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Veterinary Manual

Find information on animal health topics, written for the veterinary professional.

Overview of Herbicide Poisoning

Also of Interest

Overview of Herbicide Poisoning

By P. K. Gupta, PhD, Post Doc (USA), PGDCA, MSc VM & AH BVSc, FNA VSc, FASc, AW, FST, FAEB, FACVT (USA), Gold Medalist, Editor-in-Chief, Toxicology International

Herbicides are used routinely to control noxious plants. Most of these chemicals, particularly the more recently developed synthetic organic herbicides, are quite selective for specific plants and have low toxicity for mammals; other, less-selective compounds (eg, sodium arsenite, arsenic trioxide, sodium chlorate, ammonium sulfamate, borax, and many others) were formerly used on a large scale and are more toxic to animals.

Vegetation treated with herbicides at proper rates normally will not be hazardous to animals, including people. Particularly after the herbicides have dried on the vegetation, only small amounts can be dislodged. When herbicide applications have been excessive, damage to lawns, crops, or other foliage is often evident.

The residue potential for most of these agents is low. However, runoff from agricultural applications and entrance into drinking water cannot be excluded. The possibility of residues should be explored if significant exposure of food-producing animals occurs. The time recommended before treated vegetation is grazed or used as animal feed is available for a number of products.

Most health problems in animals result from exposure to excessive quantities of herbicides because of improper or careless use or disposal of containers. When herbicides are used properly, poisoning problems in veterinary practice are rare. With few exceptions, it is only when animals gain direct access to the product that acute poisoning occurs. Acute signs usually will not lead to a diagnosis, although acute GI signs are frequent. All common differential diagnoses should be excluded in animals showing signs of a sudden onset of disease or sudden death. The case history is critical. Sickness after feeding, spraying of pastures or crops adjacent to pastures, a change in housing, or direct exposure may lead to a tentative diagnosis of herbicide poisoning. Generally, the nature of exposure is hard to identify because of storage of herbicides in mis- or unlabeled containers. Unidentified spillage of liquid from containers or powder from torn or damaged bags near a feed source, or visual confusion with a dietary ingredient or supplement, may cause the exposure. Once a putative chemical source has been identified, an animal poison control center should be contacted for information on treatments, laboratory tests, and likely outcome.

Chronic disease caused by herbicides is even more difficult to diagnose. It may include a history of herbicide use in proximity to the animals or animal feed or water source, or a gradual change in the animals’ performance or behavior over a period of weeks, months, or even years. Occasionally, it involves manufacture or storage of herbicides nearby. Samples of possible sources (ie, contaminated feed and water) for residue analysis, as well as tissues from exposed animals taken at necropsy, are essential. Months or even years may be required to successfully identify a problem of chronic exposure.

To recognize whether an animal has been exposed to herbicides or accidental poisoning, standardized analytical procedures for diagnostic investigation of biologic materials have become established and are subsumed under the term “biomonitoring.” Accurate biomonitoring is an important tool to evaluate human or animal exposure to such herbicides by measuring the levels of these chemicals, their metabolites, or altered biologic structures or functions in biologic materials such as urine, blood or blood components, exhaled air, hair or nails, and tissues. The use of urine is advantageous because of ready availability. As such, urine has been used for biomonitoring of several herbicides, including 2,4-D, 2,4,5-T, MCPA (2-methyl-4-chlorophenoxyacetic acid), atrazine, diuron, alachlor, metolachlor, paraquat, diquat, imazapyr, imazapic, imazethapyr, imazamox, imazaquin, and imazamethabenz-methyl herbicides, with the objective to assess exposure and health risk to exposed animals.

If poisoning is suspected, the first step in management is to halt further exposure. Animals should be separated from any possible source before attempting to stabilize and support them. If there are life-threatening signs, efforts to stabilize animals by general mitigation methods should be started. Specific antidotal treatments, when available, may help to confirm the diagnosis. As time permits, a more detailed history and investigation should be completed. The owner should be made aware of the need for full disclosure of facts to successfully determine the source of poisoning, eg, unapproved use or failure to properly store a chemical.

