Polysilicon And Derivatives In The Bullseye For Major New Tariffs And Other Restrictions

After conducting an investigation under Section 232 of the Trade Expansion Act of 1962 of threats to U.S. national security from imports of polysilicon and its derivative products, the U.S. is imposing a stringent set of new tariffs and minimum import prices, effective December 4, 2026, as well as anti-surge restrictions, effective Sept. 22 - December 4, 2026. Notably, the new initiative includes differing requirements for different countries.

Acting by Presidential Proclamation of August 6, 2026, and Commerce Department temporary final rule published Sept. 24, 2026, the new requirements establish minimum import prices (MIPs) on polysilicon and its derivative products (including polysilicon ingots, wafers, solar cells, and modules), a 15% ad valorem tariff on the derivative products, and, effective immediately, restrictions to prevent stockpiling of the covered products before the new MIPs and tariffs take effect. Certain trading partners (the United Kingdom, Japan, Korea, Taiwan, Switzerland, Liechtenstein, and members of the European Union) are eligible for lesser restrictions than those on imports from other countries. Manufacturers of polysilicon and its derivatives, and companies that use these products, primarily in the renewable energy industry, should take steps now to ensure compliance with these significant new restrictions.

The key provisions under the proclamation are as follows:

MIPs for imported polysilicon and derivatives:

• $21 per kilogram (kg) for polysilicon;
• $100 per kg for polysilicon ingots and wafers;
• $0.22 per watt for solar cells; and
• $0.38 per watt for solar modules
• Importers must submit documentation to U.S. Customs and Border Protection (CBP) showing that (1) the first arm’s length sale (or first sale of downstream products made from that merchandise) will occur at or above the MIP, or (2) the first arm’s length sale is covered by fixed terms in a contract entered into before August 6, 2026. If the entered value falls short of the MIP, or the importer fails to provide the required documentation, the full MIP amount applies and stacks on top of the 15% ad valorem tariff described below.

A 15% ad valorem tariff on polysilicon ingots, wafers, solar cells, and modules, with some exceptions:

• Imports from the United Kingdom are subject to a 10% rate.
• Imports from Japan, Korea, Taiwan, Switzerland, Liechtenstein, and members of the European Union are subject to a cap so that the tariff amount, plus the existing standard duty amount, does not exceed 15%. Imports from these countries, as well as the United Kingdom, are eligible for manufacturing drawback claims under section 313 (a) and (b) of the Tariff Act of 1930, provided the article is not subject to an antidumping or countervailing duty order, the article is a product of the named countries, and the polysilicon content is composed entirely of polysilicon sourced in one of the named countries.

The new anti-stockpiling requirements, effective immediately, are intended to prevent a surge in polysilicon imports before the December 4, 2026 MIP and tariff effective date. Commerce and CBP will monitor import volumes to ensure they do not substantially exceed historic averages.

The factors that will be considered include:

• The aggregate volume of polysilicon products the importer has imported since Aug. 6, 2026;
• The weekly average volume of polysilicon products the importer is importing since Aug. 6, 2026;
• The weekly average volume of polysilicon products the importer imported between Jan. 2, 2026, and Aug. 6, 2026;
• The weekly average volume of polysilicon products the importer imported in 2025; and
• The use of affiliates that do not customarily import polysilicon products, or the use of new importers of record to import polysilicon products.

The new requirements impose stringent new restrictions and substantial documentation obligations on importers of polysilicon and derivative products, and all affected businesses must move quickly to ensure full compliance.