Mr. Frank Podlasinski
Palram Americas
9735 Commerce Circle
Kutztown, PA 19530

RE: The tariff classification of a heat stabilizer from China

Dear Mr. Podlasinski:

In your letter dated November 25, 2019, you requested a tariff classification ruling. Additional information was provided via email on December 5, 2019. The sample received from the previous correspondence will be returned.

SW977, Methyl Tin Mercaptide, is a transparent clear liquid said to be principally used as a heat stabilizer for PVC (polymerizing vinyl chloride) extrusion manufacturing. It consists of dimethyltin bis(2-ethylhexylmercaptoacetate) (CAS No. 57583-35-4) and methyltin tris(isooctyl thioglycollate) (CAS No. 57583-34-3).

In your letter, you propose classification in subheading 2930.90, Harmonized Tariff Schedule of the United States (HTSUS), which provides for “[o]rgano-sulfur compounds: [o]ther.” The instant product is a mixture of the indicated chemicals and is not a "separate chemically defined organic compound." It is excluded from Chapter 29 by Note 1 to Chapter 29.

The applicable subheading for the SW977 will be 3812.39.9000, (HTSUS), which provides for “antioxidizing preparations and other compound stabilizers for rubber or plastics: [o]ther: [o]ther: [o]ther.” The general rate of duty will be 5 percent ad valorem.

Pursuant to U.S. Note 20 to Subchapter III, Chapter 99, HTSUS, products of China classified under subheading 3812.39.9000, HTSUS, unless specifically excluded, are subject to an additional 25 percent ad valorem rate of duty. At the time of importation, you must report the Chapter 99 subheading, i.e., 9903.88.03, in addition to subheading 3812.39.9000, HTSUS, listed above. The HTSUS is subject to periodic amendment so you should exercise reasonable care in monitoring the status of goods covered by the Note cited above and the applicable Chapter 99 subheading. For background information regarding the trade remedy initiated pursuant to Section 301 of the Trade Act of 1974, you may refer to the relevant parts of the USTR and CBP websites, which are available at and, respectively.

Duty rates are provided for your convenience and are subject to change. The text of the most recent HTSUS and the accompanying duty rates are provided on the World Wide Web at

This merchandise may be subject to the requirements of the Toxic Substances Control Act (TSCA), which are administered by the U.S. Environmental Protection Agency (EPA). Information on the TSCA can be obtained by contacting the EPA at Document Control Office (7407M), Office of Pollution Prevention and Toxics (OPPT), Environmental Protection Agency, 1200 Pennsylvania Avenue, N.W., Washington, D.C., 20460, by calling the Toxic Substances Control Act Hotline at (202) 554-1404, by e-mailing to [email protected], or by visiting their website at

This ruling is being issued under the provisions of Part 177 of the Customs Regulations (19 C.F.R. 177).

A copy of the ruling or the control number indicated above should be provided with the entry documents filed at the time this merchandise is imported. If you have any questions regarding the ruling, contact National Import Specialist Fei Chen at [email protected].


Steven A. Mack
National Commodity Specialist Division