Toxicity and Management of Poisoning

There are >200 active ingredients used as herbicides; however, some of them are believed to be obsolete or no longer in use. Of these, several have been evaluated for their toxic potential and are discussed below. More specific information is available on the label and from the manufacturer, cooperative extension service, or poison control center. Selected information on herbicides, such as the acute oral toxic dose (LD50) in rats, the amount an animal can be exposed to without being affected (no adverse effect level), the likelihood of problems caused by dermal contact in rabbits (dermal LD50, eye and skin irritation), deleterious effects on avian species, and toxicity to fish in water, is included for some commonly used herbicides (see Table: Herbicide Poisoning). Comparative toxic doses (TD) and lethal doses (LD) of selected herbicides in domesticated species, such as monkeys, cattle, sheep, pigs, cats, dogs, and chickens, is also summarized (see Table: Oral Toxic Doses (TD) and Lethal Doses (LD) of Herbicides in Domestic Species). The information is only a guideline, because the toxicity of herbicides may be altered by the presence of other ingredients (eg, impurities, surfactants, stabilizers, emulsifiers) present in the compound. With a few exceptions, most of the newly developed chemicals have a low order of toxicity to mammals. However, some herbicides, such as atrazine, buturon, butiphos, chloridazon, chlorpropham, cynazine, 2,4-D and 2,4,5-T alone or in combination, dichlorprop, dinoseb, dinoterb, linuron, mecoprop, monolinuron, MCPA (2-methyl-4-chlorophenoxyacetic acid), prometryn, propachlor, nitrofen, silvex, TCDD (a common contaminant during manufacturing process of some herbicides such as 2,4-D and 2,4,5-T), and tridiphane, are known to have adverse effects on development of embryos and reproduction abnormalities in experimental animals. A list of such chemicals is summarized in Herbicides with Potential to Cause Developmental Toxicity in Experimental Animals.

Herbicide Poisoning

Compound

Acute Oral LD50—Rat

NOAELa (oral)

Acute Dermal LD50

Avian Toxicity/NOAECb

Toxicity to Fish in Water

Skin and Eye Irritation

Acetochlor

2,148–2,950 mg/kg

Dog, 1 yr 12 mg/kg/day

Rabbit 4,166 mg/kg

LC50 5 day

Bobwhite quail and Mallard duck 5,620 mg/kg

LC50 96 hr

Rainbow trout 0.45 mg/L

Skin–mild

Eye–mild

Acifluorfen

1,300 mg/kg (F)

Rat, 2 yr 180 ppm

Rabbit >2,000 mg/kg

LC50 8 day

Mallard duck >10,000 mg/kg

LC50 96 hr

Rainbow trout 31 mg/L

Skin–moderate

Eye–severe

Acrolein

29 mg/kg

Rat, 13 wk 150 mg/L in drinking water

Rabbit 231 mg/kg

LD50 (oral)

Bobwhite quail 19 mg/kg

Mallard duck 9.1 mg/kg

LC50 24 hr

Bluegill and Rainbow trout 0.024 mg/L

Skin–severe

Eye–severe

Alachlor

930–1,200 mg/kg

Dog, 90 days <200 mg/kg/day

Rabbit 13,300 mg/kg

Skin–mild

Ametryn

1,009–1,405 mg/kg

Rat reproduction, 50 ppm

Rabbit 2,020 mg/kg

LD50 (oral)

Birds >2,250 mg/kg

LC50 5 day

Birds >5,620 ppm

Skin–irritation

Guinea pig–dermal sensitization

Eye–mild

α-Metolachlor

2,675–2,952 mg/kg

Dog, 90 days 0.0125 mg/kg/day

Rat 2,020 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck >10,000 ppm

LC50 96 hr

Bluegill and Rainbow trout 3.9–10 ppm

Skin–slight

Eye–mild

Atrazine

2,000–3,080 mg/kg

Dog, 1 yr 150 ppm

Rat, 2 yr 10 ppm

Rabbit 7,500 mg/kg

LC50 8 day

Mallard duck >10,000 ppm in diet

LC50 96 hr

Rainbow trout 8.8 mg/L

Skin–slight

Amitrole

4,080 mg/kg (M)

Rat, 13 wk 2 mg/kg/day

Rat >5,000 mg/kg

LD50

Mallard duck 2,000 mg/kg

Skin–mild

Eye–mild

Ammonium sulfamate

3,900 mg/kg

Rat, 105 days 10,000 mg/kg/day

LD50

Bobwhite quail 3,000 mg/kg

LC50 48 hr

Crucian carp 1,000–2,000 mg/L

Skin–none

Bensulfron methyl

>5,000 mg/kg

Rat, dog, 2 yr 750 ppm in diet

Rat >2,000 mg/kg

LC50 96 hr

Bluegill and Rainbow trout >150 ppm

Skin–none

Eye–serious

Bensulidec

271–770 mg/kg

Dog, 90 days 12.5 mg/kg/day

Rabbit 3,950 mg/kg

LD50

Bobwhite quail 3 wk 50 mg/kg, poor hatchability

LC50 96 hr

Bluegill 1.4 mg/L

Rainbow trout 0.7 mg/L

Eye–none

Bentazon

1,100 mg/kg (cat 500 mg/kg)

Rat, 90 days 3.5 mg/kg/day

Dog, 90 days 7.5 mg/kg/day

Rat >2,500 mg/kg

LD50

Japanese quail 720 mg/kg

Mallard duck 2,000 mg/kg

LC50 96 hr

Bluegill 616 mg/L

Rainbow trout 1,060 mg/L

Slight irritant

Bispyribac sodium

Rat, 2 yr

1.1 mg/kg/day (M)

