Press Release

September 1, 2026 The General Manager The Manager Corporate Relations Department Listing Department BSE Limited National Stock Exchange of India Limited Phiroze Jeejeebhoy Towers Exchange Plaza Dalal Street Bandra-Kurla Complex, Bandra (E) Mumbai – 400 001 Mumbai – 400 051 Scrip Code: 500770 Symbol: TATACHEM Dear Sirs, Sub: Press Release Please find enclosed herewith a copy of the Press Release titled “CSIR-CSMCRI study finds Mithapur coastal ecosystem healthy and biodiverse following treated wastewater pipeline transition”. The executive summary along with the study report by CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, is available on the Company’s website. A copy of the press release is also being made available on the Company's website: www.tatachemicals.com. You are requested to take the same on record. Thanking you, Yours faithfully, For Tata Chemicals Limited Jeraz E. Mahernosh Company Secretary (FCS 7008) Encl.: as above TCL/PR/28A/2627/Corporate CSIR-CSMCRI study finds Mithapur coastal ecosystem healthy and biodiverse following treated wastewater pipeline transition ~ Premier national research institute report finds healthy marine ecosystem and strong biodiversity around Tata Chemicals Ltd’s Mithapur plant ~ Mumbai, September 1, 2026: A study by CSIR-Central Salt & Marine Chemicals Research Institute (CSIR- CSMCRI), Bhavnagar, has found the marine ecosystem surrounding Tata Chemicals Limited's (TCL) effluent discharge point at Mithapur to be healthy, stable, and productive. The findings indicate that the coastal ecosystem remains in good health, with water and sediment quality parameters staying within natural ranges. The area continues to support a rich variety of migratory and resident birds, thriving mangrove stands, and diverse plankton communities. The CSMCRI study found that decades of industrial operations and treated wastewater management have co-existed with the sensitive coastal environment, with local conditions governed predominantly by natural marine and tidal processes. The report’s diversity indices indicate healthy vegetation communities with no evidence of environmental degradation. As per the study, 637 birds across 40 species were recorded, including migratory species that use the Central Asian Flyway, highlighting Mithapur's role as a vital stopover for these migratory birds. The sampling station nearest the discharge point recorded the highest bird abundance in the study, including approximately 250 Greater Flamingos. The findings indicate that the local mudflats continue to support feeding activity by a range of bird species. Mangrove stands, dominated by Avicennia marina, were found to be healthy and continue to provide shoreline stabilisation and habitat function. The report found that the plankton community comprised 22 phytoplankton and 23 zooplankton species, indicating a balanced and productive marine food web. On seawater quality parameters, the report found that pH, salinity, dissolved oxygen and biochemical oxygen demand were within ranges typical of a healthy coastal marine environment. This assessment has been undertaken as part of the biennial monitoring requirements associated with the approval of the treated wastewater discharge pipeline project. Following field studies conducted by experts in December 2025 and May 2026, this is the first report submitted under the ongoing monitoring framework. The study, released in August 2026, examined water quality, sediment quality, marine biology, floral diversity, and avifauna across a 10 km radius of the discharge point in the Gulf of Kutch. The Central Salt & Marine Chemicals Research Institute is a premier national constituent laboratory of the Council of Scientific & Industrial Research (CSIR), Government of India. Based in Bhavnagar, Gujarat, CSIR-CSMCRI is an accredited testing laboratory under the National Accreditation Board for Testing and Calibration Laboratories (NABL). It is India’s foremost scientific body on marine ecology, salt technologies, and environmental monitoring. The CSIR-CSMCRI assessment report is available on the Tata Chemicals website and can be accessed here. About Tata Chemicals Ltd. A part of over US$ 180 billion Tata Group, Tata Chemicals Limited, is a leading supplier of choice to Glass, Detergent, Industrial and Chemical sectors. The company has a strong position in the crop protection business through its subsidiary company, Rallis India Limited. Tata Chemicals has world class R&D facilities in Pune and Bengaluru. Website: https://www.tatachemicals.com/ Follow us on: Tata Chemicals Limited | Tata Chemicals Limited | Tata Chemicals Limited | Tata Chemicals Limited | Tata Chemicals Limited For more information please contact: Chintan Joshi Siddharth Kumar | Jophy Joseph Head – Corporate Advocacy, Communications and CSR Adfactors PR Tata Chemicals Ltd Mobile: +91 9902929187 | 77389 55944 Mobile: 9223364761 siddharth.kumar@adfactorspr.com chjoshi@tatachemicals.com jophy.joseph@adfactorspr.com