7 U.S.C. § 138c — Samples

(a) Performance evaluation samples. (1) The Secretary must make sure that performance evaluation samples are sent to any laboratory that has applied for accreditation. (2) The laboratory must analyze those samples and send the results to the Secretary, following the process set out in section 138a of this title. (3) The laboratory must test the samples using methods specifically approved for that purpose, or alternate methods proven to work just as well, as spelled out in regulations under this chapter. (b) Results of testing. (1) The laboratory must submit its test results to the Secretary, on forms the Secretary provides, by whatever date the Secretary sets. (2) The Secretary must evaluate those results and decide whether the laboratory is capable of accurately analyzing chemical residues in agricultural products. (c) Review of accreditation. The Secretary must make sure that laboratories already accredited under this chapter receive new performance evaluation samples to analyze at least twice a year.