Polysilicon Investigation Launched; Commerce Requests Comments

Today the U.S. Department of Commerce released notice of a newly initiated investigation into the national security implications of imported polysilicon and derivatives of polysilicon, such as polysilicon wafers used in semiconductors and solar cells. To inform Commerce’s assessment, it has requested public comments, due August 6, 2025. By statute, remedies under Section 232 of the Trade Expansion Act of 1962 (Section 232) may vary significantly, potentially including tariffs, quotas, price floors, subsidies, and/or industrial policy.

Commerce’s brief initiation notice does not clearly define how far down the supply chain “derivatives” will reach or address potential overlap between this investigation and the previously-initiated Section 232 investigation concerning semiconductors. In addition to commenting on the scope and remedy, interested parties may also address factors relevant to Commerce’s national security analysis.

Scope and Request for Comments

The notice does not further define the scope of products covered by this investigation, either by description or by reference to HTSUS codes. One major downstream use for polysilicon is, of course, in crystalline silicon photovoltaic cells, a.k.a., solar cells, which have featured frequently in antidumping, anti-subsidy, and safeguard proceedings. These may be covered as derivative products, but formulating the investigation as focused primarily on polysilicon could permit Commerce to cover much of the core of the solar cells supply chain. Notably, although silicon appears on the list of critical minerals published by the U.S. Department of Energy, it does not appear on the U.S. Geological Survey’s list, which controls the scope of the ongoing Section 232 investigation into processed critical minerals. However, and by contrast, polysilicon is used in semiconductor production, which is subject to its own Section 232 investigation. Parties may wish to comment on the potential overlap between these proceedings, particularly if there are differences in the remedy made available under each investigation.

In substance, Commerce’s request for comments echoes its requests in other recently initiated Section 232 investigations into commercial aircraft, medium- and heavy-duty trucks, semiconductors, and pharmaceutical products. The topics highlighted for comment include:

1. Current and projected U.S. demand;
2. U.S. production capacity and the feasibility of increasing U.S. capacity;
3. The role of foreign supply chains, particularly of major exporters, in meeting U.S. demand;
4. The concentration of U.S. imports from a small number of suppliers and the associated risks;
5. The impact of foreign government subsidies and predatory trade practices on U.S. polysilicon and derivative industry competitiveness;
6. The economic impact of suppressed prices due to unfair foreign trade practices and state-sponsored overproduction;
7. The potential for export restrictions by foreign nations, including the ability of foreign nations to weaponize their control over supplies of polysilicon and its derivatives; and
8. The impact of current trade policies on domestic production, and whether additional measures, including tariffs or quotas, are necessary to protect national security.

As in other recent Section 232 investigations, commenters are invited to comment upon other relevant factors as well. In particular, commenters might choose to address the structure of any potential remedy or tariff and how it might be structured with respect to polysilicon derivative products.

Potential Timeline

Commerce’s notice states that this investigation was initiated on July 1, 2025. The statute therefore provides Commerce until March 28, 2026, to conclude its investigation and transmit a report to the President. Commerce may, however, decide to move faster, and its relatively short public comment period suggests an intention to do so.

Once Commerce’s report has been transmitted, the President has up to 90 days to determine whether imported products subject this investigation threaten to impair U.S. national security and determine a response, as well as a further 15 days to implement any such actions. Again, however, the President may determine to move more quickly.

Section 232 actions under the second Trump Administration have thus far resulted in 50% tariffs on steel and steel derivative products, aluminum and aluminum derivative products, and 25% tariffs on automobiles and automobile parts. The President has signaled an intention to impose 50% tariffs on copper and potentially copper derivatives. There is no guarantee that the new investigation will have a comparable outcome, but past actions provide some indication of the level of tariff treatment that the President views as necessary to address imports in the Section 232 context. That said, there is no statutory requirement that the President impose any tariffs in response to a Section 232 report.

Preparing Supply Chains, Opportunities to Engage

Cassidy Levy Kent’s attorneys, economists, compliance experts, and licensed customs brokers help companies develop strategic responses to the latest changes in U.S. tariff policy and plan for potential developments. Cassidy Levy Kent has extensive experience counseling clients to plan compliant supply chains that manage tariff risks, and we routinely assist with preparing and filing comments for consideration in Section 232 investigations. Our team’s deep familiarity with trade law and policy enables clients to adapt and stay ahead of the curve. Cassidy Levy Kent’s attorneys have also been on the frontlines of trade cases involving all aspects of the solar energy supply chain.