Here there were serious reservations about the accuracy of this testing scheme. It was noted that exposure

through four months of age is not ‘lifetime exposure’. Effects that don’t appear until middle and/or old age would likely be missed. Such delayed effects are one of the hallmarks of endocrine disrupters. Additionally, multiparous females are never tested. Effects related to multiple pregnancies (in the mother or in the offspring) would find more also be missed by this testing scheme. The greatest needs for test development were identified as 1) low doses and 2) subpopulations. Regarding testing of low doses, it was noted that different endpoints have different sensitivities. An assay used in low dose testing might show no effect, while another assay, testing a different endpoint, might very well show an effect at the same

dose. The group agreed that any in vitro effects of low doses must be followed by in vivo testing. An unanswered question closed this area, ‘what are the regulatory consequences of low dose effects? Testing of specific subpopulations (of perhaps differing sensitivities) was another area where the group suggested test development. Specific populations would include but not be limited to i) those exposed to other known or suspected endocrine disrupters (e.g., concurrent exposure ABT-199 order to specific pharmaceuticals), Animal models used for routine in vivo testing were discussed and it was agreed that while the rat is viewed as the standard,

depending on the endpoint this may not be appropriate. The rat, for example, is not the best model of human birth; at parturition, the seldom-used guinea pig has a hormonal profile much more like that of the human. The group agreed that while an increase in animal studies is not desirable, there is a need for test development in other than the typical species so that, depending Interleukin-3 receptor on the endpoint, the model that is most like the human can be used. It was agreed that this development was needed, but not to put this on the list of ‘greatest needs’. Testing of mixtures was discussed but agreement could not be reached on whether or not to place this on the list of ‘greatest needs for further test development’. It was agreed by the group that testing of mixtures is an important issue, but a tremendous issue and extremely hard to tackle. It was suggested that company testing of formulations might be a good starting place. It was also noted that the potential risk of exposure to mixtures does not require different tests but rather use of existing (and suggested) tests but applied mixtures rather than single compounds.