Regulations last checked for updates: Oct 02, 2026

Title 40 - Protection of Environment last revised: Sep 29, 2026
§ 180.368 - Metolachlor and S-metolachlor; tolerances for residues.

(a) General. (1) Tolerances are established for the combined residues (free and bound) of the herbicide metolachlor, 2-chloro-N-(2- ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide, and its metabolites, determined as the derivatives, 2- [(2-ethyl-6- methylphenyl)amino]-1-propanol and 4-(2-ethyl-6-methylphenyl)-2- hydroxy-5-methyl-3-morpholinone, each expressed as the parent compound in the following raw agricultural commodities:

Table 1 to Paragraph (a)(1)

Commodity Parts per million
Almond, hulls0.3
Animal feed, nongrass, group 181
Cattle, fat0.02
Cattle, kidney0.2
Cattle, liver0.05
Cattle, meat0.02
Cattle, meat byproducts, except kidney and liver0.04
Corn, field, forage6
Corn, field, grain0.1
Corn, field, stover6
Corn, pop, grain0.1
Corn, pop, stover6
Corn, sweet, forage6
Corn, sweet, kernel plus cob with husks removed0.1
Corn, sweet, stover6
Cotton, gin byproducts4
Cotton, undelinted seed0.1
Dillweed0.5
Egg0.02
Goat, fat0.02
Goat, kidney0.2
Goat, liver0.05
Goat, meat0.02
Goat, meat byproducts, except kidney and liver0.04
Grass, forage, fodder and hay, group 17, forage10
Grass, forage, fodder and hay, group 17, hay0.2
Horse, fat0.02
Horse, kidney0.2
Horse, liver0.05
Horse, meat0.02
Horse, meat byproducts, except kidney and liver0.04
Milk0.02
Nut, tree, group 140.1
Okra0.5
Peanut0.2
Peanut, hay20
Peanut, meal0.4
Potato0.2
Poultry, fat0.02
Poultry, meat0.02
Poultry, meat byproducts0.05
Safflower, seed0.1
Sheep, fat0.02
Sheep, kidney0.2
Sheep, liver0.05
Sheep, meat0.02
Sheep, meat byproducts, except kidney and liver0.04
Sorghum, grain, forage1
Sorghum, grain, grain0.3
Sorghum, grain, stover4
Soybean, forage5
Soybean, hay8
Soybean, seed0.2
Tomato0.1
Vegetable, foliage of legume, except soybean, subgroup 7A15
Vegetable, legume, group 60.3

(2) Tolerances are established for residues of S-metolachlor, including its metabolites and degradates, in or on the commodity(s), as defined. Compliance with the tolerance levels specified in the following table below is to be determined by measuring only the sum of free and bound S-metolachlor, S-2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide, its R-enantiomer, and its metabolites, determined as the derivatives, 2-(2-ethyl-6-methylphenyl)amino-1-propanol and 4-(2-ethyl-6-methylphenyl)-2-hydroxy-5-methyl-3-morpholinone, calculated as the stoichiometric equivalent of S-metolachlor, in or on the commodity.

Table 2 to Paragraph (a)(2)

Commodity Parts per million
Beet, sugar, leaves15
Beet, sugar, molasses2
Beet, sugar, roots0.5
Berry, low growing, subgroup 13-07G, except cranberry0.4
Brassica, leafy greens, subgroup 4-16B1.8
Bushberry subgroup 13-07B0.15
Caneberry subgroup 13-07A0.1
Carrot, roots0.4
Cattle, fat0.02
Cattle, kidney0.2
Cattle, liver0.05
Cattle, meat0.02
Cattle, meat byproducts, except kidney and liver0.04
Cilantro, fresh leaves8
Coriander, seed0.13
Corn, field, forage40
Corn, field, grain0.1
Corn, field, stover40
Corn, pop, grain0.1
Corn, pop, stover40
Corn, sweet, forage6
Corn, sweet, kernel plus cob with husks removed0.1
Corn, sweet, stover40
Cotton, gin byproducts4
Cottonseed subgroup 20C0.1
Dill, seed15
Dillweed5
Dillweed, dried leaves9
Egg0.02
Goat, fat0.02
Goat, kidney0.2
Goat, liver0.05
Goat, meat0.02
Goat, meat byproducts, except kidney and liver0.04
Grain, aspirated fractions4
Grass, forage, fodder and hay, group 17, forage10
Grass, forage, fodder and hay, group 17, hay0.2
Horse, fat0.02
Horse, kidney0.2
Horse, liver0.05
Horse, meat0.02
Horse, meat byproducts, except kidney and liver0.04
Kohlrabi0.6
Leaf petiole vegetable subgroup 22B0.1
Lettuce1.5
Milk0.02
Onion, bulb, subgroup 3-07A0.1
Onion, green, subgroup 3-07B2
Peanut0.2
Peanut, hay20
Peanut, meal0.4
Poultry, fat0.02
Poultry, meat0.02
Poultry, meat byproducts0.05
Rosemary, dried leaves2
Rosemary, fresh leaves1.5
Safflower, seed0.1
Sesame, seed0.13
Sheep, fat0.02
Sheep, kidney0.2
Sheep, liver0.05
Sheep, meat0.02
Sheep, meat byproducts, except kidney and liver0.04
Sorghum, grain, forage1
Sorghum, grain, grain0.3
Sorghum, grain, stover4
Sorghum, sweet, stalk4
Soybean, forage5
Soybean, hay8
Soybean, meal1.5
Soybean, seed0.9
Spinach0.5
Stalk and stem vegetable subgroup 22A, except kohlrabi0.1
Stevia, dried leaves15
Sugarcane, cane0.2
Sugarcane, molasses1.5
Sunflower, meal1
Sunflower subgroup 20B1
Swiss chard0.15
Tomato, paste0.3
Vegetable, brassica, head and stem, group 5-160.6
Vegetable, cucurbit, group 90.5
Vegetable, foliage of legume, except soybean, subgroup 7A15
Vegetable, fruiting, group 8-10, except tabasco pepper0.1
Vegetable, leaves of root and tuber, group 2, except sugar beet2
Vegetable, legume, group 60.3
Vegetable, root, except sugar beet, subgroup 1B, except carrot0.3
Vegetable, tuberous and corm, subgroup 1C0.2

(b) Section 18 emergency exemptions. [Reserved]

(c) Tolerances with regional registrations. (1) Tolerances with regional registration as defined in 180.1(l) are established for the combined residues (free and bound) of the herbicide metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] and its metabolites, determined as the derivatives, 2-[2-ethyl-6-methylphenyl)amino]-1-propanol and 4-(2-ethyl-6-methylphenyl)-2-hydroxy-5-methyl-3-morpholinone, each expressed as the parent compound, in or on the following raw agricultural commodities:

Commodity Parts per million
Pepper, nonbell0.50

(2) Tolerances with regional registration are established for residues of S-metolachlor, including its metabolites and degradates, in or on the commodities identified in the following table below. Compliance with the tolerance levels specified in the following table below is to be determined by measuring only the sum of free and bound S-metolachlor, S-2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide, its R-enantiomer, and its metabolites, determined as the derivatives, 2-(2-ethyl-6-methylphenyl)amino-1-propanol and 4-(2-ethyl-6-methylphenyl)-2-hydroxy-5-methyl-3-morpholinone, calculated as the stoichiometric equivalent of S-metolachlor, in or on the commodity.

Commodity Parts per million
Pepper, tabasco0.50

(d) Indirect or inadvertent residues. (1) Tolerances are established for the indirect or inadvertent combined residues (free and bound) of the herbicide metolachlor, 2-chloro-N-(2-ethyl-6- methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide, and its metabolites, determined as the derivatives, 2-[(2-ethyl-6-methylphenyl)amino]-1-propanol and 4-(2-ethyl-6-methylphenyl)-2- hydroxy-5-methyl-3-morpholinone, each expressed as the parent compound in the following raw agricultural commodities:

Commodity Parts per million
Animal feed, nongrass, group 181.0
Barley, grain0.10
Barley, hay0.80
Barley, straw0.80
Buckwheat, grain0.10
Millet, forage0.50
Millet, grain0.10
Millet, hay0.80
Millet, straw0.80
Oat, forage0.50
Oat, grain0.10
Oat, hay0.80
Oat, straw0.80
Rice, grain0.10
Rye, forage0.50
Rye, grain0.10
Rye, straw0.80
Wheat, forage0.50
Wheat, grain0.10
Wheat, hay0.80
Wheat, straw0.80

(2) Tolerances for are established for the indirect or inadvertent residues of S-metolachlor, including its metabolites and degradates, in or on the commodities identified in the following table below. Compliance with the tolerance levels specified in the following table below is to be determined by measuring only the sum of free and bound S-metolachlor, S-2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide, its R-enantiomer, and its metabolites, determined as the derivatives, 2-(2-ethyl-6-methylphenyl)amino-1-propanol and 4-(2-ethyl-6-methylphenyl)-2-hydroxy-5-methyl-3-morpholinone, calculated as the stoichiometric equivalent of S-metolachlor, in or on the commodity.

Commodity Parts per million
Animal feed, nongrass, group 181.0
Barley, grain0.10
Barley, hay0.50
Barley, straw0.50
Buckwheat, grain0.10
Millet, forage0.50
Millet, grain0.10
Millet, hay0.50
Millet, straw0.50
Oat, forage0.50
Oat, grain0.10
Oat, hay0.50
Oat, straw0.50
Rice, grain0.10
Rye, forage0.50
Rye, grain0.10
Rye, straw0.50
Wheat, forage0.50
Wheat, grain0.10
Wheat, hay0.50
Wheat, straw0.50
[73 FR 53740, Sept. 17, 2008, as amended at 74 FR 48412, Sept. 23, 2009; 75 FR 56903, Sept. 17, 2010; 77 FR 48906, Aug. 15, 2012; 77 FR 59127, Sept. 26, 2012; 79 FR 17441, Mar. 28, 2014; 80 FR 38986, July 8, 2015; 83 FR 12274, Mar. 21, 2018; 84 FR 8617, Mar. 11, 2019; 85 FR 40131, July 6, 2020; 91 FR 8104, Feb. 20, 2026]
authority: 21 U.S.C. 321(q), 346a and 371
source: 36 FR 22540, Nov. 25, 1971, unless otherwise noted.
cite as: 40 CFR 180.368