1.4 mg/kg/day (F)

LC50

Bobwhite quail and Mallard duck >5,620 ppm

LC50 96 hr

Bluegill and Rainbow trout >100 ppm

Skin–minor

Eye–minor

Borax

2,000–6,000 mg/kg

Bromacil

5,200 mg/kg

Rat, dog, 2 yr 250 mg/kg/day

Rabbit >5,000 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck >10,000 mg/kg

LC50 48 hr

Bluegill 71 mg/L

Rainbow trout 56 mg/L

Skin–irritating

Eye–irritating

Bromoxynil

190–779 mg/kg

Rat, 90 days 50 mg/kg/day

Rabbit >2,000 mg/kg

Acute LD50

Bobwhite quail 100 mg/kg

Mallard duck 200 mg/kg

LC50 96 hr

Rainbow trout 0.05 mg/L

Skin–none

Eye–none

Butachlorc

2,000–3,300 mg/kg

Rabbits maternal and fetal effects, 50 mg/kg/day

Rat >13.3 g/kg

Skin–none

Eye–moderate

Guinea pig–dermal sensitization

Butylatec

>5,431 mg/kg (M) 4,659 mg/kg (F)

Rat, 2 yr 20 mg/kg/day

Dog, 1 yr 25 mg/kg/day

Rabbit >4,640 mg/kg

LC50 8 day

Bobwhite quail 40,000 mg/kg

Mallard duck 46,400 ppm in diet

LC50 96 hr

Bluegill 6.9 mg/L

Rainbow trout 4.2 mg/L

Skin–moderate

Eye–mild

Carfentrazone ethyl

>5,000 mg/kg

Rat, 2 yr

9 mg/kg/day (M)

3 mg/kg/day (F)

Rat >5,000 mg/kg

LC50

Bobwhite quail and Mallard duck >5,620 ppm

LC50 96 hr

Bluegill 2 ppm

Rainbow trout 16 ppm

Skin–none to slight

Eye–minimum

Chloramben

5,620 mg/kg

Rabbit >3,160 mg/kg

LC50 8 day

Mallard duck >4,640 mg/kg

Not toxic to fish

Skin–mild

Eye–mild

Chlorotoluron

>10,000 mg/kg

LC50 96 hr

Rainbow trout >100 mg/L

Chlorpropham

4,100–7,000 mg/kg

Rat, dog, 2 yr 100–350 mg/kg/day

LD50 8 day

Mallard duck >2,000 mg/kg

LC50 48 hr

Bluegill 6.3–6.8 mg/L

Rainbow trout 3–6 mg/L

Skin–moderate

Eye–moderate

Chlorsulfuron

5,545 mg/kg (M)

6,293 mg/kg (F)

Rat, 2 yr 100 ppm in diet

Rabbit >3,400 mg/kg

LC50 8 day

Mallard duck >5,000 mg/kg

LC50 96 hr

Rainbow trout >250 mg/L

Skin–none

Eye–mild

Chlorthal dimethyl

3,000–12,000 mg/kg

Rat, 2 yr <50 mg/kg/day

Rabbit >2,000 mg/kg

LD50 young

Bobwhite quail 5,500 mg/kg

Not toxic to fish

Skin–none

Eye–mild

Clethodim

1,630 mg/kg (M)

1,360 mg/kg (F)

Dog, 1 yr >1 mg/kg/day

Rabbit >5,000 mg/kg

LC50 8 day

Bobwhite quail 4,270 ppm

Mallard duck 3,978 ppm in diet

LC50

Bluegill 13 ppm

Rainbow trout 18 ppm

Skin–none

Eye–moderate

Clodinafop propargyl

1,392 mg/kg (M)

2,271 mg/kg (F)

Dog, 90 days

0.346 mg/kg/day (M)

1.89 mg/kg/day (F)

Rabbit >2,000 mg/kg

LC50

Birds >5,000 ppm

LC50

Freshwater fish 0.3 ppm

Skin–none

Eye–slight to severe

Clomazone

2,077 mg/kg (M)

1,369 mg/kg (F)

Dog, 1 yr <2.5 mg/kg/day

Rabbit >2,000 mg/kg

LD50 8 day

Bobwhite quail and Mallard duck 5,620 ppm in diet

LC50 96 hr

Bluegill 34 mg/L

Rainbow trout 19 mg/L

Skin–mild

Eye–moderate

Clopyralid

>4,300 mg/kg

Rat, 2 yr 50 mg/kg/day

Rabbit >2,000 mg/kg

LC50

Bobwhite quail and Mallard duck >4,640 ppm in diet

LC50 96 hr

Bluegill 125 mg/L

Rainbow trout 103.5 mg/L

Skin–mild

Eye–severe

Cloransulam-methyl

>5,000 mg/kg

Dog, 1 yr 10 mg/kg/day

Rabbit >2,000 mg/kg

LC50 5 day

Bobwhite quail and Mallard duck >5,620 ppm

LC50 96 hr

Bluegill >154 ppm

Rainbow trout >86 ppm

Skin–none

Eye–slight

Copper chelate

498 mg/kg

Rabbit >2,000 mg/kg

LC50 8 day

Mallard duck >1,000 ppm in diet

LC50 96 hr

Bluegill 1.2–7.5 mg/L

Rainbow trout <0.2–4 mg/L

Skin–slight

Eye–moderate

Copper sulfate

470 mg/kg

Rabbit >8,000 mg/kg

LD50 (oral)

