Hi there, I'm a new IOSH member but have worked for the Fire Service for 11 years. My thread is quite a specialist one I suppose but I am interested in finding out about any analysis or guidance on the toxicity of fire residue for the contractors/ cleaners during the restoration phase. (Clearly partly combusted products of combustion are extremely hazardous whilst hot gases but what about after the fire phase?) Presumably the level of toxicity depends on the nature of the fire (heat levels, fuel substances, duration, external atmosphere etc.) and its composition must vary dramatically? What level of hazard does this represent to the contractors cleaning it up? If the particles are no longer airbourne do they still pose a significant health hazard? What level of PPE and RPE is therefore necessary as a result? I hope somebody out there can shed some light on this or point me in the right direction. I understand that we should assume the highest level of toxicity is present but has there been any evidence based research into exactly how toxic the soot is during clean-up?

Welcome Hank You could start by locating any relevant BRE research; then move on to the reports of fires such as that have attracted EU-wide interest as a result of their impact [mostly on rivers esp Rhine & Danube] that have fed into the original Seveso Directive. I don't think that the EA have anything of value on this but I would still look. Moving on to your other points:- Toxicity really does have an incredibly variable level; just because it's no longer airborne certainly doesn't mean that it won't be as you start the clean-up. Yes it could present a significant health hazard for respiration and contact. PM me if you need to talk in depth. Frank Hallett

Hi Hank, Just a thought, would each incident be tested on it's own merits by the way of samples going off to a lab? Hopefully, the building owner/occupier would have a list of chemicals (SDS) they use and the locations of these. Normally these would be taken out of the building during the evacuation as part of their protocol. They can then inform the Fire service of said chemicals, so they can make their own decisions about entering the building or not. From this this off chemicals, they would have a good starting point about what they might encounter, burnt or not. I hope my thoughts have been of some use. Pete

The risk here is that the fire itself would change the nature of the chemicals in the building after a blaze. So simply looking at the SDS’s would not necessary tell you much. Some things would simply be burned up in the fire but equally new nasties could be formed during the fire. Which ones and how much would be difficult to tell. Someone, somewhere may have done some research on this and have an idea what you might come across.

An SDS will describe how a substance burns in air by itself in controlled conditions. This is not necessarily what will happen in a fire. In addition, what is the effect of a fire on things that do not have an SDS but have now be transformed by heating eg halogen containing polymers like PVC or other reactions that might create things dioxins and acrylamides. SDS where they exist might be useful but they are only a start.

The range of residues is huge after a fire, and you can only get limited insight into it from SDSs for substances present, if indeed there were any. Modern building materials contain many synthetic polymers and resins. Furniture and fittings are big sources of hazardous by-products. The residues from fires can be a serious issue - I recall reading the case of someone whose fingers had to be amputated after they were burned by HF when clearing out a burned out car. Don't forget that the electrical apparatus will probably be seriously compromised. Soot is a good conductor of electricity and will now be inside your apparatus.

Have you tried contacting the Fire Service College? They have a fire chemistry dept that has lectured on this subject in the past.

Thank you all for an overwhelming response! I'm glad I paid my membership fees now! I will pick over these responses and make some notes and possibly come back to you for some hair splitting but thanks again!!!