The labor ministry on Friday raided an air conditioning component manufacturer in the southern city of Changwon over suspected violations of the workplace disaster prevention law after 16 workers were diagnosed with acute poisoning with a hazardous substance.

The raid into Doosung Co. came after acute chloroform intoxication was reported in the 16 workers showing liver function problems after they were exposed to as high as six times the normally permitted level of the chemical during a product cleansing process.

Following the finding, the labor ministry ordered an immediate halt to the cleansing process.

Chloroform, also known as trichloromethane, is a colorless, volatile liquid. When inhaled by humans at a concentrated level, it can damage the liver.

"Acute poisoning happened in more than 10 workers at the same time from the same cause," a ministry official said. "As this is a very serious case, we conducted the raid swiftly."

Under the newly enacted workplace disaster law, owners and CEOs of companies with five or more employees can face a minimum one-year prison sentence or up to a fine of 1 billion won ($834,654) in the event of serious workplace disasters.

It is the first alleged workplace disaster offence involving industrial diseases. Previous labor ministry probes mainly involved workplace accidents.

Earlier this week, the ministry also suspended the operation of the cleansing unit of the firm's Changwon branch and booked the firm and its CEO for investigations on suspicions of breaching the industrial safety and health law. (Yonhap)