In your letter you ask that OSHA consider a regulatory clarification concerning commercial carbon black. The report is well organized to summarize the previous human and animal studies that have been conducted for carbon black. In your January 12 letter you asked the Agency to distinguish between two different substances- harmful soots and chars and commercial carbon black. After a thorough review of the available health information, OSHA agrees that there is a difference between commercially produced carbon black within the United States and substances identified as soots and chars and not manufactured by the same process. Soots and chars may have could exposed workers to a carcinogenic hazard.
Airborne exposure present a similar hazard.
Your request to modify the entry in and a significant amount of resources. Carbon black is not on OSHA's list of priorities to conduct rulemaking. Therefore, OSHA will not at this time undertake an effort to modify the X list. Agency acknowledgment of theses differences should clarify any misunderstanding the health effects of the material may have with soots and chars and OSHA's hazard communication standard. Finally, your letter mentions that carbon black should be classified as a nuisance dust and that exposure to it does not produce serious health effects.