On Tuesday afternoon, U.S. military officials at Osan Air Base (K-55) in Pyeongtaek, South Korea, reported the discovery of residual white phosphorus inside ammunition boxes during a routine inspection. The base implemented safety protocols and completed emergency response procedures.
According to a statement on the Osan Air Base website, base experts identified crystallized white phosphorus residue in ammunition containers. An Explosive Ordnance Disposal (EOD) team was dispatched to assess the situation. The base immediately activated its multi-tiered safety response protocols to secure and safely manage the affected ammunition.
The U.S. Air Force clarified that at 5:08 p.m. (Korean time), they established a 305-meter (1,000-foot) safety perimeter as a precautionary measure. They emphasized that reports of a full evacuation order for the surrounding area were inaccurate.
Officials stated that the base’s emergency response team was actively managing the situation and would resolve it as swiftly and safely as possible.
In a subsequent update, the Air Force confirmed that the situation was fully contained and the safety perimeter had been lifted. They reported that emergency response personnel had successfully mitigated the incident.
Earlier that day, local police and fire departments received reports of a potential chemical leak from a warhead within the base.
Military officials informed local authorities that approximately 80% of the leaked substance had been diluted and currently posed no significant risk.
Pyeongtaek City issued a safety alert, notifying residents of a white phosphorus leak at the K-55 U.S. military base and advising nearby civilians to seek shelter to avoid potential skin exposure.
White phosphorus, an allotrope of phosphorus, can spontaneously ignite in air at temperatures above 30°C (about 86°F). It is commonly used in military applications such as smoke munitions and flares. Skin contact can result in severe burns, while inhalation of its fumes can cause respiratory damage.
A police spokesperson stated that while they continue to monitor the situation, no significant injuries or damage have been reported. As a precaution, they have established a safety cordon and implemented traffic control measures to prepare for any potential developments.