This fire log is a special log suitable for using in an open fireplace or even a closed fireplace if > 5KW. After ignite the wrapper on both sides the log will burn and will, during burning, let the soot particles in the chimney fall down. The operation of such a fire log helps to prevent a chimney fire. This log will burn for up to 90 minutes. The Fibra-Chimney Sweep has been tested for its function and is, on request, provided with a guarantee certificate. After burning of this fire log you can use your fireplace as desired. We advise you to use one Fibra-Chimney Sweep every sixty fires.