The latest toxic gas leaks may not have caused serious physical harm, but the fact that the culprit companies failed to promptly report to state authorities is raising suspicions of corporate negligence.

Top global firms such as SK Hynix, LG and Samsung are now under fire for failing to manage their staff and abide by safety regulations involving industrial hazards at their domestic plants.

Last Friday, a chlorine gas leak was detected around 10:10 a.m. while five workers were working on the valves in the gas lines at chipmaker SK Hynix’s plant in Cheongju, North Chungcheong Province.

No one was injured during the 30-second toxic gas leak, and the incident was reported to fire officials four hours after the leak, only thanks to an anonymous tip-off.

“Because there was no one injured and it was a minor leak, we came to a conclusion that it did not need to be reported,” the company said in an official statement.

The event, followed by a few others in other parts of the nation including the mixed acid leak at LG Siltron also on Friday, came after Samsung Electronics was hit hard by its clumsy response to a toxic gas leak earlier in January, a case that killed one subcontract worker and injured four others.

President Park Geun-hye has since asked firms to step up with improved countermeasures. Environment Minister Yoon Seong-kyu also showed the government’s willingness to prevent such toxic gas leaks and factory explosions through his visit to LG Chem’s Cheongju plant on March 19.

“To prevent these accidents from occurring, the on-site workers’ consciousness of safety needs to be changed and strict supervision of the company must be in place,” said Lee Hak-seong, a professor at the University of Ulsan told local media.

Despite the reprimands, firms appeared to be anxious only to cover up, with officials at SK Hynix claiming that a person would have to be exposed to at least 1 ppm of chlorine gas for over eight hours to experience bodily damage.

“It shows that these people are more concerned about the numbers and figures, and not how they were inefficiently managing these toxic gases,” one observer said.

Recurrence is another critical issue.

The acid leak at LG Siltron’s Gumi plant, for instance, was the company’s second this month.

The hydrofluoric, nitric and acetic acids at the wafer company leaked when a pipe used to ship waste water from a semiconductor wafer production line had a minor rupture.

The total amount of the leak was enough to fill a small paper cup, which was enough to cause a 30-centimeter-wide discoloration on the floor of the plant.

The country’s No. 4 conglomerate was immediately put into emergency mode soon after its affiliate’s gas leak was known, with its parent firm LG Group withdrawing on Saturday its press release involving LG chairman Koo Bon-moo’s overseas trip scheduled for the Monday edition.

Industry experts are stating that reasons for the repetitive accidents could be rooted from the weak cooperation system established between the conglomerates’ subcontracting firms and their plants as well as insufficient management and supervision of the factories.

Lee Jeong-im, a researcher at Gyeonggi Research Institute, said that the firms must conduct their own safety tests on harmful substances in treatment and set up and operate prevention schemes, with the government also providing various guidelines.

By Cho Ji-hyun (sharon@heraldcorp.com)