Two massive leaks of chemical vapor at Hanwha Total Petrochemical’s factory in Seosan, South Chungcheong Province, have affected around 650 people, local authorities said Tuesday.

The company, a 50:50 joint venture of Hanwha General Chemicals and French energy giant Total, faces allegations of attempting to cover up the leakages that occurred at around 11:45 a.m. on May 17 and 5:40 a.m. the next day.

“There were no reports on the accident until the city government called to confirm the first leak, and there was no report on the second leak,” said Seosan Mayor Maeng Jeong-ho.

The company called the fire authorities at around 12:30 p.m. on May 17, about 45 minutes after the leakage, and notified the local government at around 1:30 p.m.

“We plan to take action if the company is found to have infringed regulations. Together with the Environment Ministry and the Guem River Basin Environmental Office, we will first inspect whether the company violated the Toxic Chemicals Control Act and then check aspects such as the quality of exhaust and liquid emitted,” an official of South Chungcheong Province said.

At least 110 metric tons of harmful substances leaked due to the accident, causing nausea, dizziness and eye pain among those nearby.

About 60 tons of residue that includes styrene monomer is currently left in the tank that initially contained 170 tons, the company said.

Styrene monomer is a colorless flammable liquid substance used to manufacture synthetic resins, such as Styrofoam.

The temperature inside the troubled tank soared over 100 degrees Celsius at around noon on May 17, two times hotter than the average range of 50-60 degrees Celsius, said Hanwha Total Petrochemical. Styrene monomer becomes highly flammable at over 65 degrees Celsius.

Minor progressive Justice Party leader Lee Jeong-mi said the company’s decision to assign workers unfamiliar with the task to replace those who are on strike was the root cause of the leaks.

Company workers have been on a strike from April 25 due to wage disputes amid a drop in its operating profit.

Vowing to find out the how the accident occurred and come up with preventive measures, CEO Kwon Hyuk-woong immediately apologized for the leak.

“I deeply apologize to local residents, partner companies and industrial complex near the factory for the chemical vapor leaks. The accident was caused by a rapid rise in temperature of the storage tank. This created a stench, among other problems,” he said in a statement released last week.

“To prevent another accident, we will promptly normalize the tank temperature and block the leak. We have stopped operations and will undergo a precise inspection by a professional agency,” Kwon added. 

By Kim Bo-gyung (lisakim425@heraldcorp.com)