Ammonia gas leaks from Chennai fertiliser unit, 36 under treatment

Residents of nearby villages including Periyakuppam and Chinnakuppam were awakened by the strong odour of ammonia, and many complained of breathlessness, said officials. At least 100 people have been affected so far.

Of the nearly 60 people hospitalised, several received first aid for eye irritation and breathing difficulties. Thirty-six people remain under observation, with six in a government hospital and 30 in private hospitals, as of Wednesday evening, officials said.

Emergency services were deployed soon after the local police were informed of complaints about the ammonia odour. The police and district administration, in collaboration with the industrial unit, arranged ambulances and public transport and nearly 60 people were taken to hospitals.

Following the incident, fear gripped the locals with several families fleeing their neighborhoods. “It was sudden… we started suffering from breathlessness, experiencing intense burning sensation in our eyes, throat, nose, and chest. Several people even fainted. Many of us, who were taken to hospitals, required oxygen support,” said Chandra Bose, one of the residents evacuated from the area.

State Health Minister M Subramanian, who visited the affected area and hospitals on Wednesday, meanwhile, said that all the patients were stable and under-observation.

The Ennore unit of Coromandel International Limited 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 Limited — a part of the Murugappa group — confirmed the incident in a statement.

‘Brought in normalcy at the earliest’

Amir Alvi, president and head, Manufacturing (Fertiliser) and Supply Chain, said, “Our standard operating procedure was activated immediately, and we isolated the ammonia system facility and brought the situation to normalcy in the shortest time.”

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 two-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,” said the statement.

According to a status report by the TNPCB, the gas leak has completely been stopped. “As a result of the gas leak, nearly 60 people from nearby areas like Periyakuppam and Chinnakuppam experienced eye irritation and breathing difficulties. They were treated at Stanley Medical College and nearby private hospitals. Following the incident, two pulmonologists conducted five medical camps in the affected areas to provide healthcare to the people,” said the statement.

A technical committee — comprising members from TNPCB, experts from Indian Institute of Technology (IIT) Madras, officials from the regional office of Central Pollution Control Board (CPCB), National Environmental Engineering Research Institute (NEERI), Central Leather Research Institute (CLRI), and Industrial Safety and Health Directorate (ISHD) — has been formed to carry out an assessment report to the government within 24 hours, and a detailed report within three days, according to the statement.

“Furthermore, the Tamil Nadu government has ordered that the pipelines used for transferring ammonia from ships must be thoroughly repaired and tested before resuming the importation of ammonia. Therefore, it is confirmed that the gas leak has been completely stopped, and the public need not panic about the situation,” the TNPCB statement added.

The fertiliser manufacturing unit has also 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, said officials.

The TNPCB’s inspection team also revealed that the ammonia level in the ambient air to be 3 ppm (2090 microgram/m3 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 National Green Tribunal’s (NGT) southern bench also took suo moto cognisance and directed the TNPCB on Wednesday to file a report, which will be heard on January 2, 2024. The Tuesday incident was not the first of its kind in the region, and follows an oil spill by the Chennai Petroleum Corporation Limited (CPCL) in Manali, which had severely affected the residents and fishermen.