Posted By Ian Bruce Miriam, Not an expert on soot or other by-products that may be present from a fire, but remember to think about the potential for asbestos containing materials. Surface coverings such as "Artex" contain asbestos that may have the potential to release air bourne fibres following damage. I suggest you check any existing asbestos registers or level 2 survey results and include this info into any risk assessments prepared prior to clean up operations. Just as an aside, if you've had a fire in a premises, think about the buildings structural integrity following the fire - get a structural engineer to give it the once over before letting anyone in to perform any work.