rate — Canada → United States
14%
Rate breakdown
9903.05.2910%Section 301 (forced labor) — additional 10% ad valorem on products of Canada
Import Tips
• Specify sulfonation degree (mono/di/tri) as it affects classification purity
• Dust hazard precautions required for powder imports
• Distinguish from textile dyeing auxiliaries that may go to 3809