What are Combustion By-Products (CBPs)?

Combustion by-products are the gases, airborne solid, and liquid particulates that are released when a material undergoes partial combustion. Combustion by-products typically include particulates such as soot, char, ash, metal oxides, and inorganic solids. These solid particulates can settle following a fire event and can result in health hazards and lingering odors.5,6

The residues of the fire, or 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. These materials can be acutely hazardous to humans 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, strokes, upper respiratory system irritation, as well as acute bronchitis and aggravated asthma among children1,2,3, 5.

The following are typical solid particles that are present following a fire event4:

  • Char – Particles that are larger than 1 micron and retain the characteristics of the burned material.
  • Ash – The residue left after complete combustion has occurred.
  • Soot – Fine black particles (mainly carbon) plus residual gas particles resulting from incomplete combustion. These particles typically result from house fires and may be acidic/damaging to metal materials.

Most of these combustion by-product particles are invisible to the naked eye, so testing can be beneficial to determine which materials have been impacted by smoke residue and if remediation/cleaning was effective.

When is testing for Combustion By-Products necessary?<