Carbon Black or carbon soot is a material with high economic importance containing pure carbon. Carbon Black is produced through specific combustion processes and the production of this material can be traced back more than one hundred years. It is used in many products including car tyres, printer toner, dyes for leather or textiles and mascara.
As carbon black is used in many products, it is possible for it to be taken into the body through a range of exposure routes. These can include breathing (inhalation), for example from laser printer emissions, or through the skin (dermal uptake) when contact is made with cosmetics and textiles. It is worth noting that swallowing of carbon black (oral uptake) and uptake into the gut is not a common route of uptake for carbon black nanoparticles. Those at greatest risk from coming into contact with this material are the personnel who work in environments producing carbon black nanoparticles. This is a major topic in industry, as several million tons of these particles are produced per year and many studies have been carried out to measure the concentration of carbon black particles in the air and to investigate the possible impact these may have on the workers. When looking at the effects of carbon black on human health the environmental release of carbon particles, such as ultrafine dust from combustion processes or traffic seems to be a bigger issue than manufactured carbon black nanoparticles released from controlled production processes.
Several points need to be taken into consideration when analysing the effects of carbon black in humans, animals or the environment. The purity level of the material is one consideration. Carbon black nanoparticles of high purity cause responses in organisms only at very high concentrations which are considered to be environmentally unrealistic. However, carbon black may contain contaminants either in the carbon material or on the surface of the particles themselves. Fine dust particles (from sources such as industry exhaust gases, car exhausts and cigarette smoking) consist of amorphous carbon and these particles may be loaded with other chemicals. These could enhance any potentially harmful effects on living organisms. Never the less it is possible that pure carbon black nanoparticles may have adverse lung effects when inhaled in large amounts.