U.S. President Donald Trump will impose a 15% tariff on certain polysilicon derivative products, citing that imports pose a national security threat by eroding domestic capacity for materials needed in U.S. semiconductor and solar manufacturing.

According to aproclamationissued by Trump on Thursday, the tariff will take effect on December 4 and apply to polysilicon ingots and specified derivatives, including solar cells and certain semiconductor devices; imported polysilicon and its derivatives will also be included in a minimum import price program.

The proclamation states that this Section 232 tariff will replace the narrower safeguard tariffs on solar cells and modules that expire in February. The previous tariffs date back to Trump's first term.

For covered products from Japan, South Korea, Taiwan, Switzerland, Liechtenstein, and European Union member states, the proclamation sets the combined rate of the new tariff and existing duties at 15%. Meanwhile, covered products from the United Kingdom will face a 10% tariff.

The minimum import prices set in the proclamation include: $21 per kilogram for polysilicon, $100 per kilogram for polysilicon ingots and wafers, $0.22 per watt for solar cells, and $0.38 per watt for solar modules.

According to the proclamation, the Secretary of Commerce may adjust minimum import prices based on market conditions or other factors affecting the fair market value of covered products.

The proclamation states: "The action plan in this proclamation will help ensure the commercial viability of U.S. production of polysilicon and its derivatives, which is necessary to meet U.S. economic and national security requirements."

In addition to implementing tariffs and the price floor program, the proclamation directs the Secretary of Commerce to establish a program allowing companies to submit plans to relocate covered product production to the United States in exchange for tariff relief, mirroring asimilar directive。

Trump made on aluminum tariffs. The proclamation states that companies approved to build, renovate, or expand U.S. facilities for covered products may import goods and production equipment needed to establish facilities without paying additional tariffs, provided they make "sufficient progress" on commitments. The Secretary of Commerce will determine the allowable duty-free import volume based on the amount of new investment committed by the company.

The Trump administration has imposed Section 232 tariffs on multiple industries, including previously the semiconductor industry. In January, the President signed a proclamation imposing25% tariffson a small portion of semiconductor imports, primarily advanced computing chips. These tariffs do not apply to chips imported to support the construction of U.S. technology supply chains or to enhance domestic semiconductor derivative manufacturing capabilities.