U.S. Customs and Border Protection · CROSS Database · 1 HTS code referenced
Primary HTS Code
2811.22.1000
$31.4M monthly imports
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Ruling Age
35 years
Data compiled from CBP CROSS Rulings, Census Bureau Trade Data · As of 2026-04-28 · Updates monthly
Internal Advice Request No. 9/90 relating to the tariff classification under the Harmonized Tariff Schedule of the United States Annotated (HTSUSA) of a silica product known by the brand name "Durosil"
HQ 086755 September 28, 1990 CLA-2 CO:R:C:G RFC 086755 CATEGORY: Classification TARIFF NO.: 2811.22.1000 Mr. David L. Willette District Director U.S. Customs Service 150 North Royal Mobile, Alabama 36602 RE: Internal Advice Request No. 9/90 relating to the tariff classification under the Harmonized Tariff Schedule of the United States Annotated (HTSUSA) of a silica product known by the brand name "Durosil" Dear Mr. Willette: This request for internal advice was initiated by a letter dated July 19, 1989, from Mr. Frank Harland on behalf of Degussa Corporation. FACTS: The merchandise consists of a hydrated silica containing 7.4 percent bound water. This amount of bound water indicates that the product is significantly hydrated. Moreover, the product has the overall physical characteristics of a silica gel. It is known by the brand name "Durosil." ISSUES: Is the presence and amount of bound water a factor to be considered in determining whether a silicon compound should be classified under the HTSUSA as a silica gel? LAW AND ANALYSIS: Classification of merchandise under the HTSUSA is governed by the General Rules of Interpretation (GRIs). GRI 1 requires that classification be determined first according to the terms of the headings of the tariff and any relative section or chapter notes and, unless otherwise required, then according to the remaining GRIs, taken in order. Under GRI 3(a), when goods are, prima facie, classifiable under two or more headings, the goods shall be classified under the heading that provides the most specific description from among headings providing a more general description (i.e., the goods should be classified under the heading that most clearly identifies them). GRI 6 prescribes that, for legal purposes, GRI 1 to 5 shall govern, mutatis mutandis, classification at subheading levels within the same heading. In view of the above, then, when goods are, prima facie, classifiable under two or more subheadings within the same heading, the goods shall be classified under the subheading that most specifically describes or identifies them. Silica gels are a class of synthetic amorphous silica that can be produced by a variety of methods resulting in a family of silica compounds represented by the general formula SiO2.nH2O. The product is produced by the reaction of two or more ingredients such as sodium silicate and sulfuric acid to produce a new chemical compound containing bound water. The amount of moisture and bound water are intentionally induced to give the final product its desired characteristics. Generally, however, silica gels are technically referred to as highly hydrated (bound water) forms of amorphous silica. Guidance for the general description of silica gel can be obtained from the discussion of silicon compounds in the Explanatory Notes to heading 2811 of the HTSUSA where it indicates that a gelatinous form of amorphous silica gel can be referred to as "hydrated silica." In view thereof, the amount of bound water found in amorphous silica is crucial to the classification of the product under the HTSUSA. Although most silica gels will have a bound water content of greater than 5 percent, there exists no strict, minimum-bound-water-content- cutoff point for the classification of silica gel under the HTSUSA. Heading 2811 of the HTSUSA provides for silicon dioxide. Within this heading, subheading 2811.22.1000 provides eo nomine or specifically for synthetic silica gel. In light of the above, the instant product is properly classified under this subheading. HOLDING: The above-identified product is properly classified under subheading 2811.22.1000, HTSUSA, which provides for silicon dioxide, synthetic silica gel. The general rate of duty is 3.7 percent ad valorem. You should inform the inquirer of this ruling. Sincerely, John Durant, Director Commercial Rulings Division