Pheasant 1,000 ppm in diet (estimated)

LC50 96 hr

Bluegill 4.4–7.3 mg/L

Rainbow trout 0.135 mg/L

Skin–moderate

Eye–severe

Cyanazined

182–334 mg/kg

Dog, 2 yr <225 mg/kg/day

Rabbit >2,000 mg/kg

LD50

Bobwhite quail 400 mg/kg

Mallard duck >2,000 mg/kg

LC50 96 hr

Bluegill 23 mg/L

Rainbow trout 9 mg/L

Skin–none

Eye–mild

Cycloate

2,000–3,190 mg/kg

Dog, 240 mg/kg/day

Rabbit >4,640 mg/kg

LC50 7 day

Bobwhite quail >56,000 mg/kg

LC50 96 hr

Rainbow trout 5.6 mg/L

Skin–none

Eye–none

Cyhalofopbutyl

>5,000 mg/kg

Dog, 46.7 mg/kg/day (M)

45.9 mg/kg/day (F)

Rat >5,000 mg/kg

LC50 96 hr

Bluegill >99.2 mg/L

Rainbow trout >1.65 mg/L

Skin–none

Eye–minimal

Dalapon

6,600–9,330 mg/kg

LC50 96 hr

Fish 210–340 mg/L

Di-allated

340–460 mg/kg

LC50 96 hr

Fish 8.2 mg/L

2,4-D

370–700 mg/kg

Rat, 2 yr 50 mg/kg/day

Rabbit >2,000 mg/kg

LC50 8 day

Mallard duck >4,640 mg/kg

LC50 96 hr

Bluegill >300 mg/L

Rainbow trout 800 mg/L

Skin–none

Eye–moderate

2,4-D dimethyl-amine

949–4,650 mg/kg

Dog, 1 yr 1 mg/kg/day

Rabbit >2,000 mg/kg

LC50 8 day

Mallard duck >5,600 ppm

LC50 96 hr

Bluegill 524 mg/L

Rainbow trout 250 mg/L

Skin–minimal

Eye–severe

2,4-D isooctyl ester

500–700 mg/kg

Dog, 1 yr 1 mg/kg/day

Rabbit >2,000 mg/kg

As for 2,4-D (above)

Skin–none

Eye–severe

Dazomet

551–646 mg/kg (M)

335–562 mg/kg (F)

Rat, 2 yr 1.6 mg/kg/day

Rabbit >2,000 mg/kg

LD50

Bobwhite quail 415 ppm in diet

LC50

Rainbow trout 2.4–16.2 mg/L

Skin–mild

Eye–severe

Dicamba

1,707 mg/kg

Rat, 2 yr 125 mg/kg/day

Dog, 2 yr 50 mg/kg day

Rabbit >2,000 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck >4,600 mg/kg

LC50 96 hr

Bluegill and Rainbow trout >1,000 mg/L

Skin–moderate

Eye–extreme

Dichlobenil

>3,160 mg/kg

Rat, 2 yr >20 ppm in diet

Pig, 6 mo >50 ppm in diet

Rabbit >1,350 mg/kg

LC50 8 day

Mallard duck >5,200 ppm in diet

LC50 96 hr

Bluegill and Rainbow trout 7 mg/L

Skin–none

Eye–mild to moderate

Dichlorprop or 2,4-DP

700 mg/kg (M)

500 mg/kg (F)

Rat, 4 mg/kg

Mouse 1,400 mg/kg

LC50

Upland birds, waterfowl >10,000 ppm in diet

LC50

Bluegill 1.1 mg/L

Rainbow trout 100–200 mg/L

Skin–none

Eye–none

Diclosulam

>5,000 mg/kg

Rat, 0.05 mg/kg

Rabbit >2,000 mg/kg

LC50

Most sensitive aquatic species 10-100 mg/L

Skin–moderate

Eye–moderate

Difenzoquat (methylsulfate)

617 mg/kg (M)

373 mg/kg (F)

Dog, 1 yr 20 mg/kg/day

Rabbit >2,000 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck 4,640 ppm in diet

LC50 96 hr

Bluegill 696 mg/L

Rainbow trout 711 mg/L

Skin–mild

Eye–mild

Diflufenzopyr

1,600 to >5,000 mg/kg

Dog, 1 yr

28 mg/kg/day (M)

