---
kind: "section"
citation: "7 U.S.C. § 138c"
title: "7"
title_heading: "Agriculture"
number: "138c"
heading: "Samples"
release: "119-102"
date: "2026-07-12"
url: "https://uscodex.org/usc/7/138c"
units:
  - "Chapter 6A — National Laboratory Accreditation"
---

# §138c. Samples

- (a) **Performance evaluation samples—**
  - (1) **Provided by Secretary—** The [Secretary](/usc/7/138.md?p=5) shall ensure that performance evaluation samples are provided to any [laboratory](/usc/7/138.md?p=3) that has applied for accreditation under this chapter.
  - (2) **Analysis by laboratory—** A [laboratory](/usc/7/138.md?p=3) described in [paragraph (1)](#a-1) shall analyze such performance evaluation samples and submit the results of such analysis to the [Secretary](/usc/7/138.md?p=5), as provided for in [section 138a of this title](/usc/7/138a.md).
  - (3) **Testing methods—** Samples shall be tested by the [laboratory](/usc/7/138.md?p=3) according to methods specifically approved for such purpose by alternate methods of demonstrated adequacy or equivalence, as determined in regulations established under this chapter.
- (b) **Results of testing—**
  - (1) **Submission of results—** The [laboratory](/usc/7/138.md?p=3) shall submit the results of the tests conducted under [subsection (a)](#a) to the [Secretary](/usc/7/138.md?p=5) on forms provided by the [Secretary](/usc/7/138.md?p=5), on or before the date determined by the [Secretary](/usc/7/138.md?p=5).
  - (2) **Evaluation of tests—** The [Secretary](/usc/7/138.md?p=5) shall evaluate the results of such tests achieved by the [laboratory](/usc/7/138.md?p=3) and shall determine whether such [laboratory](/usc/7/138.md?p=3) is capable of undertaking an accurate analysis of chemical residues in [agricultural products](/usc/7/138.md?p=1).
- (c) **Review of accreditation—** The [Secretary](/usc/7/138.md?p=5) shall ensure that performance evaluation samples for analysis are provided to [laboratories](/usc/7/138.md?p=3) accredited under this chapter not less than two times a year.

## Source credit

(Pub. L. 101–624, title XIII, § 1324, Nov. 28, 1990, 104 Stat. 3564.)