The U.S. Department of Commerce has commenced an investigation to determine the effects of importing polysilicon and its derivatives on the country’s national security.

The investigation aims to assess the potential for export restrictions by foreign nations, including their ability to weaponize their control over polysilicon and its derivatives.

Polysilicon is a key material used in the production of solar cells and modules.

Commerce has invited interested parties to submit written comments, data, analyses, or other information pertinent to the investigation to the Department’s Bureau of Industry and Security and Office of Strategic Industries and Economic Security.

Commerce stated that it is specifically interested in comments and information on the criteria listed in Section 705.4 of the National Security Industrial Base Regulations. The required comments/information include, but are not restricted to, the following:

• The U.S.’s current and projected demand for polysilicon and its derivatives
• The extent to which domestic production of polysilicon and its derivatives can meet domestic demand
• The role of foreign supply chains, particularly of major exporters, in meeting the U.S. demand for polysilicon and its derivatives
• The concentration and associated risks of U.S. imports of polysilicon and its derivatives from a small number of suppliers
• The impact of foreign government subsidies and predatory trade practices on the competitiveness of polysilicon and its derivatives in the U.S.
• The economic impact of artificially suppressed prices of polysilicon and its derivatives due to foreign unfair trade practices and state-sponsored overproduction
• The feasibility of increasing domestic capacity for polysilicon and its derivatives to reduce import reliance
• The impact of current trade policies on domestic production of polysilicon and its derivatives, and whether additional measures, including tariffs or quotas, are necessary to protect national security

Commerce has not named any particular country from which polysilicon enters the U.S. China dominates the global polysilicon supply chain.

Last December, the United States Trade Representative announced final modifications to Section 301 tariffs, which increased duties on specific Chinese imports. A 50% tariff on polysilicon imports took effect on January 1, 2025.

In January this year, China’s Ministry of Commerce said it was initiating a sunset review investigation into anti-dumping duties applicable to solar-grade polysilicon imports from the U.S. and South Korea starting January 14, 2025.