Brief alert issued after US military reports low-risk white phosphorus leak at air base

Fighter jets are parked at Osan Air Base in Pyeongtaek, Gyeonggi Province, May 9. Yonhap

A brief evacuation alert was issued Tuesday in Pyeongtaek, Gyeonggi Province, home to the U.S. Forces Korea, following a report of a minor white phosphorus leak at a U.S. base that officials say posed a low risk.

Police and fire authorities said they received calls from the U.S. military at around 5:07 p.m. reporting the leak of the toxic chemical substance at the K-55 U.S. Osan Air Base in Pyeongtaek, about 60 kilometers south of Seoul.

The Pyeongtaek city government issued the alert notifying the public of the possible white phosphorus leak and advising residents nearby to evacuate to a safe location to prevent skin exposure.

White phosphorus is an extremely toxic substance capable of burning human tissue down to the bone upon contact. Its military use is tightly regulated and discouraged by the international community.

Officials said white phosphorus leaked from two munitions, although the exact amount released remains unconfirmed. No casualties have been reported, they said.

The U.S. military reportedly informed the city that the leaked substance had been roughly 80 percent diluted and that it poses a low risk to public health and the surrounding environment.

Pyeongtaek authorities subsequently lifted the evacuation advisory, about 36 minutes after the initial alert, informing residents that it was safe to return to normal after necessary measures were completed at the U.S. base.

The U.S. military confirmed a "ground mishap" had occurred and cordoned off the area to protect the base and local residents, saying the situation is being addressed swiftly.

"Our emergency response professionals are currently managing an isolated situation on the installation. We are handling this matter with the utmost care and expediency," the U.S. 51st Fighter Wing said in a statement.

The unit added that some reports of a general evacuation of Osan Air Base were incorrect.

The leak report had prompted authorities to send firefighters and related equipment to the scene and coordinate joint responses with the U.S. military, officials said.

Police had set up a cordon with patrol vehicles about 300 to 500 meters from the base as a precaution, and blocked civilian access and detoured traffic.

"The chemical substance, used for cleaning warheads, leaked inside the K-55 munition depot, but the U.S. military informed us that the situation is now under control and poses no danger," a police official said.

"A U.S. military explosive ordnance disposal team and our firefighters responded to the scene, and operations are now largely complete," the official said.