CLA-2 CO:R:C:F 951740 EAB

Area Director
New York Seaport
U.S. Customs Service
6 World Trade Center
New York, New York 10048

Re: sodium aluminosilicate; complex silicates; ion exchangers; 2842; 3823

Dear Ms. Maguire:

This ruling is in reply to Chief, NIS Division, Branch 1, New York Seaport Memorandum dated April 24, 1992 (CLA-2-8:S:N: N1:235/873257) concerning the classification under the Harmonized Tariff Schedule of the United States Annotated (HTSUSA) of sodium alumino-silicate.

FACTS:

The merchandise is identified as sodium aluminosilicate. There is no indication of its use or structure.

ISSUE:

Which complex silicates are classifiable under heading 2842 and which are classifiable under heading 3823?

LAW AND ANALYSIS:

Legal Note 1(a), Chapter 28, provides that except where the context otherwise requires, the headings of that chapter apply only to separate chemically defined compounds.

Sodium aluminosilicate belongs to a class of compounds known as "zeolites," which are complex silicates. Generally amorphous in structure, the compounds are held together by electrostatic forces and hydrogen bonds rather than true chemical bonding, and it is this "zeolitic bond" that characterizes the class. Upon seeding, a crystalline structure produces a compound that is used as an ion exchanger. Legal Note 5, Chapter 28, provides that except where the context otherwise requires, double or complex salts are to be classified under heading 2842.

For the purposes of classifying inorganic compounds within chapter 28, when Legal Note 1(a) is taken in context with Legal Note 5, we are of the opinion that complex salts such as aluminosilicates are usually classified under heading 2842. We believe that is the result intended by the interpretive language of Explanatory Note (EN) 28.42 II (K), which identifies aluminosilicates as a member of that class of inorganic compounds described as "double or complex salts" covered by heading 2842. As that EN demonstrates, numerous compounds not found in the technical literature as separate chemically defined compounds may be classified in Chapter 28 under heading 2842.

As noted above, Legal Note 5 itself contains an exception. We believe that exception, taken in context, means that aluminosilicates that are used as ion exchangers are classifiable in heading 3823. Chapter 38 covers miscellaneous chemical products; heading 3823 includes, among other goods, chemical products and preparations of the chemical or allied industries not elsewhere specified or included. Subheading 3823.90.39 is a residual provision under which ion exchangers are to be classified. See Explanatory Note 38.23B(14).

In conclusion, it is our opinion that amorphous complex silicates are usually classifiable under subheading 2842.10.00. If they have been crystallized for adaptation as ion exchangers, then they are products of the chemical or an allied industry and classifiable under subheading 3823.90.39, HTSUSA.

HOLDING:

Amorphous sodium aluminosilicate and other similar complex silicates are classifiable under subheading 2842.10.00, HTSUSA, and are dutiable at the column one general rate of 3.7 percent ad valorem.

Complex silicates that have been crystallized to be used as ion exchangers are classifiable under subheading 3823.90.39, HTSUSA, and may be entered free of duty.

You are requested to forward to this office copies of any previously issued rulings which may be contrary to this decision.

Sincerely,

John Durant, Director