Carbon black is a material produced by the incomplete combustion of heavy petroleum products such as FCC tar, coal tar, ethylene cracking tar, and a small amount from vegetable oil. Carbon black is a form of amorphous carbon that has a high surface area to volume ratio, although its surface area to volume ratio is low compared to activated carbon. It is dissimilar to soot because of its much higher surface area to volume ratio and significantly less (negligible and non-bioavailable) PAH content. Carbon black is used as a pigment and reinforcement in rubber and plastic produc