In a ruling that could slow EPA's approval of
nanomaterial-based pesticides, the Ninth Circuit on May 30
invalidated EPA's conditional approval of NSPW-L30SS, formerly
known as Nanosilva. Natural Resources Defense Council
(NRDC) v. EPA (9th Cir., May 30, 2017). The
Court found that EPA's determination that use of
nanosilver-based pesticides would result in lower overall silver
emissions into the environment, and therefore was in the public
interest, was faulty because it was based on two assumptions that
lacked support—that current users of pesticides containing
conventional silver would switch to the new pesticide, and that the
new pesticide would not be used in new products. The Ninth
Circuit noted that a 2009 EPA Scientific Advisory Panel had found
that the hazard profile of nanosilver "may differ from other
forms of silver." NRDC, one of the plaintiffs in the
case, hailed the decision as closing a loophole that has allowed
premature approval into the market of
