When wood burns, it produces heat and a set of byproducts. The two main products are tar and carbon powder, which is popularly known as soot. These have light particles which are released up the chimney as the wood burns. The two types of particles get mixed and form a substance called creosote. Some of the creosote goes out of the chimney, but a large portion of it gets built up on the walls of the flue. As you keep using the fireplace, more creosote gets accumulated and the layer becomes ever thicker. The major problem with creosote is that it is highly inflammable. Its accumulation on the flue walls increases the risk of house fire considerable. In fact, thousands of house fires are caused by creosote build-ups in chimneys every year. Fire is one of the most serious perils which can affect a home. It poses extreme danger to people and property. Another problem with fire starting due to the combustion of creosote is that this substance is toxic and can cause serious irritation to the skin and eyes and possibly mental confusion. With proper chimney cleaning and maintenance, the risk of fire can be reduced to the lowest possible minimum. As a result, lives can be saved and property can be preserved. These are important enough reasons for taking the required measures. You will enjoy the fireplace even more when you know that everyone around is safe.