When product, hazard, exposure and risk mitigation have been compared between the reference and the local situation, an assessment can be made about the risk of the pesticide in the local situation, based on a weight-of-evidence approach. Part of the assessment will be quantitative (e.g. when comparing application rates), but part of it will be semi-quantitative or qualitative (e.g. when comparing types of PPE used). The outcome of the assessment is a judgement whether the risk in the local situation is likely to be lower, similar or higher than in the reference assessment. Table 2 provides a schematic set of outcomes.

In some cases, the magnitude of risk in the reference situation is very low, as the predicted exposure is much lower than the acceptable level (e.g. very low exposure toxicity ratio). For such low-risk products or situations a very precise risk estimate in the local situation may not be needed as it is likely that the risk in the local situation will be acceptable too. Often, it will not be possible to draw a clear conclusion about the risk in the local situation based on bridging. This happens either when the differences in hazard and exposure do not lead to an unequivocal conclusion about risk (see Table 2), or when too many data needed for bridging are unavailable to the registrar. In such cases, risk assessment can be refined using additional local information. Bridging of a risk assessment is generally a semi-quantitative exercise and it is the pesticide registration authority that in the end will have to provide an expert opinion on the risk of the pesticide in the local situation. As this may be ambiguous, it is important that the assessment and the reasoning that led to the conclusion are well documented by the authority so that it can be revisited when new information becomes available.

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