Division 6.2 Metabolism, distribution and expression of residues

Data on metabolism representative for existing or intended good agricultural practices (GAPs) shall be provided, together with a schematic diagram of the metabolic pathways in plants and animals with a brief explanation of the distribution and chemical reactions involved. These studies shall be conducted with one or more radio-labelled forms of the active substance and, where relevant, stereoisomer forms of the active substance and its metabolites. For plant extracts, a different approach may be taken if adequately justified.

For plants, the objectives of these studies shall be:

1. (a)

   to provide an estimate of total terminal residues in the relevant portion of crops at harvest following treatment as proposed;

2. (b)

   to identify the major components of the total terminal residue;

3. (c)

   to indicate the distribution of residues between relevant crops parts;

4. (d)

   to quantify the major components of the residue and to show the efficiency of extraction procedures for these components;

5. (e)

   to characterise and quantify conjugated and bound residues;

6. (f)

   to indicate the components to be analysed for in residue quantification studies (crop residue studies).

For food producing animals, the objectives of these studies shall be:

1. (a)

   to provide an estimate of total terminal residues in edible animal products;

2. (b)

   to identify the major components of the total terminal residue in edible animal products;

3. (c)

   to indicate the distribution of residues between relevant edible animal products;

4. (d)

   to provide evidence whether or not a residue should be classified as fat soluble;

5. (e)

   to quantify the total residue in certain animal products (milk or eggs) and excreta;

6. (f)

   to quantify the major components of the residue and to show the efficiency of extraction procedures for these components;

7. (g)

   to characterise and quantify conjugated and bound residues;

8. (h)

   to indicate the components to be analysed for in residue quantification studies (livestock feeding studies);

9. (i)

   to generate data from which a decision on the need for feeding studies on food producing animals can be made.

The results of the metabolism study conducted with poultry, normally laying hens, shall be extrapolated to all food producing poultry whereas the results of the metabolism study conducted with ruminants, normally lactating goats and, where necessary, with pigs, shall be extrapolated to all food producing mammals.

Metabolites not found in the ADME studies or that cannot be explained as intermediates, but identified in metabolism/transformation studies (plant, food producing animals, processing and rotational crops) shall be considered relevant for the consumer risk assessment, unless it can be demonstrated by scientific evidence (such as structure-activity relationship, toxicological bridging studies) that, also in view of their concentration, they cause no potential risks to the consumer.