The MEECO FireEx is safe and easy to use. At the first sign of a chimney fire simply toss into the firebox and watch the chimney fire stop within minutes. The FireEX is not a flare and works without any pre ignition.? The FireEx has been performance tested using creosote-fuelled chimney fires and will not cause any water damage. Suitable for use on Stoves, Fireplace Inserts and Fireplaces.