Chemical Mixtures Working Group (CMWG)
The Chemical Mixtures Working Group was established in 1994 to develop methodology for emergency planning and analysis of exposures to mixtures of materials accidentally released from DOE facilities. Both emergency planning and hazard assessment of DOE facilities and operations require consideration of potential exposures of people and the environment to materials (radiological, chemical, and biological) released to the atmosphere. These potential exposures may be to pure substances or to mixtures.
To address exposures to releases of chemical mixtures, the working group developed the Chemical Mixture Methodology (CMM) to provide recommended default emergency exposure guidelines that are customized for mixtures of chemicals. These are useful in emergency planning hazards assessments, in actual emergency response, as well as in other applications within the DOE complex, such as safety analysis.
The CMM makes extensive use of Health Code Numbers (HCNs). HCNs identify a particular target organ or health effect. They are used in the CMM as a way of “binning” the exposure into separate target organ “bins.” Information on how to use the CMM using HCNs is provided on the CMM using HCN web page. Additional information is provided in the CMM and HCN background information web page.