Testing of Whole Mixtures

Although testing of the whole mixture as such seems to be the proper way to approach the risk assessment of exposure to that mixture, it will not provide data on combined actions and/or interactions between the individual components of the mixture. Even if the effect of the mixture is compared with the effects of each individual component at comparable concentrations, this will not allow a description of potential synergism, potentiation, or antagonism, and it is even doubtful that deviations from additivity can be concluded. This can only be achieved if dose-response curves are obtained for each of the single compounds. 

Testing of the whole mixture as such has been recommended for mixtures that are not well characterized (Mumtaz et al. 1993), and has successfully been applied for assessing the combined toxicity of simple, defined chemical mixtures where the toxicological properties of the individual components were also investigated, see Section 10.6. 

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