John Balbus, M.D., M.P.H., is Chief Health Scientist.

EPA’s recently released draft Nanotechnology Research Strategy (NRS) proposes a tiered testing system to evaluate human toxicity of nanomaterials.  It puts in vitro tests, or those done in test tubes and petri dishes as opposed to living animals, front and center.  EPA says the results of the first, in vitro tier will be used for guidance on “what health endpoints to monitor” and the second, in vivo tier will then help “identify those in vitro assays that correlate with in vivo nanomaterial toxicity or health effects.”

Wait a second.  If the in vivo testing is necessary in order to figure out what the in vitro testing results really mean, how can the agency use the in vitro testing results to figure out what health endpoints to monitor?  This cart and horse confusion is a serious matter. Read More »