Pesticide Registration Toolkit

Bridging an existing residue assessment

Relevant documents
Guidance on bridging of pesticide risk assessments

Principle

In this method, an existing residue assessment, conducted by another – reference – country or body, is “bridged” to the local situation. This is done by reviewing the existing risk assessment from the reference country and a comparing it with the proposed uses and diet in the local situation. On the basis of this comparison, the registrar then evaluates whether the dietary risk in the local situation is similar or lower than in the reference country, and whether the MRL from the reference country can be adopted.
 

Applicability

The bridging procedure described here is a step-wise approach. In the ideal circumstance, where the local situation and the reference country are very similar, the MRL and associated dietary risk assessment, can be accepted relatively simply. If differences exist in diet and/or the Good Agricultural Practice (GAP), only part of the residue assessment of the reference country can be bridged, and some local assessments will need to be done.
 
Complete bridging can be achieved if:
 
  • The residue definition used in the evaluation by the reference country is representative of the intended use(s) in the local situation.
  • The Good Agricultural Practice (GAP) in the local situation is similar or less critical than in the reference country. As a result, the residues on the commodity in the local situation can be expected to be similar or less.
  • The diet used for the risk assessment in the reference country is the same or similar to the diet in the local situation.
 

Data requirements

As a starting point for this procedure, the following information should be available with the registrar:
 
  • The registration dossier for the submitted pesticide, containing at least:
    • The residue definition, including the crop groups on which it was established.
    • The proposed details of use (i.e. Good Agricultural Practice (GAP) table).
  • An detailed existing residue evaluation report of a reference country or of JMPR.

 

Additional data may be required if complete bridging cannot be achieved, including:

  • Residue trials results for the proposed use
 

Assessments

The bridging residue assessment contains the following steps, as outlined according to the left-hand path in the flow chart below:
 
Is the residue definition used in the evaluation by the reference country representative of the intended use(s) in the local situation?
 
If not, bridging stops and a complete local residue assessment has to be conducted.
 
 
Is the Good Agricultural Practice (GAP) in the local situation similar or less critical than in the reference country. As a result, can the residues on the commodity in the local situation be expected to be similar or less?
 
If not, bridging stops and a partial local residue assessment has to be conducted.
 
 
Can the diet used for the risk assessment in the reference country be considered identical or similar to the diet in the local situation? Therefore, are the results of the dietary risk assessment in the reference country applicable to the local situation?
 
If not, bridging stops and a partial local residue assessment has to be conducted.
 
4.  Complete bridging is possible. The existing reside evaluation can be accepted and the associated MRL adopted.
 
These steps are outlined along the left-hand path of the flow chart below. 
 
 
The right-hand side of the chart refers to the complete local residue assessment , which may need to be followed fully or partially, depending on the degree of bridging that is possible.