A fire broke out at the M15X plant on SK hynix's Cheongju 4 Campus, forcing thousands of employees to evacuate. Following a fire and fluorine leak at the same Cheongju 4 Campus on the 1st and a chemical-related incident on the 10th, the fire on this day has heightened concerns over on-site safety management systems.
According to SK hynix and fire authorities on the 12th, a fire occurred at about 9:55 a.m. in the second-floor gas room of M15X at SK hynix's Cheongju 4 Campus in Heungdeok-gu, Cheongju, North Chungcheong Province. Immediately after the fire, employees in M15 and M15X evacuated to the outside.
M15X is a next-generation DRAM production hub that SK hynix is building to meet demand for artificial intelligence (AI) chips. It is considered a core facility tied to the expansion of high-performance memory production, including high bandwidth memory (HBM). The adjacent M15 is a NAND flash-focused production line and has served as the existing memory production hub at the Cheongju business sites.
The fire was reportedly extinguished early by the company's firefighting and disaster prevention team. Cheongju City, concerned about a possible fluorine leak, sent an emergency alert advising nearby residents to avoid the area and asking vehicles to detour. Fire authorities are checking on site whether there was an actual gas leak.
SK hynix believes the fire occurred during gas-related work and is verifying the exact cause and whether production equipment was affected. An SK hynix official said, "Initial suppression has been completed, and we are identifying additional damage."
A fire also broke out at SK hynix's Cheongju 4 Campus on the 1st. At the time, a blaze erupted in a sixth-floor gas room connecting the M15 and M15X plants, and some fluorine leaked, prompting the emergency evacuation of about 3,600 employees. Some employees reported symptoms such as eye irritation and received treatment at the in-house clinic.
On the 10th, a liquid presumed to be TMAH (tetramethylammonium hydroxide) was found at the Cheongju business sites, and two workers were taken to a hospital. TMAH is a chemical used in semiconductor manufacturing processes. Subsequent measurements by the relevant authorities reportedly determined it was not a hazardous chemical.
On the 27th of last month, sparks flew from semiconductor processing equipment inside the Cheongju M11 plant, and employees temporarily evacuated. M11 is one of the NAND flash production lines at the Cheongju business sites. In January, there was also an incident in which workers came into contact with chemicals during pipe work.
As incidents repeated, SK hynix on the 4th announced the implementation of a "companywide safety system overhaul week" for all employees. The company said it would inspect high-risk tasks and the status of safety management, and carry out activities to identify and improve on-site risk factors, including at partner companies.
Semiconductor plants handle many processes involving gases and chemicals, so even minor incidents can lead to worker safety issues, production instability, and anxiety in the local community. In particular, because the Cheongju business sites house both existing NAND flash production lines and a next-generation DRAM hub including HBM, repeated similar incidents over a short period have prompted calls for precise identification of the causes and measures to prevent recurrence.