Is Soot Carcinogenic?
The simple answer is YES.
The following is based on several studies and found in more detail on the following link https://monographs.iarc.fr/ENG/Monographs/vol100F/mono100F-21.pdf
Soot is black particulate matter that is formed as a by-product of combustion or pyrolysis of organic (carbon-containing) materials, such as coal, wood, fuel oil, waste oil, paper, plastics and household refuse. The chemical composition and properties of soots are highly variable and depend on the type of starting material and the conditions of combustion. Soots vary considerably with respect to their relative content of carbon, their particle type, size and shape, and the types of organic and inorganic compounds adsorbed onto the particles. In general, soots have a total carbon content of up to 60%, a high content of inorganic material, and a soluble organic fraction. The latter is extractable with organic solvents and consists largely of PAHs and their derivatives. Inorganic constituents may include oxides, salts, metals, sulfur and nitrogen compounds, water, and other adsorbed liquids and gases.
There is sufficient evidence in humans for the carcinogenicity of soot as found in occupational exposure of chimney sweeps. Soot, as found in occupational exposure of chimney sweeps, causes cancer of the skin (observed in the scrotum), the lung and bladder.
Extracts of soots contain carcinogenic polycyclic aromatic hydrocarbons (PAHs) and are genotoxic.
What to Do
Exposure needs to be kept to a minimum. Only use a professional chimney sweep to sweep your chimney or flue. The above shows the importance of properly sheeting up and sealing a fire or stove, when sweeping, as far as reasonably practicable. I use a SVK30 Sturdy Vac Industrial Vacuum cleaner to prevent any soot seeping into the room when sweeping and for removing soot safely without spillage.
For my own health and safety I also use a Sundstrom SR 100 Half Mask Respirator to protect my lungs from long term damage.
I normally advise my customers to leave the room when the sweep is taking place as an extra safety measure.
Disposal of Soot
If soot from your fire is placed in the your waste bin it is classified as domestic waste, however if I remove it from your home and transport it, it is classified as hazardous waste, which is why I have a lower tier waste carriers licence. Therefore removal of soot from your property may be a chargeable service.