Ministry of Commerce Initiates Sunset Review Investigation on Anti-dumping Measures Against PPS Imports from US, Japan, ROK, and Malaysia

On November 30, 2025, the Ministry of Commerce of China announced the initiation of a sunset review investigation concerning the anti-dumping measures applicable to imports of polyphenylene sulfide (PPS) originating from Japan, the United States, the Republic of Korea, and Malaysia.

I. Background and Application

On November 30, 2020, the Ministry issued Announcement No. 53 of 2020, deciding to impose anti-dumping duties on PPS imports from Japan, the United States, the Republic of Korea, and Malaysia, effective December 1, 2020. The duty rates were set at 23.3% to 220.9%, specifically: 25.2%–69.1% for Japanese companies, 214.1%–220.9% for U.S. companies, 26.4%–46.8% for Korean companies, and 23.3%–40.5% for Malaysian companies. The measures were implemented for a period of five years.

· On October 28, 2021, Announcement No. 34 of 2021 stipulated that Idemitsu Fine Composites Co., Ltd. would succeed Idemitsu Lion Plastics Co., Ltd. in inheriting the applicable anti-dumping duty rate and related rights and obligations.
· On October 14, 2022, Announcement No. 26 of 2022 stipulated that HDC Polyall Co., Ltd. would succeed SK Chemicals Co., Ltd. in inheriting the applicable anti-dumping duty rate and related rights and obligations.
On September 8, 2025, the Ministry received a sunset review application submitted by Zhejiang NHU Special Materials Co., Ltd. on behalf of the domestic PPS industry. The applicant claimed that if the anti-dumping measures were terminated, dumping of PPS imports from Japan, the United States, the Republic of Korea, and Malaysia would likely continue or recur, causing continued or recurrent injury to the Chinese industry. Therefore, they requested the Ministry to initiate a sunset review investigation and maintain the anti-dumping measures on PPS imports from these countries. NHU Swancor New Materials (Zhejiang) Co., Ltd. supported the application.

II. Review and Decision

In accordance with the relevant provisions of the Regulations of the People's Republic of China on Anti-dumping, the Ministry reviewed the applicant's qualifications, information concerning the product under investigation and the like product in China, import volumes of the product under investigation during the period of implementation of the measures, the likelihood of continuation or recurrence of dumping and injury, and related evidence. The available evidence indicates that the applicant complies with the provisions of Articles 11, 13, and 17 of the said Regulations regarding the definition of the domestic industry and its representativeness, and is thus qualified to file the application on behalf of the domestic PPS industry. The investigating authority considers that the claims and prima facie evidence submitted by the applicant meet the requirements for initiating a sunset review.

Pursuant to Article 48 of the Regulations of the People's Republic of China on Anti-dumping, the Ministry has decided to initiate a sunset review investigation on the anti-dumping measures applicable to imports of PPS originating from Japan, the United States, the Republic of Korea, and Malaysia, effective December 1, 2025. The relevant matters are hereby announced as follows:

1. Continued Implementation of Anti-dumping Measures
Upon the recommendation of the Ministry of Commerce, the Customs Tariff Commission of the State Council has decided that during the sunset review investigation period, anti-dumping duties shall continue to be levied on imports of PPS originating from Japan, the United States, the Republic of Korea, and Malaysia in accordance with the scope and rates announced in the Ministry's Announcement No. 53 of 2020, Announcement No. 34 of 2021, and Announcement No. 26 of 2022. The anti-dumping duty rates applicable to companies are as follows:

Japanese Companies:

Toray Industries, Inc. — 26.9%
DIC Corporation — 27.3%
Polyplastics Co., Ltd. — 25.2%
Tosoh Corporation — 25.6%
Idemitsu Fine Composites Co., Ltd. — 33.6%
Sumitomo Bakelite Co., Ltd. — 34.5%
All Others — 69.1%

U.S. Companies:

Solvay Specialty Polymers USA, LLC — 214.1%
Fortron Industries LLC — 220.9%
All Others — 220.9%

Korean Companies:

Toray Advanced Materials Korea Inc. — 26.4%
HDC Polyall Co., Ltd. — 32.7%
All Others — 46.8%

Malaysian Companies:

Polyplastics Asia Pacific Sdn. Bhd. — 23.3%
DIC Compounds (Malaysia) Sdn. Bhd. — 40.5%
All Others — 40.5%

2. Period of Investigation
The dumping investigation period for this review is from July 1, 2024, to June 30, 2025. The injury investigation period is from January 1, 2021, to June 30, 2025.

