The accident occurred after a worker fell into a pool of poisonous waste paper pulp and his colleagues rushed to help him. Several died while trying to rescue the worker.
The accident occurred at around noon in the city of Changde in Hunan Province, the local government said. They vowed to punish those who should be held accountable.
Meanwhile, the death toll from the Tianjin warehouse explosions today rose to 146, state-run Xinhua news agency reported on China's worst industrial accident.
China's cabinet has promised a rigorous and thorough investigation into the deadly blasts that ripped through a warehouse on August 12 in the northern port city of Tianjin where hundreds of tonnes of toxic chemicals were stored, including around 700 tonnes of sodium cyanide.
While nearly 30 people are still missing, over 500 people remain in hospital after the huge explosions, which also seriously damaged two residential compounds nearby and gutted more than 3,000 new cars in a parking area close to the site.
China sacked the head of its work safety regulator for suspected corruption this week.
Yang Dongliang, currently under corruption investigation, was dismissed from his post as director of the State Administration of Work Safety.
