Group 1 - The Mexican Ministry of Economy announced the initiation of the sixth sunset review investigation for anti-dumping on liquid caustic soda originating from the United States, with the investigation period from April 1, 2024, to March 31, 2025, and the damage investigation period from April 1, 2020, to March 31, 2025 [1] - The current anti-dumping duties remain effective during the investigation period, and interested parties have 28 working days from the announcement date to register their responses and submit comments and evidence [1] Group 2 - Mexico initiated the anti-dumping investigation on liquid caustic soda from the United States on November 8, 1993, and issued a final ruling on July 12, 1995, imposing anti-dumping duties on products priced below the minimum price of $147.43 per metric ton, with a maximum duty of $38.89 per metric ton, corresponding to a dumping margin of 35.83% [2] - Mexico has conducted three subsequent sunset reviews, with the third review on January 3, 2012, extending the anti-dumping measures for another five years, setting a new minimum price of $288.71 per metric ton and a maximum duty of 54.79% [2] - The fourth and fifth sunset reviews were completed on July 29, 2016, and July 27, 2021, respectively, with the latter maintaining the measures established in the third review, effective from July 13, 2020, for another five years [2] Group 3 - On December 3, 2021, Mexico initiated a period review investigation for anti-dumping on liquid caustic soda from the United States, with a preliminary ruling on August 18, 2022, maintaining the minimum price of $288.71 per metric ton and imposing anti-dumping duties not exceeding 54.79% on products priced below this threshold [3] - On May 29, 2025, the Mexican Ministry of Economy announced a final ruling to adjust the anti-dumping measures from a minimum price system to a direct anti-dumping tax of $195 per metric ton on 100% concentration liquid caustic soda, effective from July 27, 2021 [3]