Table 24.
Tier 1 study type | Study with active substance (where bees are likely to be exposed) required? | Study with formulation required? | |
---|---|---|---|
Formulation with one active substance | Formulation with more than one active substance | ||
Acute oral | Yes | Yes (a) | Yes |
Acute contact | Yes | Yes (a) | Yes |
Chronic oral toxicity to adults | Yes (c) | Pending on the comparison between acute studies (b) | Yes |
Toxicity to larvae | Yes (c) | Pending on the comparison between acute studies (b) | Yes |
Acute studies with the formulation can be waived when the toxicity can be predicted on the basis of the active substance (e.g. when the formulation consists of the active substance only, or of the active substance in water).
Generally, a study with the active substance will be sufficient; however, if there is an indication from the acute oral study that the formulation is more toxic than the active substance, then the formulation should be tested. In determining whether there is a difference then the endpoints should be expressed in terms of active substance. If the acute formulation endpoint expressed as active substance is more toxic by at least a factor of 3 than the acute endpoint for the active substance, then it can be assumed that the formulation is of greater toxicity and hence chronic and larval testing should also be carried out using the formulation. If the difference is less than a factor of 3, then testing adult chronic and larval toxicity with the active substance is sufficient.
In case of poorly soluble substance, a single study on the formulated product might also be appropriate as surrogate if higher solubility levels are expected with the formulated product under the test conditions.