WASHINGTON — U.S. President Donald Trump has signed a Presidential Proclamation imposing a 15 percent tariff on downstream derivatives of polysilicon, a foundational material for the semiconductor and solar power industries, the White House announced. 

Under the decree signed on August 6, the administration determined that the volume and circumstances of polysilicon derivative imports threaten to impair U.S. national security. In his proclamation, President Trump stated that it is necessary and appropriate to levy the 15 percent import duty to mitigate these national security risks and safeguard the domestic industrial base. 

In tandem with the 15 percent tariff, the order establishes a Minimum Import Price (MIP) framework aimed at curbing low-cost foreign imports and market dumping, primarily from nations such as China. Under these new rules, the minimum import price for raw polysilicon is set at $21 per kilogram. For processed polysilicon derivatives, including polysilicon ingots and wafers, the administration established a floor price of $100 per kilogram. 

The executive action is anchored in the findings of an investigation initiated by the U.S. Department of Commerce under Section 232 of the Trade Expansion Act of 1962. Section 232 grants the President broad authority to restrict imports through tariffs or quotas if the Commerce Department determines that the goods enter the country in quantities or under conditions that threaten national security. 

President Trump emphasized that polysilicon serves as a critical building block underpinning the security of America's semiconductor and renewable energy supply chains. He noted that the protective measures are designed to rebuild domestic manufacturing capacity and foster a resilient domestic ecosystem for the strategic material. 

The executive order provides a 120-day implementation window before taking effect. The new tariffs and minimum import price regulations are scheduled to go into effect at 12:01 a.m. Eastern Time on December 4.