26 mg/kg/day (F)

Rabbit >5,000 mg/kg

LC50

Mallard duck >5,620 ppm

LC50

Bluegill 135 ppm

Rainbow trout 106 ppm

Skin–very slight

Eye–mild to slight

Dimethenamid

429–1,293 mg/kg

Dog, 1 yr 50–250 ppm in diet

Rabbit >2,000 mg/kg

LC50

Bobwhite quail and Mallard duck >5,620 ppm in diet

LC50

Bluegill 6.4 mg/L

Rainbow trout 2.6 mg/L

Skin–mild

Eye–moderate

Dinoterb

25 mg/kg

LC50

Partridges 3–5 ppm in diet

Toxic to fish

Diquat

231–440 mg/kg

Rat reproduction, 1 mg/kg/day

Rabbit >400 mg/kg

LC50

Partridges 270–300 ppm in diet

LC50

Fish 80–210 mg/L

Skin–none

Eye–mild

Dithiopyr

>5,000 mg/kg

Dog, 1 yr <0.5 mg/kg/day

Rabbit >5,000 mg/kg

LC50

Bobwhite quail and Mallard duck >5,260 ppm in diet

LC50

Bluegill 0.7 mg/L

Rainbow trout 0.5 mg/L

Skin–slight

Eye–moderate

Diuron

3,400 mg/kg

Dog, 2 yr 25 mg/kg

Rat >2,000 mg/kg

LC50

Bobwhite quail 1,730 ppm

Mallard duck >5,000 ppm in diet

LC50

Bluegill 7.4 mg/L

Rainbow trout 4.3 mg/L

Skin–none

Eye–mild

DNOC

25–85 mg/kg

Rat, 2 yr 0.59 mg/kg/day

Rat 600–2,000 mg/kg

Rabbit 1,000 mg/kg

LD50

Japanese quail 10–25 mg/kg

LC50

Fish 0.2–13 mg/L

Skin–erythema and edema

Eyes–corrosive

Guinea pig–dermal sensitization

EPTC (s-ethyldipropylthiocarbamate)

1,630 mg/kg

Dog, 90 days 20 mg/kg

Rabbit 2,750–5,000 mg/kg

LC50 7 day

Bobwhite quail 20,000 ppm in diet

LC50

Bluegill 27 mg/L

Rainbow trout 19 mg/L

Skin–mild

Eye–severe

Ethalfluralin

Rat >5,000 mg/kg (dog, cat >200 mg/kg)

Rat, mouse, 90 days 68 mg/kg

Rabbit >2,000 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck >5,000 ppm

LC50

Bluegill 0.03–0.1 mg/L

Rainbow trout 0.037–0.136 mg/L

Skin–slight to moderate

Eye–slight

Ethephon

1,600–4,229 mg/kg

Rat, 2 yr 375 mg/kg/day

Mouse, 78 wk 4.5 mg/kg/day

Rabbit >5,000 mg/kg

LC50 8 day

Mallard duck >10,000 ppm

LC50 96 hr

Bluegill 222–300 mg/L

Rainbow trout 254–350 mg/L

Skin–corrosive

Eye–corrosive

Fenoxapropd

2,357 mg/kg (M)

2,500 mg/kg (F)

Dog, 2 yr 0.375 mg/kg/day

Rabbit >1,000 mg/kg

LD50 Japanese quail >5,000 mg/kg

LC50

Bluegill 3.3 mg/L

Rainbow trout 3.4 mg/L

Skin–slight

Eye–serious nonreversible corneal opacity

Fenoxaprop-ethyld

4,430 mg/kg

Dog, 2 yr 0.9 mg/kg/day

Rat >5,000 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck 5,620 ppm

LC50

Bluegill 0.31 mg/L

Rainbow trout 0.46 mg/L

Skin–slight

Eye–moderate

Flamprop-methyl

1,210 mg/kg

Dog, 2 yr 10 mg/kg/day

Rat >294 mg/kg

LD50

Bobwhite quail 4,640 mg/kg

Mallard duck >1,000 mg/kg

LC50 96 hr

Rainbow trout 4.7 mg/L

Skin–none

Eye–none

Florasulam

>6,000 mg/kg

Dog, 1 yr 5 mg/kg/day

Rabbit >2,000 mg/kg

LD50 14 day

Japanese quail 175 mg/kg

LC50 96 hr

Rainbow trout >100 mg/L

Skin–none

Eye–none

Fluazifop-p-butyl

3,680–4,096 mg/kg (M)

2,451–2,721 mg/kg (F)e

Rat, 90 days >10 mg/kg/day

Rabbit >2,400 mg/kg

LD50 5 day

Bobwhite quail >4,659 ppm

Mallard duck >4,321 ppm

LC50 96 hr

Bluegill 0.5 mg/L

Rainbow trout 1.4 mg/L

Skin–slight

Eye–mild

Flucarbazone-sodium

>5,000 mg/kg

Dog, 1 yr 35.9 mg/kg/day

Rat >5,000 mg/kg

NOAEC (reproduction)

