The RT25 Test (OCSPP 850.3030) consists of applying a pesticide, already known to have acute contact toxicity in laboratory studies, to foliage and then measuring the amount of time that the pesticide product remains toxic to bees. While this test is considered to be a useful measurement by beekeepers and growers, USEPA risk assessors do not have a high degree of confidence in the consistency of the results of this test across different testing laboratories due to a lack of standardization of the USEPA OCSPP test method.

To address concerns with this test, the PRTF, with visibility to the USEPA and in coordination with several testing laboratories are evaluating ways to help standardize the EPA test protocol. A “ring test” using the improved standard protocol will then be conducted and the results evaluated.