Samsung apologizes for acid leak at plant that killed worker Samsung apologized on Sunday for the January acid leak at one of its semiconductor plants that killed one worker and injured four others. The event occurred at one of the plants in the Hwaseong area of South Korea. Samsung Electronics Vice Chairman Oh-Hyun Kwon said that as part of the apology, the company plans to revoke its bid to have all of its Hwaseong plants certified as green for another five years, the Yonhap News Agency reported Monday. Kwon also promised that the company would take measures to prevent future accidents, saying that "we plan to overhaul the system in a bid to better make environmentally friendly workplaces." On Jan. 28, a 132-gallon tank of hydrofluoric acid started leaking at the plant. A colorless poison, hydrofluoric acid can burn the lungs and affect the entire nervous system. One person died from exposure. Four others were hospitalized but recovered. Samsung at first claimed the leak was minimal. However, local law enforcement fined the company 1 million Korean won (around $900USD) for waiting too long to report the leak. Samsung also claimed that the acid did not leak into the environment, but a police investigation found that it did seep outside the plant. Seven people, including three Samsung officials, have been arrested on charges of negligence over the acid leak, according to Yonhap. The plants in Hwaseong were certified as "green" in 1998, Yonhap noted, meaning the government was no longer regularly checking them for their environmental impact. This article originally appeared on CNET.