Environment authorities conducted overnight operations during the weekend to plug and clean up chemical leaks at a factory where 200 tons of hydrochloric acid escaped.

An evacuation order for 760 residents within a radius of 1.5 kilometers was removed as of Sunday morning after it was issued on Saturday upon the report of the accident.

Hydrochloric acid leaked out of a factory in Sangju, North Gyeongsang Province, 280 kilometers south of Seoul.

The toxic chemical is an aqueous solution of hydrogen chloride, a toxic gas that can harm the eyes and respiratory system.

The police of North Gyeongsang Province have launched an investigation to verify the cause of the leak and the amount of the toxic solution leaked.

“Safety measures at the site are still not fully in place, so the police cannot get inside the factory,” said a police official, adding that the police would refer the case to the National Forensic Service to find the exact cause of the accident.

The police called in officials from the factory operator, Woongjin Polysilicon Co, Ltd., on Sunday to see if there was any fault in maintenance.

The factory, which produced polysilicon, an essential material for photovoltaic cells and semiconductors, had not been in operation for six months due to a decline in business.

A toxic gas leak last September in Gumi, North Gyeongsang Province, which killed five people and affected health and livelihoods of more 1,000 people, had raised fears of possible leaks from chemical factories around the region.

By Kim Young-won (wone0102@heraldcorp.com)