The leaching of bentazone, MCPA and mecoprop to groundwater was assessed using the new proposals for evaluating sorption and degradation studies (Boesten et al. 2015). The three substances are weak acids, showing pH-dependent sorption behaviour in soil. The evaluation led to large corrections for the sorption endpoint, KOM, derived for individual studies. Consequently, the curve describing sorption as a function of soil pH changed, indicating lower sorption over the relevant pH range. None of the available Freundlich exponents passed the reliability check. Using the improved interpretation procedures for sorption and degradation experiments revealed that several usages of the substances did not comply with the threshold limit for leaching when assessed at both Tier 1 and Tier 2 of the decision tree on leaching. The assessments did not reveal shortcomings in the decision tree itself. It is recommended that the improved interpretation procedures for sorption and degradation experiments are used for deriving endpoints for future substance leaching evaluations.