Assessment of the number of substances being introduced to the global chemical market that may be PMT/vPvM substances requires a clear set of criteria and the ability to scale the application of these criteria to large numbers. The EU Chemicals, Labelling and Packaging (CLP) regulation (EC 1272/2008) criteria for PMT/vPvM substances are displayed in Figure . The mobility (M) aspect (see Figure ) is defined based on the organic-carbon-water partition coefficient (KOC, with units of L/kg) of a chemical which is then log transformed to log KOC values, this is used as a proxy to describe the sorption potential of a chemical to organic carbon. Since experimental log KOC data are rare, it was suggested that the logarithmic octanol-water partition coefficient (log KOW or log P) or the pH-adjusted log DOW (or log D) could be used as a screening parameter for hydrophobicity where high-quality log KOC data are not available . Though the two parameters have some variance, particularly for ionogenic substances, substances with very low log DOW values tend to have very low log KOC values, hence log DOW values were seen as a good alternative screening parameter for mobility. As such they are often used in a complementary fashion (see for more details), where log KOW and log DOW data are used when log KOC data are unavailable. Persistence (P) is defined based on the half-lives of a chemical in different environmental water, sediment and soil systems (see Figure ), and toxicity (T) is defined based on one or a combination of the following: carcinogenicity, mutagenicity, reproductive toxicity, endocrine disruption and specific target organ toxicity after repeated exposure as well as long-term no-observed effect concentration (NOEC) and effect concentration at a given percentage of the population (ECx) shown in Figure .