Summary of CLP classification of mixtures

CLP classification of mixtures typically takes place on the basis of test data (physical hazards); or using calculation methods (health and environmental hazards).

There are some exceptions, as a few physical hazards can be estimated by calculation or threshold methods; and health and environmental hazards on a mixture which holds test data can be classified from first principles. However, test data should not be generated for health or environmental hazards of a mixture where this would involve live vertebrate animal testing, unless there is no other alternative, e.g. synergistic effects may significantly increase the toxicity of a mixture.

There are several types of calculation method used:

• classification of individual components compared to a threshold
• classification of total components compared to a threshold
• classification for acute toxicity based on an estimate of total toxicity of components
• classification for acute or chronic aquatic toxicity based on the toxicity of the worst-case components, combined together with other components (the M-factor method)