U.S. Launches Final Phase of Investigation on Chinese Chemical Imports
Estimated reading time: 3–5 minutes
The United States International Trade Commission (ITC) has started the final phase of its antidumping investigation on methylene diphenyl diisocyanate (MDI) from China. This chemical is used in many products and industries. The notice was published in the Federal Register on September 25, 2025.
About the Investigation
The case is called Investigation No. 731-TA-1733 (Final). The investigation checks if imports of MDI from China are hurting U.S. companies. The ITC is acting under the Tariff Act of 1930.
MDI from China is said to be sold in the United States at less-than-fair-value prices. The Department of Commerce has already made a “preliminary determination” about these imports. The ITC must now decide if U.S. companies are injured or threatened by these imports.
What is MDI?
MDI stands for methylene diphenyl diisocyanate. It is an aromatic chemical used in many goods. Its other names include Polymeric MDI, Monomeric MDI, and Modified MDI.
MDI is made of two or more isocyanate groups attached to benzene rings, joined by methylene bridges. It has many Chemical Abstracts Service (CAS) numbers. The most common numbers are 9016-87-9 and 101-68-8.
MDI can be a liquid or a solid. It is included under various Harmonized Tariff Schedule (HTSUS) numbers like 2929.10.80 and 3909.31.00. If a mixture contains less than 40% MDI by weight, it is not covered by this case.
Some partially reacted forms of MDI are not included if their NCO content is under 10% by weight.
MDI Products and Processing
MDI may have additives such as catalysts, plasticizers, or fire retardants. MDI processed in another country but matching the description is still covered. This includes blending or adding additives.
Blends with MDI from countries not under investigation are covered, but only the Chinese MDI in the mix is subject.
Background of the Case
This full investigation started after BASF Corporation and The Dow Chemical Company filed a complaint as the MDI Fair Trade Coalition on February 12, 2025. Both companies are large chemical producers in the United States.
How to Participate
The ITC has set out rules for those wanting to take part. Anyone who wants to have a say in the investigation must file an “entry of appearance” 21 days before the hearing. The staff report will be ready on January 12, 2026.
The public hearing is on January 27, 2026, starting at 9:30 a.m. in Washington, DC. Requests to join the hearing must be filed by January 21, 2026. There are rules for appearing by videoconference, especially if someone is sick.
Written submissions, including statements for or against the petition, must be sent by February 3, 2026. The final date for responding to released information is February 24, 2026. No paper filings will be accepted; everything must be sent electronically.
Access to Information
Business confidential information will be protected and handled under special orders. Parties must apply to see this information 21 days before the hearing.
Who Is In Charge?
The notice is issued by Sharon Bellamy, Supervisory Hearings and Information Officer at the ITC.
Legal Basis
The investigation follows Section 735(b) of the Tariff Act of 1930 (19 U.S.C. 1673d(b)). All procedures are described in parts 201 and 207 of the ITC’s rules.
Contact Information
Questions can be directed to Lawrence Jones at the ITC Office of Investigations, (202) 205-3358.
Learn More
Full details and updates for the case can be found on the ITC’s website: https://www.usitc.gov. For the public record, see https://edis.usitc.gov.
Key Dates to Remember:
- Prehearing staff report: January 12, 2026
- Deadline to appear at hearing: January 21, 2026
- Public hearing: January 27, 2026
- Final written statements: February 3, 2026
- Final comments on released information: February 24, 2026
This investigation may affect the imports of MDI from China and could impact U.S. chemical companies and industries that use MDI.
Legal Disclaimer
This article includes content collected from the Federal Register (federalregister.gov). The content is not an official government publication. This article is for informational purposes only and does not constitute legal advice. For case-specific consultation, please contact us. Read our full Legal Disclaimer, which also includes information on translation accuracy.
