What Is Ammonia Poisoning? Explaining The Chemical Exposure Behind The Tiruvallur Gas Leak

The death toll in the ammonia gas leak at a seafood processing unit in Tamil Nadu's Tiruvallur district has risen to five, with three women migrant workers succumbing on Monday morning after two others died a day earlier. The incident, which left 74 workers affected and 67 still undergoing treatment and medical observation, has drawn attention to the dangers posed by ammonia exposure in industrial workplaces and the health consequences of inhaling the gas.

The accident occurred on June 21 at a private seafood processing and export facility in the Kannigaipair Manjangaranai area near Periyapalayam in Tiruvallur district. According to PTI, an unexpected ammonia leak from a pipeline during routine industrial operations exposed workers present at the site. As authorities investigate the exact cause of the incident and the Tamil Nadu government orders a high-level inquiry, the tragedy has raised a broader question: what exactly is ammonia poisoning, and why can it prove fatal?

What is ammonia poisoning?

Ammonia poisoning occurs when a person is exposed to harmful concentrations of ammonia gas, a chemical widely used across industries, including food processing, refrigeration and manufacturing.

Ammonia is a colourless gas with a strong, pungent odour. While low-level exposure can cause irritation, inhaling higher concentrations can damage the respiratory system and other tissues. The extent of injury depends on the amount of gas released, the concentration in the air, the duration of exposure and how quickly a person receives medical attention.

Because ammonia readily reacts with moisture, it can irritate and damage tissues in the eyes, nose, throat and lungs almost immediately after exposure.

What symptoms does ammonia inhalation cause?

According to a health department bulletin cited by PTI, workers affected in the Tiruvallur incident primarily presented with symptoms associated with ammonia inhalation. These included breathlessness, irritation of the eyes and respiratory tract, coughing, chest discomfort and varying degrees of respiratory distress.

Exposure to ammonia gas can initially cause burning sensations in the eyes, nose and throat. As exposure increases, breathing may become difficult as the respiratory tract becomes irritated. In more serious cases, respiratory distress can worsen significantly and become life-threatening.

The health department said 74 individuals were affected in the incident. Of these, 67 are currently receiving treatment and remain under medical observation, while two individuals have been discharged. Two fatalities were reported on June 21. "As of 7 am on June 22, three additional fatalities have been reported, bringing the number of fatalities to five so far," the bulletin said.

What happened in Tiruvallur?

The ammonia gas leak occurred during routine industrial operations at the seafood processing and export facility on June 21. State Labour Welfare Minister J Mohamed Farvas told the Tamil Nadu Assembly on Monday that an unexpected ammonia leak in a pipeline caused 74 workers, including 70 women, to fall ill.

Emergency medical response teams, district administration officials, police personnel, fire and rescue services and public health authorities were mobilised to manage the situation and provide treatment to those affected.

Farvas informed the Assembly that five women had died in the accident. He said Chief Minister C Joseph Vijay had expressed condolences to the bereaved families and announced a solatium of Rs 2 lakh each from the Chief Minister's Public Relief Fund. The minister also said the government would arrange for shifting the mortal remains to the victims' home town at government expense.

What action has the government announced?

Responding to the tragedy, Farvas, making a statement under Rule 110 in the Assembly, said the chief minister had constituted a joint team comprising officials from the health department and the pollution control board.

According to PTI, the team has been directed to submit a preliminary report within 24 hours and a comprehensive report within three days. The minister assured the House that strict action would be taken against anyone found responsible for safety or operational lapses.

He said accountability would be fixed based on the findings of the high-level enquiry committee and warned that those responsible would face legal consequences. The chief minister has also directed that compensation under the Employees' State Insurance scheme and government relief measures be expedited and provided to affected families without delay.

Farvas further said appropriate steps would be taken to prevent similar accidents in future.

Why does the incident matter?

The Tiruvallur accident has once again highlighted the risks associated with hazardous industrial operations and chemical exposure in workplaces.

According to figures cited by the minister in the Assembly, Tamil Nadu has 54,957 industries employing about 27.65 lakh workers. Of these, 6,609 workers are engaged in hazardous industrial units.

While the exact cause of the ammonia leak remains under investigation, the government has said accountability will be fixed if safety or operational lapses are identified and that steps will be taken to prevent similar accidents in future.

The issue also triggered political exchanges in the Assembly. PTI reported that the minister's statement was repeatedly interrupted, prompting Speaker JCD Prabhakar to ask members to maintain silence while he read out the government's statement. AIADMK general secretary Edappadi K Palaniswami insisted that issues raised by his party be taken up, leading to an argument with the Speaker, who reminded members that the proceedings were being broadcast live. The AIADMK later staged a walkout after it was unable to raise an issue related to the unanimous Assembly resolution on the Mekedatu dam.

While the political debate continued inside the House, the focus of the government's response remains on determining how the ammonia leak occurred, ensuring accountability if lapses are found and providing medical and financial assistance to the affected workers and their families.

(With inputs from PTI)