40 CFR § 180.547 - Prohexadione calcium; tolerances for residues.

---
identifier: "/us/cfr/t40/s180.547"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 180.547 - Prohexadione calcium; tolerances for residues."
title_number: 40
title_name: "Protection of Environment"
section_number: "180.547"
section_name: "Prohexadione calcium; tolerances for residues."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "E"
subchapter_name: "PESTICIDE PROGRAMS"
part_number: "180"
part_name: "TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "21 U.S.C. 321(q), 346a and 371."
regulatory_source: "36 FR 22540, Nov. 25, 1971, unless otherwise noted."
cfr_part: "180"
---


# 180.547 Prohexadione calcium; tolerances for residues.

(a) *General.* Tolerances are established for residues of the growth regulator, prohexadione calcium, including its metabolites and degradates, in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only prohexadione calcium (calcium 3-oxido-5-oxo-4-propionylcyclohex-3-enecarboxylate)” in or on the following commodities.

| Commodity | Parts permillion |
| --- | --- |
| Cattle, kidney | 0.10 |
| Cattle, meat byproducts, except kidney | 0.05 |
| Cherry, sweet | 0.40 |
| Fruit, pome, group 11 | 3.0 |
| Goat, kidney | 0.10 |
| Goat, meat byproducts, except kidney | 0.05 |
| Grass, forage | 0.10 |
| Grass, hay | 0.10 |
| Grass, seed screenings | 3.5 |
| Grass, straw | 1.2 |
| Hog, kidney | 0.10 |
| Hog, meat byproducts, except kidney | 0.05 |
| Horse, kidney | 0.10 |
| Horse, meat byproducts, except kidney | 0.05 |
| Peanut | 1.0 |
| Peanut, hay | 0.60 |
| Sheep, kidney | 0.10 |
| Sheep, meat byproducts, except kidney | 0.05 |
| Strawberry | 0.30 |
| Watercress | 4.0 |
| Registration is limited to grass grown for seed. |  |

(b) *Section 18 emergency exemptions.* [Reserved]

(c) *Tolerances with regional registrations.* Tolerances with regional registration are established for residues of the plant growth regulator, prohexadione calcium, including its metabolites and degradates, in or on the commodities in table 2 in this paragraph (c). Compliance with the tolerance levels specified in table 2 in this paragraph (c) is to be determined by measuring only prohexadione calcium (calcium 3-oxido-5-oxo-4-propionylcyclohex-3-enecarboxylate) in or on the following commodities.

Table 2 to Paragraph (**c**)

| Commodity | Parts permillion |
| --- | --- |
| Alfalfa, forage | 0.1 |
| Alfalfa, hay | 0.1 |
| Corn, field, forage | 0.1 |
| Corn, field, grain | 0.1 |
| Corn, field, stover | 0.1 |

(d) *Indirect or inadvertent residues.* [Reserved]

[65 FR 25660, May 3, 2000, as amended at 66 FR 29712, June 1, 2001; 76 FR 71464, Nov. 18, 2011; 80 FR 38980, July 8, 2015; 85 FR 8461, Feb. 14, 2020]