A toxic gas leak at a chemical plant, which resulted in four deaths and direct economic losses of 6.09 million yuan ($873,531) in Chizhou, East China's Anhui province, has been officially classified as a major work safety liability accident, provincial authorities said on Friday.

Photo via China Daily

The accident occurred at Anhui Xintai New Material Co on Oct 27, 2025, when a worker entered a confined space – a frozen brine tank – without following the required safety protocols.

At around 8:12 pm, an operator surnamed Zhang, went into the tank to retrieve a pump without authorization, proper ventilation, gas detection, or respiratory protection. Zhang was quickly overcome by high concentrations of nitrogen and other gases, it said.

Subsequent rescue attempts were conducted without adequate personal protective equipment, leading to more casualties. Two co-workers and a workshop director who attempted rescues also succumbed, it added.

The investigation identified the direct cause as the violation of confined space entry procedures and the failure of rescue personnel to use proper protective gear.

Indirect causes included inadequate corporate safety management, insufficient staff training, failure to implement risk controls and hazard inspections, and lapses in regulatory oversight by local authorities.

The workshop director, who died in the incident, was recommended to be exempt from liability. Three company officials – the chairman, general manager, and a deputy general manager – have been released on bail pending further investigation by police and face legal or administrative penalties.

The company will be penalized by the Chizhou emergency management bureau in accordance with the law. Matters concerning potential dereliction of duty by local government personnel have been transferred to the Anhui Provincial Commission for Discipline Inspection and Commission of Supervision for accountability proceedings.