Abstract: An arrangement is provided for extinguishing burning metal or metal-involved fires by combining an extinguishant with the burning metal to form a resultant material. The resultant material may include an alloy and oxides of the burning material and the extinguishant and in any event forms a coating which is an adherent oxygen barrier. In one form of the invention, the extinguishant comprises mainly elemental copper in commercially available powder form. The extinguishant mixture may also include other material added to improve the deliverability, material flow, electrical resistance, moisture resistance or other characteristics.