3. Scope of the Product Under Review
The product under review is the same as that subject to the original anti-dumping measures, consistent with the product scope defined in Announcement No. 53 of 2020. Details are as follows:

· Name of Product Under Investigation: Polyphenylene sulfide, also known as polyphenylene thioether. Abbreviated as PPS.
· Description: PPS is a high-performance thermoplastic resin (and its compositions) whose molecular chain contains the phenylene sulfide group (C6H4S). It possesses excellent properties such as high-temperature resistance, corrosion resistance, radiation resistance, flame retardancy, and electrical insulation, regardless of whether it is modified and/or mixed/additivated with fillers (e.g., glass fiber, minerals) and other agents.
· Main Uses: PPS can be used for fiber spinning, film making, coatings, injection molding, extrusion, alloying, etc. The products are widely used in textiles, automotive, electronics & electrical appliances, machinery, petroleum, chemical industry, aerospace, and other fields.
· Customs Tariff Code: The product is classified under Code 3911.9000 of the Customs Import and Export Tariff of the People's Republic of China. Other products under this code are not within the scope of this investigation.

4. Subject of the Review
This review investigation will examine whether the termination of the anti-dumping measures on PPS imports originating from Japan, the United States, the Republic of Korea, and Malaysia would be likely to lead to the continuation or recurrence of dumping and injury.

5. Registration to Participate in the Investigation
Interested parties may register to participate in this anti-dumping sunset review investigation with the Bureau of Trade Remedies Investigation of the Ministry of Commerce within 20 days from the date of this announcement. Participating interested parties shall provide explanatory materials as per the Reference Format for Registration, including basic identity information, quantities and values of exports to or imports of the product under investigation into China, quantities and values of production and sales of the like product, and details of any affiliation. The Reference Format for Registration can be downloaded from the sub-website of the Bureau of Trade Remedies Investigation on the Ministry of Commerce website.
Interested parties registering for this investigation shall submit electronic versions via the "Trade Remedy Investigation Information Platform" (https://etrb.mofcom.gov.cn) and, as required by the Ministry of Commerce, simultaneously submit written versions. The content of the electronic and written versions must be identical and their formats consistent.
The term "interested parties" in this announcement refers to individuals and organizations as defined in Article 19 of the Regulations of the People's Republic of China on Anti-dumping.

6. Access to Public Information
Interested parties may download the non-confidential version of the application from the sub-website of the Bureau of Trade Remedies Investigation or visit the Trade Remedy Public Information Reading Room of the Ministry of Commerce (Tel: 0086-10-65197856) to search, read, transcribe, and copy it. During the investigation, interested parties may inquire about public case information through relevant websites or visit the aforementioned Reading Room to search, read, transcribe, and copy public case information.

7. Comments on the Initiation
Interested parties wishing to comment on the product scope, applicant qualifications, countries under investigation, or other related issues of this investigation may submit written comments to the Bureau of Trade Remedies Investigation of the Ministry of Commerce within 20 days from the date of this announcement.

8. Investigation Methods
In accordance with Article 20 of the Regulations of the People's Republic of China on Anti-dumping, the Ministry of Commerce may employ methods such as questionnaires, sampling, hearings, and on-site verification to gather information from relevant interested parties and conduct the investigation.
To obtain necessary information for this case, the Ministry of Commerce will normally distribute questionnaires to interested parties within 10 working days from the registration deadline specified in this announcement. Interested parties may download the questionnaire from the sub-website of the Bureau of Trade Remedies Investigation.
Interested parties shall submit complete and accurate questionnaire responses within the specified time limit. The responses shall include all information required by the questionnaire.

9. Submission and Treatment of Information
Interested parties shall submit comments, questionnaire responses, and other information during the investigation process via the "Trade Remedy Investigation Information Platform" (https://etrb.mofcom.gov.cn) in electronic version and, as required by the Ministry of Commerce, simultaneously in written version. The content of the electronic and written versions must be identical and their formats consistent.
If an interested party requests confidential treatment for information submitted to the Ministry of Commerce, it must submit a request stating the reasons. If the Ministry agrees, the interested party requesting confidentiality shall simultaneously provide a non-confidential summary of the confidential information. The non-confidential summary shall contain sufficient meaningful information to enable a reasonable understanding of the substance of the confidential information. If a non-confidential summary cannot be provided, reasons must be stated. If submitted information contains no request for confidential treatment, the Ministry will treat it as public information.

10. Consequences of Non-cooperation
Pursuant to Article 21 of the Regulations of the People's Republic of China on Anti-dumping, interested parties shall faithfully reflect the situation and provide relevant information during the Ministry's investigation. If an interested party does not faithfully reflect the situation or provide relevant information, fails to provide necessary information within a reasonable time, or otherwise seriously impedes the investigation, the Ministry of Commerce may make a determination based on facts available and the best information obtainable.

11. Duration of the Investigation
This investigation commences on December 1, 2025, and should conclude by December 1, 2026 (excluding that date).