Interestingly, potassium permanganate and ethylene glycol (anti freeze) are used by the U.S. Forest Service to start fires in remote areas. Plastic spheres about like ping pong balls are filled with potassium permanganate and sealed. The spheres are fed through a machine that injects them with ethylene glycol as they are ejected from an aircraft. After about 20 seconds, the spheres ignite. This provides a cheap and fast way to create long fire lines over difficult terrain.