Carbon Black Safety

What is the current IARC classification for carbon black?

In 1995, and more recently in February 2006, an IARC panel of experts conducted a comprehensive review of carbon black. They concluded that there was “sufficient evidence” of carcinogenicity of carbon black in laboratory animals (based on two inhalation studies in laboratory rats), but that there was “inadequate evidence” of carcinogenicity in humans.  IARC’s overall classification placed carbon black in IARC’s Group 2B as a “possible human carcinogen.”

Does carbon black exposure present any risk of mutagenicity or genotoxicity effects?

No. The term mutagenicity refers to any damage of the DNA; genotoxicity refers to damage to the genes. At times, damage to the gene can be associated with a health abnormality, but in other cases, damage to the gene may result in no abnormality whatsoever. According to current research, there is no evidence that carbon black is a mutagen (i.e., an agent capable of causing mutagenicity) or genotoxic.

Should I be concerned about the trace quantities of PAHs (polyaromatic hydrocarbons) attached to carbon black particles?

Trace quantities of PAHs are present on some carbon blacks as a result of the manufacturing process. These contaminants are tightly bound to the surface of manufactured carbon black (not the case for soot) and can only be removed after vigorous solvent extraction in the laboratory. Additionally, studies have determined that PAHs are not removed from carbon black by human biological processes.  Please refer to the PAH statement in the Resources from ICBA section