Surveillance camera footage shows a Hube Globe employee engulfed by fumes while he worked on a tanker containing hydrofluoric acid at the firm’s plant in Gumi, North Gyeongsang Province, on Sept. 27. / Yonhap

By Na Jeong-ju

A toxic chemical leak from a Hube Globe plant in Gumi, North Gyeongsang Province, on Sept. 27 was caused by a mistake made by workers, according to a surveillance camera recording released Wednesday.

The recording shows two Hube Globe workers working on a tanker to unload hydrofluoric acid just before the accident happened at 3:45 p.m. While attempting to connect a hose to the tanker, one of them slipped, and strong, high-pressured fumes came out, knocking the men over. White gases filled the plant for minutes.

The moments were filmed by a camera installed about five meters away from the scene on the wall of the plant. The workers were seen not wearing any safety gear, even helmets.

They were among five employees killed in the accident. Police said they were supposed to close valves before connecting a hose, but instead went ahead with the valves open in order to save time.

“The recording shows that the leak was caused by an inadvertent human error,” said Seo Un-sik, an officer from Gumi Police Station. “We are looking into whether the company neglected its duty.”

The recording was damaged by heat and fumes, but restored by researchers at the National Forensic Service.

The prosecution said it plans to indict three Hube Globe executives regarding the accident.

Hube Global is a small chemical firm which only has 10 employees. The plant is located inside the Gumi Industrial Complex, which was originally planned for technology companies. The firm is known to have acquired the plant from a tech firm in 2006.

Gumi City is also being investigated for changing rules to attract the chemical firm to the tech cluster, officers said.

The government designated the affected area as a special disaster zone on Monday because damage from the leak had been growing.

Over 3,000 people are known to be suffering from rashes, headaches and respiratory diseases. Crops and fruit on more than 200 hectares of farmlands have withered, and some 3,200 livestock animals have shown symptoms of nausea, according to Gumi City.