Mallard duck 233 mg/kg/day

NOAEL (chronic)

Rainbow trout 2.75 mg/L

Skin–none

Eye–minimal

Flufenacet

1,617 mg/kg (M)

589 mg/kg (F)

Dog, 1 yr 1.29 mg/kg/day

Rat >2,000 mg/kg

LC50 5 day

Bobwhite quail >5,317 ppm

Mallard duck >4,970 ppm

LC50

Bluegill 2.26–2.4 ppm

Rainbow trout 3.49–5.84 ppm

Skin–none

Eye–minimal

Flumetsulam

>5,000 mg/kg

Rat >2,000 mg/kg

LC50

Mallard duck >5,620 ppm

LC50

Bluegill >300 ppm

Rainbow trout >293 ppm

Skin–none

Eye–slight

Flumiclorac

3,200 to >5,000 mg/kg

Dog, 1 yr 100 mg/kg/day

Rat >2,000 mg/kg

LC50

Mallard duck >5,620 ppm

LC50 96 hr

Bluegill 17.4 mg/L

Rainbow trout 1.1 mg/L

Skin–severe

Eye–moderate

Fluometuron

>8,000 mg/kg

Rat, 103 wk 125 mg/kg/day

Rat >2 g/kg

Rabbit 10 g/kg

LC50 96 hr

Bluegill 96 mg/L

Rainbow trout 47 mg/L

Crucian carp 17 mg/L

Fluroxypyr

>5,000 mg/kg

Dog, 1 yr 150 mg/kg/day

Rat >2,000 mg/kg

LC50 5 day

Mallard duck >5,000 ppm

LC50 96 hr

Bluegill 14.3 mg/L

Rainbow trout 13.4–100 mg/L

Skin–none

Eye–slight

Fluthiacet

>5,000 mg/kg

Dog, 1 yr

57.6 mg/kg/day (M)

30.3 mg/kg/day (F)

Rat >2,000 mg/kg

LC50 5 day

Bobwhite quail and Mallard duck >5,620 ppm

LC5096 hr

Bluegill 140 mcg/L

Rainbow trout 43 mcg/L

Skin–none

Eye–minimal

Foramsulfuron

>3,881 mg/kg

Rat, 2 yr

849 mg/kg/day (M)

1,135 mg/kg/day (F)

Rat >5,000 mg/kg

LC50

Bobwhite quail and Mallard duck >5,000 ppm

Skin–moderate

Eye–mild

Fosamine ammonium

24,000 mg/kg

Rat, 90 days 1,000 mg/kg

Rabbit >1,683 mg/kg

LD50

Mallard duck >10,000 ppm in diet

LC50

Bluegill 670 mg/L

Rainbow trout 1,000 mg/L

Skin–none

Eye–moderate to severe

Glufosinate (ammonium salt)

1,510–2,030 mg/kg

Dog, 1 yr 5 mg/kg/day

Rat >1,390 mg/kg

LC50 5 day

Japanese quail >5,000 mg/kg

LC50 96 hr

Bluegill 56–75 mg/L

Rainbow trout >26.7 mg/L

Skin–slight

Eye–moderate to severe

Glyphosate

4,230–5,600 mg/kg

Dog, 2 yr >500 mg/kg/day

Rabbit >5,000 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck 4,500 ppm in diet

LC50 96 hr

Bluegill 120 mg/L

Rainbow trout 86 mg/L

Skin–none

Eye–slight to moderate

Halosulfuron

1,287 mg/kg

Dog, 13 wk 10 mg/kg/day

Rat >5,000 mg/kg

LC50 5 day

Bobwhite quail and Mallard duck >5,620 ppm

LC50 96 hr

Bluegill >118 mg/L

Rainbow trout >131 mg/L

Skin–slight

Eye–slight

Hexazinone

1,690 mg/kg

Rat, 2 yr 250 mg/kg in diet

Rabbit >5,278 mg/kg

LC50 5–8 day

Bobwhite quail and Mallard duck >10,000 ppm in diet

LC50 96 hr

Bluegill 370–420 mg/L

Rainbow trout 320–420 mg/L

Skin–none

Eye–severe but reversible

Imazamethabenzmethyl

>5,000 mg/kg

Dog, 1 yr 1,000 ppm

Rabbit >2,000 mg/kg

Skin–none

Eye–slight

Imazaquin

>5,000 mg/kg

Dog, 1 yr 1,000 ppm

Rabbit >2,000 mg/kg

Skin–slight

Imazamox

>5,000 mg/kg

Dog, 1 yr 40,000 ppm

Rat >4,000 mg/kg

LC50

Mallard duck >5,672 ppm

LC50 96 hr

Bluegill >119 ppm

Rainbow trout >122 ppm

Skin–none

Eye–none

Imazapic

>5,000 mg/kg

Dog, 1 yr 5,000 ppm

Rabbit >2,000 mg/kg

Skin–slight

Eye–moderate

Imazapyr

>5,000 mg/kg

Dog, 1 yr feeding 1,000 ppm

Rat 300 mg/kg/day (teratology)

