Ecotoxicology

The first step is to determine which guidance is relevant. See guidance on risk envelope Chapter 7.5, p 16: 'As the methods and models for the calculation of the exposure are specified in the relevant guidance documents, generally, the relevant guidance documents have to be applied in order to identify the critical GAP.’ It is not always possible to compare uses assessed under different assessment frameworks, for example for applications for extended authorisation. In that case an assessment under a newer assessment framework is required. The assessment framework that applied at the time of submission of the dossier is relevant to the original authorisation, although during the assessment a switch may have been made to a newer guidance, certainly in the case of refined risk assessments. The assessment framework at the time of submission is relevant for new extended authorisations. As stated in the general introduction, extended authorisations with minor uses requested via the NLKUG national procedure are an exception.

Risk envelope parameters

The guidance states that there are various key parameters for each sub-aspect that must be compared. Of particular importance are:

• Dose
• Frequency of use
• Interval of use

Other specific parameters are also important for each sub-aspect, such as:

• relevant target species if birds and mammals are exposed
• drift
• interception values related to the crop
• the attractiveness of a crop to bees, for example.

This is certainly the case with specific parameters or considerations in higher tier assessments (see below). The guidance contains a list of parameters for each component, but these do not always have to be relevant. Depending on the use, additional parameters may also be relevant (for example with mitigating measures). In addition, this guidance is from 2011 and additional parameters may be important for guidances published after this date.

Risk envelope assessment

The guidance states that with higher tier refinements, the risk envelope may become unclear:

'It further should be considered that in case that the relevant trigger values according to Annex VI are breached by the worst-case GAP, a refined risk assessment is required which might take into account more realistic assumptions as specified in the respective guidance documents, or mitigation measures should be proposed. As such refinement steps often are very specific for a crop, region, application timing, etc. it should be carefully considered whether these assessments still cover the lower risk GAPs. If this is not the case the identification of the critical GAP should be started again excluding the GAP addressed by the refined assessment.’

Therefore, in the case of higher-tier refinements, it must always be determined whether these refinements can also be extrapolated to other situations.

It is important that the risk envelope is presented in a transparent and comprehensible manner. Due to the large number of parameters and the complications of changing guidances and higher tier assessments, in a risk envelope analysis it is therefore necessary to clearly discuss each determining parameter of the risk envelope per sub-aspect, preferably in the form of a table. Only in this way can it really be made clear whether a particular use is comparable or less worse-case.

See below the tables used for the risk envelope check.