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Combustion By-Product

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Combustion By-Product

What are combustion by-products and where do they come from?

Combustion by-products are gases and small particles that are emitted through the incomplete burning of fuels such as oil, gas, kerosene, wood, coal, and propane. The particulate matter components will include drops of condensed soot, char, ash, metal oxides and inorganic solids.

In addition to fire, other sources of combustion by-products include combustion appliances such as:

  • wood heaters and wood stoves
  • furnaces
  • gas stoves
  • fireplaces
  • car exhaust

The type and amount of combustion by-product produced depends on the type of fuel and the combustion appliance, including how well the appliance is designed, built, installed and maintained. Some appliances receive certification depending on how clean burning they are; both the Canadian Standards Association (CSA) and the Environmental Protection Agency (EPA) certify wood stoves and other appliances. Soot, char, and ash are also regarded as indicators for fire combustion residue.

How Eurofins can help

Eurofins offers a comprehensive suite of testing services for the combustion by-product particulates, from simple presence or absence analysis through potential sourcing analysis using advanced chemical and microscopic techniques. At Eurofins, we can accept samples collected on tape lifts, wipes, or micro-vacuuming. Our analytical techniques include but are not limited to:

  • Polarized Light Microscopy (PLM)
  • Epi-Reflected Light Microscopy (RLM)
  • Transmission Electron Microscopy (TEM)

Effects on Health and Environment

These materials can be acutely hazardous to human since they can contain heavy metals, polycyclic aromatic hydrocarbons (PAHs), a cancer-causing substance. The microscopic particles such as soot can easily penetrate deep into the lungs and have been linked to a wide range of serious health effects, including premature death, heart attacks, and strokes, as well as acute bronchitis and aggravated asthma among children.

The effects of combustion by-products on environment include haze and acidification of lakes and rivers.


By analyzing combustion by-products, you can gain useful insight as to cleaning and remediation costs, specifically pertaining to fire investigation/insurance claims.

Fire Investigative Testing

Fire investigative testing is used to determine the presence of fire residues (char, black carbon/soot, and ash). The results are often used to determine the extent of property damage caused by smoke at locations (residential, industrial, or wilderness) to address sourcing, liability, and assist with remediation of contaminants. Testing can be done after a fire event in order to determine what areas might have been impacted, or the testing can be used during or after a cleaning or remediation in order to guide professionals in their remediation efforts.


There are currently no regulatory limits established for the presence of airborne contaminants for the combustion by-products, with an exception for soot which has a limit of 15µg/m3 by the US EPA.

There are also currently no regulatory limits established for the presence of surface contaminants associated with fire loss (smoke or soot residue). Therefore, the results of combustion by-product testing are predominantly used as a “qualitative” measure of assessing areas of potential impact rather than a “quantitative” assessment of the severity of impact.