The combustion of coal, and hydrocarbons generally, leads to the formation of small but significant amounts of volatile organic compounds (VOCs) and toxic organic micropollutants (TOMPs), as well as methane. These pollutants are generally considered to be formed in the combustion zone, although it is known that some pollutants, such as dioxins, are found in the cooled flue gases. It is shown here that the pollutants undergo changes in concentration during the cooling process. These changes are mapped for the major pollutants from a propane flame and coal devolatilization products.