Rabbit >2,000 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck >5,000 ppm in diet

LC50 96 hr

Bluegill and Rainbow trout >100 mg/L

Skin–mild

Eye–more severe

Imazethapyr

>5,000 mg/kg

Dog, 1 yr 25 mg/kg/day

Rabbit >2,000 mg/kg

LD50

Bobwhite quail and Mallard duck >2,150 ppm in diet

LC50 96 hr

Bluegill 420 mg/L

Rainbow trout 340 mg/L

Skin–mild

Eye–irritation reversible

Isoproturon

1,800–2,400 mg/kg

Dog, 90 days

Rat, 2 yr 3 mg/kg/day

Rat >3.2 g/kg

LC50 96 hr

Crucian carp 193 mg/L

Rainbow trout 240 mg/L

Skin–none

Eye–none

Isoxaflutole

>5,000 mg/kg

Dog, 1 yr 1,200 ppm

Rat >2,000 mg/kg

LC50 5 day

Bobwhite quail and Mallard duck >4,255 ppm

LC50 96 hr

Bluegill >4.5 mg/L

Rainbow trout >1.7 mg/L

Skin–minimal

Eye–minimal

Linuron

1,200–4,000 mg/kg

Dog, 2 yr 6.25 mg/kg/day (observed anemia)

Rabbit >5,000 mg/kg

LC50 5–8 day

Japanese quail >5,000 ppm

Mallard duck 3,083 ppm in diet

LC50 96 hr

Bluegill and Rainbow trout 16 mg/L

Skin–mild

Eye–moderate

Maleic hydrazide

>5,000 mg/kg (acid)

>6,950 mg/kg (Na+ salt)

>3,900 mg/kg (K+ salt)

Dog, 1 yr 25 mg/kg

Rabbit >20,000 mg/kg

LD50

Bobwhite quail and Mallard duck >10,000 mg/kg

LC50 96 hr

Bluegill 1,608 mg/L

Rainbow trout 1,435 mg/L

Skin–slight

Eye–severe

MCPA

700–1,160 mg/kg

Rat, 7 mo 100 mg/kg/day (lowers wt gain)

Rabbit 3,400–4,800 mg/kg

LD50

Bobwhite quail 377 mg/kg

LC50 96 hr

Bluegill and Rainbow trout 90 mg/L

Skin–slight

Eye–moderate

MCPB

4,700 mg/kg

Rat, 6 mo 1.6 mg/kg/day

Rat >2,000 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck >5,000 ppm in diet

LC50 96 hr

Bluegill 14 mg/L

Rainbow trout 4.3 mg/L

Skin–moderate

Eye–moderate

Mecoprop

930–1,210 mg/kg

Rat, 90 days 3.8 mg/kg/day

Dog, 90 days 15 mg/kg/day

Rabbit 900 mg/kg

LC50

Bobwhite quail and Mallard duck 5,000–5,500 ppm in diet

LC50 96 hr

Bluegill >100 mg/L

Rainbow trout 124 mg/L

Skin–slight

Eye–intense

Mesotrione

>5,050 mg/kg

Rat >5,050 mg/kg

LD50

Bobwhite quail >2,000 mg/kg

Mallard duck >5,200 mg/kg

LC50 96 hr

Bluegill and Rainbow trout >120 mg/L

Skin–slight

Eye–moderate

Metam (sodium and isothiocyanate)

1,800 mg/kg (M)

1,700 mg/kg (F)

97 mg/kg (isothiocyanate)

Rat, 65 days (inhalation, in inspired air) 6 hr/day for 5 days/wk at 0.045 mg/L

Rabbit 10,000 mg/kg

LC50

Bobwhite quail >10,000

Mallard duck >5,000 ppm in diet

LC50 96 hr

Bluegill 0.047 mg/L

Rainbow trout 0.029 mg/L

Skin–corrosive

Eye–corrosive

Methyl bromide

Acute LC50 (inhalation) 4.5 mg/L air

Safe threshold for people 0.065 mg/L air

Acute toxicity

Bluegill 11 mg/L

Skin–severe

Eye–severe

Methyl isothiocyanate

82 mg/kg (M)

Dog, 2 yr 10 mg/L in drinking water

Rabbit 202 mg/kg (F)

145 mg/kg (M)

