💾 Data Updated: Latest version • Last updated: December 09, 2025

9902.05.40 - Tetrakis(hydroxymethyl)phosphonium sulfate (CAS No. 55566-30-8) (provided for in subheading 2931.90.90)

Details

FieldValue
Unit of QuantityN/A
General Rate of Duty (Column 1 - General)Free
Special Rate of Duty (Column 1 - Special)No change
Column 2 Rate of DutyNo change
Quota QuantityN/A
Additional DutiesN/A
About Duty Rates: Rates are divided into Column 1 and Column 2. Column 1 is subdivided into General (normal trade relations rates for all countries not eligible for special programs) and Special (preferential rates for countries with free trade agreements or preference programs). Column 2 rates apply to products from Cuba, North Korea, Belarus, and Russia. When no special rate exists for a classification, General rates apply.

Overview

This HTS category, 9902.05.40, specifically classifies Tetrakis(hydroxymethyl)phosphonium sulfate (THPS), identified by CAS No. 55566-30-8. This chemical compound is typically used as a biocide in industrial water treatment, as a flame retardant, and in textile finishing processes. Its unique chemical structure and specific applications differentiate it from other classifications.

As a provision within Chapter 99, this code signifies a temporary measure or a special classification arrangement. It is important to note that this THPS classification is for the purpose of specific trade agreement provisions or temporary legislation and is *provided for* in subheading 2931.90.90, which covers other organo-inorganic compounds. This means that while THPS has a primary classification under 2931.90.90, its importation under certain circumstances or trade agreements may be subject to the temporary rules and duties outlined in this Chapter 99 code.

Given that this is a leaf node, there are no further subcategories. Classification under 9902.05.40 is therefore definitive for THPS when imported under the conditions stipulated by the temporary legislation or trade agreement provisions associated with Section XXII. Importers should ensure they are aware of the specific trade conditions that necessitate the use of this special classification code, as it is distinct from the general chemical classification.

Frequently Asked Questions

›What is HTS code 9902.05.40?
HTS code 9902.05.40 covers Tetrakis(hydroxymethyl)phosphonium sulfate (CAS No. 55566-30-8) (provided for in subheading 2931.90.90) under the US Harmonized Tariff Schedule. It falls under Chapter 99: Temporary legislation; temporary modifications proclaimed pursuant to trade agreements legislation; additional import restrictions proclaimed pursuant to section 22 of the Agricultural Adjustment Act, as amended.
›What products are classified under 9902.05.40?
This classification covers Tetrakis(hydroxymethyl)phosphonium sulfate (CAS No. 55566-30-8) (provided for in subheading 2931.90.90). It falls under Chapter 99: Temporary legislation; temporary modifications proclaimed pursuant to trade agreements legislation; additional import restrictions proclaimed pursuant to section 22 of the Agricultural Adjustment Act, as amended.
›What is the import duty rate for 9902.05.40?
The general rate of duty for HTS 9902.05.40 is Free. Special preferential rates may apply: No change. The Column 2 rate is No change.

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