IICRC-certified fire restoration services have the ability to assist even in the most extreme situations, according to their organization's mission statement. The first stage in repairing fire damage is a thorough clean-up, and a professional will have the necessary tools, cleaning chemicals, manpower, and, most importantly, the knowledge and experience to complete the work correctly and completely. Plastics and other synthetic materials that are burned by fire leave behind residues of a wide range of hazardous compounds that are difficult to detect. A house fire including wood, one of the most combustible elements on the property, generates smoke that contains methane, carbon monoxide, sulfur dioxide, and heavy metals among other pollutants. Removing acidic ash residue must be done within a few days of its formation.