Employers who manufacture, distribute or use any of the chemicals newly identified as carcinogens by the U.S. Department of Health and Human Services (HHS) may have to make changes in their hazard communications programs. 

In the National Toxicology Program's (NTP) 12th Report on Carcinogens (RoC) recently released by the HHS -- one of the two cancer lists referenced in OSHA's Hazard Communication Standard (HCS) -- two substances--formaldehyde and aristolochic acids – were added to its list of known human carcinogens, and six substances -- captafol, cobalt-tungsten carbide (in powder or hard metal form), certain inhalable glass wool fibers, o-nitrotoluene, riddelliine (a botanical, not be confused with the drug Ritalin) and styrene -- to its list of chemicals and biological agents that are reasonably anticipated to be human carcinogens. For chemicals like styrene and formaldehyde, which are already listed as carcinogens by the NTP or other organizations, the impact of the listings in the 12th RoC is likely to be minimal because many of the HCS requirements have already been triggered by the previous listings. 

Because chemicals listed in the RoC are considered carcinogens under OSHA's HCS, manufacturers and importers of a chemical or a product containing a chemical listed in the RoC must list the chemical on Material Safety Data Sheets (MSDSs) if it is present at a concentration of 0.1% or greater when the product has not been tested as a whole, and they must include warning information about cancer in the MSDS. Chemicals listed on the RoC that are present at less than 0.1% must also be listed if they could be released from the product in concentrations that could present a health risk to workers. The MSDS must also indicate that the NTP lists the chemical as a carcinogen. 

Employers that use chemicals with new or updated cancer listings in the RoC or products that contain these chemicals should review incoming MSDSs for new information and must train workers about any new chemical or product hazards. Employers must also look at how the chemical or product is used in their workplaces and make sure that the precautions and protective equipment they require are sufficient to protect workers from anticipated exposures. 

More information about employer responsibilities to protect workers from exposure to hazardous substances is available at OSHA's  Safety and Health Topics Page on Carcinogens page.