Seven workers have died on the spot after inhaling toxic fumes at an effluent treatment plant at a cotton dyeing unit at Perundurai Growth Centre, an industrial estate about 20 km from Erode.

According to T Mathialagan, District Officer – Fire and Safety, the accident occurred at KPR Mill’s effluent treatment plant that processes wastewater from the dyeing unit.

An electrician working on a water pump in a sunken pit was first overcome by poisonous fumes when a valve broke, releasing waste and fumes from an adjacent tank. A fitter and five other workers also suffocated to death after they climbed into the pit one by one to pull out the earlier victims.

Eleven of the factory workers who rushed to the spot were taken ill and hospitalised, he said. The police have filed an FIR and initiated action against the company.

KPR Mill is a BSE-listed company with integrated operations from processing to garment production. According to information available on the company’s website, the 9,000-tonne-a-year processing unit has a 2.5-million-litre-a-day water treatment plant.

Company officials did not respond to repeated efforts to reach them.

Our Coimbatore Bureau adds: MR Sibi Chakravarthi, Superintendent of Police, Erode, said three senior employees of the plant have been arrested in connection with the incident. A case has also been registered against KP Ramasamy, Chairman, KPR Mill.