Section 232 polysilicon and solar-derivative tariffs (15%, from December 4, 2026)
Proclamation 11052 of August 6, 2026 imposes an additional 15% ad valorem Section 232 duty on polysilicon, polysilicon ingots and the derivative products listed in its annexes — the solar-supply-chain inputs from wafers through cells and modules — for goods entered on or after December 4, 2026. For products of Japan, Korea, Taiwan, Switzerland, Liechtenstein and EU members the Section 232 duty plus the Column 1 rate totals 15%; the United Kingdom rate is 10%. The duty stacks on existing Section 301 solar rates and antidumping and countervailing duties unless the proclamation says otherwise.
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Timeline
- AnnouncedExecutive order
Proclamation 11052 signed
A 15% Section 232 duty on polysilicon and its derivatives is set to begin December 4, 2026, with 15% combined caps for listed partners and 10% for the UK.
Official sources
Official sources
Status verified 09/10/2026
Related measures
Section 232 steel tariffs (25%)
National-security tariffs on steel, in place since 2018 and sharply expanded in 2025–26: the rate doubled to 50% in June 2025, country exemptions ended, the duty base now covers the full customs value of derivative articles, and hundreds of downstream products were added. Proclamation 11032 reset the base rate to 25% from June 8, 2026 through December 31, 2027, with a 15% combined floor for listed partners including the EU, UK, Japan and Korea and a 15% transitional rate for certain metal-intensive equipment. Unaffected by the Supreme Court's IEEPA ruling.
Current rate: 25% on steel articles and derivatives (reduced from 50% on June 8, 2026, through December 31, 2027); 15% combined floor for the EU, UK, Japan, Korea, Taiwan, Switzerland, Liechtenstein, Argentina, Ecuador, El Salvador and Guatemala; 10% for derivatives made entirely (at least 85% by weight) from U.S.-smelted steel; USMCA goods dutied on non-U.S. content with a 15% floor
Expires by law:Section 232 aluminum tariffs (25%)
National-security tariffs on aluminum, expanded in lockstep with steel: 50% from June 2025 for all origins, derivative coverage broadened repeatedly, duties assessed on full customs value since April 2026, and — since Proclamation 11032 — a 25% base rate from June 8, 2026 through December 31, 2027 with a 15% combined floor for listed partners and a 15% transitional rate for certain equipment. A July 2026 proclamation lets companies building U.S. primary-aluminum capacity import at half the rate. Unaffected by the Supreme Court's IEEPA ruling.
Current rate: 25% on aluminum articles and derivatives (reduced from 50% on June 8, 2026, through December 31, 2027); 15% combined floor for the EU, UK, Japan, Korea, Taiwan, Switzerland, Liechtenstein, Argentina, Ecuador, El Salvador and Guatemala; 10% for derivatives made entirely (at least 85% by weight) from U.S.-smelted aluminum; half rate for approved onshoring plans
Expires by law:Section 232 copper tariffs (50%)
50% tariffs on semi-finished copper and copper-intensive derivative products, effective August 2025 — the first Section 232 action on copper. The regime was folded into the unified metals framework in 2026: expanded coverage in April, further adjustments and a 15% transitional rate for certain categories in June, running through December 31, 2027.
Current rate: 50% on semi-finished copper and most derivatives; some categories at 25% or the 15% transitional rate
Expires by law: