U.S. Code of Federal Regulations
Regulations most recently checked for updates: Aug 28, 2025
(a) [Reserved]
(b) Tolerances. The tolerance for quinoxaline-2-carboxylic acid (marker residue) is:
(1) Swine. Liver (target tissue): 30 ppb.
(2) [Reserved]
(c) Related conditions of use. See § 558.115 of this chapter.
