The Chemical Mixture Methodology using Health Code Numbers
The Chemical Mixture Methodology (CMM) provides recommended default emergency exposure guidelines for mixtures of chemicals. The CMM makes extensive use of Health Code Numbers (HCNs) to examine the additive impact that each chemical component in a chemical mixture may have on specific target organs. The CMM is a more realistic predictor of potential human health impacts than can be obtained using the (1) non-conservative method of separately analyzing the consequences of each chemical component or the (2) overly-conservative method of adding the exposures from each chemical together regardless of the human organ targeted by the chemical. The CMM is recommended by SCAPA for potential use in emergency planning hazards assessments (EPHAs), safety analyses, and in emergency response situations. To use the CMM, download the CMM workbook and carefully review the CMM user’s guide.
The latest version of the Chemical Mixture Methodology Workbook (Revision date: 11/20/07) is available for use. A User's Guide for the Chemical Mixture Methodology (Revision Date: 11/26/07) explains how to use this Excel workbook.
We are very interested in your comments, suggestions, or errors found in the Workbook or Users Guide. For further information or to provide feedback, please contact Doug Craig or Rocky Petrocchi.
Additional information on the CMM and HCNs are provided in the CMM and HCN background information webpage.