Petroleum coke, or petcoke, is produced during the oil refining process.
After transportation fuels and other products are manufactured from crude oil, some of the remaining material goes through additional processing called coking.
Coking is the use of heat to crack or break down large hydrocarbon molecules to produce petcoke, a highly stable, solid fuel.
Extensive testing by the Environmental Protection Agency finds petcoke is “a low hazard potential in humans, with no observed carcinogenic, reproductive or development effects.”