Tamil Nadu has witnessed its deadliest industrial ammonia gas leak tragedy, which has so far claimed the lives of eight migrant women workers at a private seafood processing unit in Tiruvallur district. Some of the 68 hospitalised workers are in intensive care on oxygen support. Since the 1980s, the State has battled ammonia leaks in factories every few years, mostly in and around Chennai. Other than in Thoothukudi in 2024, where one worker died, such accidents have at worst led to the hospitalisation of large numbers of people with eye irritation and breathing difficulties. There were no casualties even when an estimated 67.638 tonnes of ammonia leaked from the undersea pipeline of a private company in Ennore during Cyclone Michaung in 2023. The scale of the tragedy at St. Peter & Paul Seafood Exports Pvt. Ltd., Tiruvallur, indicates that the colourless pungent gas may have accumulated in the atmosphere at fatal concentrations. The leak occurred when workers were resting in factory accommodation, on Sunday. Had the incident occurred on a working day, the number of people exposed to the leak from the ammonia pipeline to the ice-flake machinery could have been significantly higher.

While a committee comprising the Director of Industrial Safety and Health (DISH), the Member Secretary of the TN Pollution Control Board, and the Additional Director of Public Health is conducting an inquiry, disturbing facts have emerged. The factory reportedly failed to rectify serious deficiencies, pointed out during an earlier DISH inspection, including the absence of a suitable alarm system and fire hydrant. It had also not obtained a revised plan approval for installing an ice-flaking machine. That matter is sub judice. Investigations will reveal whether these shortcomings had any bearing in this tragedy. What is clear, however, is that had the recommendations made by DISH in the Ennore case been universally enforced in factories using ammonia, the scale of the current tragedy could have been contained. DISH had recommended the provision of adequate ammonia sensors in the plant and surrounding areas for early warning, along with water-curtain systems linked to ammonia alarms and fire-water nozzles for ammonia feed pumps to reduce the impact of leaks. The government has now decided to form a committee to inspect all 6,669 hazardous industries. However, numerous checks and balances exist under the Tamil Nadu Control of Industrial Major Accident Hazards Rules, 1994. What is required is strict enforcement through a coordinated approach, stronger penalties for violators, and the political will to act decisively against them.