On December 26th, 2008, the Indian authorities issued the notification of extension of the anti-dumping duty imposed on imports of caustic soda from China and South Korea (Notification No. 137/2008-Customs, 26.12.2008). This follows the conclusion of a sunset review initiated on November 22nd, 2007. The products subject to investigation are classified under the following HS codes: 2815.1100 and 2815.1200. This duty is effective for a period of five years.
 
On December 19th, 2013, the Indian Directorate General of Anti-dumping & Allied Duties, Ministry of Commerce, initiated a second sunset review of the anti-dumping duty imposed on imports of caustic soda from China and South Korea.

While initiating the sunset review, the Indian authorities decided on January 16th, 2014 to extend up to December 25th, 2014 the existing definitive anti-dumping duty imposed on December 26th, 2008 by Notification No. 137/2008-Customs (Notification No. 03/2014-Customs (ADD), 16.01.2014).
  
On June 18th, 2015, the Indian Directorate General of Anti-dumping & Allied Duties, Ministry of Commerce & Industry, issued its final findings of the sunset review. It recommended the continuation of the existing anti-dumping measure.
 
On August 18th, 2015, the Indian Ministry of Finance issued the Customs Notification of extension of the anti-dumping duty imposed on imports of caustic soda from China and South Korea (Notification No. 42/2015-Customs (ADD), 18.08.2015).
The amount of the duty imposed on goods originating in South Korea is USD 21.90 per dry metric ton, at the exception of the producer M/s Hanwha Chemical Corporation whose exports are not subject to the payment of the duty (when exported by Tricon Energy Limited, USA; for more details, see Table of the notification). The amount of the duty imposed on goods originating in China is USD 48.39 per dry metric ton, at the exception of the producers M/s Shanghai Chlor-Alkali Chemical Co. Ltd (if the exporter is Tricon Overseas Inc., USA) and M/s Tianjin Dagu Chemical Company Limited (if the exporter is Tricon Energy Ltd, USA or Tricon Overseas Inc., USA) whose exports are not subject to the payment of the duty. This duty is effective for a period of five years.

On 7 February 2020, the Indian authorities initiated a sunset review of the antidumping duty imposed on imports of the subject good from China and the Republic of Korea. This follows the application lodged by the Alkali Manufacturers Association of India (AMAI).

On 17 August 2020, the Indian authorities extended the definitive duty on imports of the subject good from China and the Republic of Korea until 17 November 2020 following the initiation of the sunset review.