U.S. issues preliminary antidumping determination on Chinese methylene diphenyl diisocyanate (MDI)

On September 16, 2025, the U.S. Department of Commerce (USDOC) issued a notice, making a preliminary antidumping determination on imports of methylene diphenyl diisocyanate (MDI) originating from China. It ruled that the dumping margins of the involved Chinese enterprises range from 376.12% to 511.75%.

The specific details of the preliminary antidumping determination made by the USDOC are as follows:

1. The dumping margin for the following producers/exporters is 376.12%: (1) Both the exporter and producer are Covestro Polymers (China) Co., Ltd. (Shanghai); (2) The exporter is Shandong Mingko Co., Ltd., and the producer is Wanhua Chemical Group Co., Ltd. (Shandong);

2. For other Chinese exporters/producers, the dumping margin is determined to be 511.75% in accordance with the "Adverse Facts Available" (AFA) principle.

In accordance with the relevant legal procedures announced by the USDOC, the USDOC will make a final antidumping determination on imports of methylene diphenyl diisocyanate (MDI) originating from China around January 29, 2026.

On March 11, 2025, the USDOC issued a notice stating that, in response to the application submitted by the Ad Hoc MDI Fair Trade Coalition (whose member enterprises include BASF Corporation and The Dow Chemical Company), it decided to initiate an antidumping investigation into imports of methylene diphenyl diisocyanate (MDI) originating from China in accordance with Sections 701 and 731 of the U.S. Tariff Act of 1930. The involved products fall under the U.S. Harmonized Tariff Schedule (HTSUS) subheadings: 2929.10.8010, 3909.31.0000, 3506.91.5000, 3815.90.5000, 3824.99.2900, 3824.99.9397, 3909.50.5000, 3911.90.4500, 3920.99.5000, and 3921.13.5000.