---
kind: "section"
citation: "40 C.F.R. § 180.535"
title: "40"
number: "180.535"
heading: "Fluroxypyr 1-methylheptyl ester; tolerances for residues."
url: "https://uscodex.org/cfr/40/180.535"
---

# §180.535. Fluroxypyr 1-methylheptyl ester; tolerances for residues.

- (a) **General.** Tolerances are established for residues of the herbicide fluroxypyr 1-methylheptyl ester, including its metabolites and degradates, in or on the commodities listed in table 1 to this [paragraph (a)](#a). Compliance with the tolerance levels specified in table 1 to this [paragraph (a)](#a) is to be determined by measuring only the sum of the free and conjugated forms of fluroxypyr 1-methylheptyl ester [1-methylheptyl 2-[(4-amino-3,5-dichloro-6-fluoro-2-pyridinyl)oxy]acetate] and its metabolite fluroxypyr [2-[(4-amino-3,5-dichloro-6-fluoro-2-pyridinyl)oxy]acetic acid] calculated as the stoichiometric equivalent of fluroxypyr, in or on the commodity.
- (b) **Section 18 emergency exemptions.** [Reserved]
- (c) **Tolerances with regional registrations.** [Reserved]
- (d) **Indirect or inadvertent residues.** [Reserved]

## Notes

### Amendments

[63 FR 52169, Sept. 30, 1998, as amended at 64 FR 22799, Apr. 28, 1999; 66 FR 37598, July 19, 2001; 66 FR 47971, Sept. 17, 2001; 67 FR 46884, July 17, 2002; 67 FR 60146, Sept. 25, 2002; 68 FR 75438, Dec. 31, 2003; 69 FR 2074, Jan. 14, 2004; 70 FR 3649, Jan. 26, 2005; 70 FR 7047, Feb. 10, 2005; 71 FR 76204, Dec. 20, 2006; 72 FR 73635, Dec. 28, 2007; 78 FR 3333, Jan. 16, 2013; 83 FR 29706, June 26, 2018; 91 FR 8113, Feb. 20, 2026]

### Authority

Authority: 21 U.S.C. 321(q), 346a and 371.

### Source

Source: 36 FR 22540, Nov. 25, 1971, unless otherwise noted.

### Amendments

[63 FR 52169, Sept. 30, 1998, as amended at 64 FR 22799, Apr. 28, 1999; 66 FR 37598, July 19, 2001; 66 FR 47971, Sept. 17, 2001; 67 FR 46884, July 17, 2002; 67 FR 60146, Sept. 25, 2002; 68 FR 75438, Dec. 31, 2003; 69 FR 2074, Jan. 14, 2004; 70 FR 3649, Jan. 26, 2005; 70 FR 7047, Feb. 10, 2005; 71 FR 76204, Dec. 20, 2006; 72 FR 73635, Dec. 28, 2007; 78 FR 3333, Jan. 16, 2013; 83 FR 29706, June 26, 2018; 91 FR 8113, Feb. 20, 2026]