Beveridge & Diamond
Related Practices
Related Practices

Ninth Circuit Upholds Tolerances For Four Pesticides and Questions Tolerances For Three Others

Beveridge & Diamond, P.C., September 25, 2008

On September 19, the Ninth Circuit Court of Appeals upheld EPA’s choice of a safety factor and thus EPA’s tolerance decisions for four pesticides.1   Northwest Coalition for Alternatives to Pesticides v. EPA, No. 05-07255 (9th Cir. Sept. 19, 2008).  However, in the same opinion, the Court held that EPA had failed to justify its decision to deviate from a tenfold child safety factor for tolerances for three pesticides and remanded the Agency’s decisions to EPA for further proceedings consistent with the Court’s opinion.2   The case is important, both in terms of the Court’s rulings on the specific requirements of the tolerance law as well as the Court’s views on the extent to which EPA, and other federal agencies, must explain the basis for administrative decisions. 

Northwest Coalition involved a challenge to EPA’s Final Order denying a number of petitions asserting that EPA had failed to adequately address children’s health when it established tolerances for seven pesticides.  Under the Food Quality Protection Act of 1996 (FQPA), Congress directed EPA to use a tenfold margin of safety to account for exposure and toxicity to infants and children when setting pesticide tolerances.  21 U.S.C. §346a(b)(2)(C).  However, Congress also gave EPA the authority to deviate from this tenfold safety margin if “on the basis of reliable data, such margin will be safe for infants and children.”  Id.  EPA used a 3x safety factor for four of the pesticides, and did not apply a children’s safety factor for the remaining three.  Slip Op. at  13,245. 

The Ninth Circuit rejected Petitioners’ arguments that computer modeling does not constitute “reliable data.”  Id. at 13,249-52.  According to the Court, EPA had adequately explained why computer modeling does yield reliable data and Petitioners had presented no evidence to suggest that EPA’s explanation was “faulty or suspect.”  Id. at 13,252.  The Ninth Circuit also rejected Petitioners’ claims that EPA should have waited to promulgate the tolerances until after it had the results of certain studies on neurotoxicity that the Agency had earlier requested.  Id. at 13,252-54.  The Court held that EPA was entitled to change its mind regarding whether the studies were necessary to its tolerance decisions.  Id. at 13,254. 

As to three of the pesticides, however, the Court held that EPA’s Order was too “vague” to determine whether its decision to reduce the safety factor was supported by reliable data.  Id. at 13,254.  EPA had indicated that the data did not demonstrate increased sensitivity for children or developing fetuses, but the Court found that EPA did not provide reasoning for the specific safety factor that it ultimately selected.  Id. at 13,255.  Without an explanation from EPA, the Court held that it was unable to conclude whether EPA’s tolerance decisions for these three pesticides were supported by reliable data and remanded the decisions to EPA.  Id. at 13,258.  Judge Ikuta dissented from this final portion of the opinion, reasoning that Petitioners had failed to raise this argument before the Agency.  Id. at 13,258-66.  Judge Ikuta further asserted that the record did provide an adequate basis to conclude that EPA’s selection of safety factors was not arbitrary.  Id. at 13,267-70.

This case is important both because it is one of the very few cases interpreting how EPA is to implement FQPA’s 10x children’s safety factor, and because it adds to the body of case law on the important issue of the extent to which agencies, and EPA in particular, must explain the basis for their decisions.  

If you would like further information or to discuss the implications of this decision in more detail, please contact Kathy Szmuszkovicz at 202-789-6037 or or Bethany French at 202-789-6042 or

1 The four pesticides are fenhexamid, halosulfuron-methyl, isoxadifen-ethyl, and zeta-cypermethrin. 

2 The three pesticides are acetamiprid, mepiquat, and pymetrozine.