Ammonia gas leaks from Chennai fertilizer unit, 10 people hospitalised

Residents of nearby villages such as Periyakuppam and Chinnakuppam were awakened by the strong odour of ammonia and many experienced breathlessness. After the local police were informed of complaints about the ammonia odour, emergency services were deployed. The police and district administration, in collaboration with the industrial unit, arranged ambulances and public transport and at least 30 people were rushed to hospitals.

Some individuals received first aid due to eye irritation and breathing difficulties. According to the Avadi Police Commissionerate, 10 people are still under observation at hospitals.

The Ennore unit of Coromandel International Ltd specialises in the production of ammonium phosphate potash sulphate (APPS), necessitating large quantities of ammonia as a raw material. The facility includes a significant double-insulated ammonium storage tank with a capacity of 12,500 tonnes. Ammonia, typically imported from Iran or Saudi Arabia, is received in liquid form and stored under similar conditions.

Coromandel International Ltd, a part of the Murugappa group, acknowledged the incident in a statement. Amir Alvi, President and Head, Manufacturing (Fertilizer) and Supply Chain, said: “Our standard operating procedure was activated immediately, and we have isolated the ammonia system facility and brought the situation to normalcy in the shortest time.”

This incident is not the first of its kind in the region and follows an oil spill by Chennai Petroleum Corporation Limited (CPCL) in Manali, which had severely affected local residents and fishermen.

The Tamil Nadu Pollution Control Board (TNPCB) released a statement detailing the incident on Wednesday morning. The unit noticed a pressure drop in the pipeline around 11.45 pm and simultaneously detected a pungent odour around the storage terminal and near the material gate, it said. “The unit also immediately visited the pipeline location across the road and observed gas bubbles coming out of the pipeline at about 2 feet from the shore. The unit immediately started depressurising the pipeline by diverting the ammonia vapour to the flare and completed the operation within 20 minutes. The unit monitored the ammonia level in the ambient air near the material gate using a handheld monitor and found that the ammonia level was 28 ppm during the incident,” the statement said.

The TNPCB’s inspection team later revealed the ammonia level in the ambient air to be 3 ppm (2090 microgram/m3 as against a 24-hour average of 400 microgram/m3) at 3.30 am near the Material Gate. The ammonia level near the pipeline leak was also measured at 3 ppm at 3.51 am on Wednesday.

A seawater sample collected at the point of pipeline leakage at 3.49 am showed ammonia levels at 49 mg/l, significantly higher than the marine discharge standard of 5 mg/l. By 4.30 am, a mild ammonia odour was still noticeable near the site and the affected villages.

The unit has been instructed to identify the exact location and extent of pipeline damage within a day and to rectify the same before resuming ammonia transfer, and put the pipeline in operation only with the concurrence of the competent authority, the Tamil Nadu Maritime Board.