Creosote is the residue left behind in your chimney after burning the fire logs. After frequent use, creosote can form a thick coating inside the chimney firebrick. If left unattended, this accumulated coating is extremely flammable and potentially dangerous, making regular cleaning an important task. Being an indoor air pollutant, many are sensitive to creosote. It is important to burn only clean and well seasoned wood instead of green wood to prevent accumulation of creosote. Avoid burning cardboard or wrapping paper in the fireplace as the sparks may ignite the creosote lining. At all costs, avoid burning treated or painted wood, plywood, particleboard and plastic as highly toxic chemical fumes are released into the air, endangering the health of your family.