What is the difference between carbon black and soot?
“Carbon Black and Soot: Two Different Substances”, written by Ann Watson and Peter Valberg, and published in the American Industrial Hygiene Association Journal (Volume 62, pages 218-228) in the March/April 2001 edition, summarizes the differences as follows:
Carbon blacks are manufactured under controlled conditions for commercial use primarily in the rubber, painting, and printing industries. In contrast, soots are unwanted by-products from the combustion of carbon-based materials for the generation of energy or heat, or for the disposal of waste. Greater than 97% of carbon black consists of elemental carbon arranged as aciniform particulate, while depending upon the type of soot, the relative amount and type of carbon and the particulate characteristics in soot can vary considerably (< 60% of the total soot particulate mass is carbon).
Other elements and chemical compounds are associated with the particulate carbon in both substances, though soot has much greater percentages of ash and solvent extractable organic compounds.
Additionally, the types of organic compounds found in carbon black are not extractable in biological fluids and are not as biologically potent as those present in soot.