Brief Evacuation Alert Issued After White Phosphorus Leak at U.S. Osan Air Base

A brief evacuation alert was issued in Pyeongtaek on Tuesday following a minor white phosphorus leak at the K-55 U.S. Osan Air Base, which officials stated posed a low risk to public health and the environment.

Police and fire authorities received reports of the toxic chemical leak between 4:54 p.m. and 5:07 p.m. In response, the Pyeongtaek city government issued an emergency alert advising nearby residents to evacuate to safe locations to prevent skin exposure. The evacuation advisory was lifted approximately 36 minutes after the initial alert once necessary measures were completed.

The U.S. Air Force's 51st Fighter Wing reported that experts discovered residue of white phosphorus crystallization inside a munitions crate during a routine inspection. Military officials stated the leaked substance had been roughly 80 percent diluted and that the situation was fully contained with no injuries to personnel on or off the installation. A police official added that the chemical is used for cleaning warheads.

Local authorities responded by deploying firefighters and coordinating with the U.S. military, including an explosive ordnance disposal team. Police established a cordon between 300 and 500 meters from the base to block civilian access and detour traffic; one report specified that nine vehicles and 31 personnel were deployed to enforce safety measures.

White phosphorus is described as an extremely toxic substance that can ignite spontaneously in the air, produce thick white smoke, and burn human tissue down to the bone upon contact. Its military use is tightly regulated and discouraged by the international community.