In cases where there are no EC MRLs, the acceptability of residues may be judged against Codex Maximum Residue Limits. Although Codex limits are not legally binding, they are taken as presumptive standards. These limits give an indication of the likely highest residue that should occur in edible crops. These are based on worldwide uses and the residues trials data to support those uses, at the time of evaluation (date of setting the limits is specified and thus the Maximum Residue Limit applicable up to that year, but will not take into account subsequent approved uses). There are occasions where the MRL that has been set by Codex may not reflect current UK Good Agricultural Practice such as with the Codex MRLs for dithiocarbamates and propamocarb on lettuce. In such circumstances it is possible to exceed the Codex MRL through a UK approved use. This factor needs to be taken into account when assessing results