What type of smoke is produced by the burning of toxic material such as rubber tires, wet wood, and plastics?

The production of dark smoke when burning toxic materials such as rubber tires, wet wood, and plastics is a result of incomplete combustion. This incomplete burning process occurs when there is not enough oxygen available to fully oxidize the fuel, leading to the formation of larger particles, soot, and other combustion byproducts.

The coloration of smoke is directly affected by the material being burned and the combustion conditions; dark smoke generally indicates a higher concentration of particulate matter and unburned hydrocarbons. Materials like tires and plastics, which contain various chemicals and compounds, release more notable amounts of particulate matter and carbon when burned improperly, contributing to the dark appearance of the smoke.

In contrast, white smoke typically indicates the presence of water vapor and is seen in the combustion of organic materials in a more complete and less toxic scenario. Gray smoke could be associated with different burning conditions or materials but does not specifically relate to the burning of toxic materials. Colored smoke results from the burning of specific additives or chemicals designed to produce vivid colors, which is not the case when considering the combustion of common toxic waste like rubber or plastics.