LC50 5 day

Mallard duck 10,936 mg/kg

LC50 96 hr

Bluegill 0.13 mg/L

Rainbow trout 0.37 mg/L

Skin–corrosive

Eye–severe

Metobromuron

2,450–2,500 mg/kg

Rat, 2 yr 250 mg/kg/day

Dog, 100 mg/kg/day

Rabbit >2,000 mg/kg

LC50 8 day

Bobwhite quail >20,000 ppm

Mallard duck >4,640 ppm in diet

LC50 96 hr

Bluegill 4 mg/L

Rainbow trout 3 mg/L

Skin–moderate

Eye–moderate

Metolachlorc

800–2,780 mg/kg

Rat, 90 days 1,000 mg/kg

Dog, 90 days 500 mg/kg

Rabbit >5,000 mg/kg

Rat >10 g/kg

LC50 5 day

Bobwhite quail and Mallard duck >10,000 ppm in diet

LC50 96 hr

Bluegill 15 mg/L

Rainbow trout 3 mg/L

Skin–none

Eye–none

Metosulam

>5,000 mg/kg

Dog, 1 yr 10 mg/kg/day

Rabbit >2,000 mg/kg

Skin–none

Eye–slight

Metribuzin

1,090–2,300 mg/kg

Rat, 2 yr 5 mg/kg

Dog, 2 yr 2.5 mg/kg

Rat, rabbit >20,000 mg/kg

LC50

Bobwhite quail and Mallard duck >4,000 ppm in diet

LC50 96 hr

Bluegill 80 mg/L

Rainbow trout 64–76 mg/L

Skin–none

Eye–none

Napropamide

>5,000 mg/kg

Dog, 13 wk <100 mg/kg

Rabbit >4,640 mg/kg

LC50 5 day

Bobwhite quail >5,600 ppm

Mallard duck 7,200 ppm in diet

LC50 96 hr

Bluegill 20–30 mg/L

Rainbow trout 9–16 mg/L

Skin–none

Eye–none

Naptalam

>5,000 mg/kg

1,770 mg/kg (Na+ salt)

Rat, dog, 90 days 1,000 mg/kg (Na+ salt)

Rabbit >20,000 mg/kg

LC50 8 day

Bobwhite quail 5,600 ppm

Mallard duck >10,000 ppm in diet

LC50 96 hr

Bluegill 354 mg/L

Rainbow trout 76 mg/L

Skin–mild

Eye–moderate

Nicosulfuron

Mouse >5,000 mg/kg

Dog, 1 yr >5,000 ppm in diet (M)

Rat, rabbit >2,000 mg/kg

LC50

Bobwhite quail and Mallard duck >5,620 ppm in diet

LC50 96 hr

Bluegill and Rainbow trout >1,000 mg/L

Skin–none

Eye–moderate

Oxadiazon

>5,000 mg/kg

Rat, dog, 2 yr 100 mg/kg

Rabbit >2,000 mg/kg

LC50

Bobwhite quail and Mallard duck >5,620 ppm in diet

LC50 96 hr

Bluegill 12.5 mg/L

Rainbow trout 2 mg/L

Skin–moderate

Eye–mild

Oxyfluorfen

Rat, dog >5,000 mg/kg

Rat, 2 yr 2 mg/kg

Dog, 2.5 mg/kg

Rabbit >5,000 mg/kg

LC50

Bobwhite quail >5,000

Mallard duck >4,000 ppm in diet

LC50 96 hr

Bluegill 0.2 mg/L

Rainbow trout 0.41 mg/L

Skin–none

Eye–moderate

Paraquat (dichloride)

150–283 mg/kg

Rat, 2 yr 1.25 mg/kg

Dog, 1 yr 0.45 mg/kg

Rat >2,000 mg/kg (finished product)

LC50 5 day

Bobwhite quail 981 ppm

Mallard duck 4,048 ppm in diet

LC50 96 hr

Rainbow trout 26 mg/L

Skin–slight

Eye–moderate

Pebulate

1,120 mg/kg

Rat, 2 yr 15 ppm in diet (eye lesions)

Rabbit 4,640 mg/kg

LC50

Bobwhite quail and Mallard duck >2,400 ppm in diet

LC50 96 hr

Bluegill and Rainbow trout 7.4 mg/L

Skin–slight

Eye–mild

Pendimethalin

1,050 to >5,000 mg/kg

Dog, 2 yr 12.5 mg/kg/day

Rabbit >5,000 mg/kg

LC50 8 day

Bobwhite quail 3,149 ppm

Mallard duck 10,900 ppm in diet

LC50 96 hr

Bluegill 0.199 mg/L

Rainbow trout 0.138 mg/L

Skin–none

Eye–mild

Phenmedipham

8,000 mg/kg

Dog, 2 yr >1,000 ppm in diet

Rat >2,000 mg/kg

Rabbit >10,000 mg/kg

LC50 4 day

Bobwhite quail >2,480 ppm in diet

LC50 96 hr Bluegill 760 mg/L

LC50 21 day Rainbow trout >210 mg/L

Skin–moderate

Eye–severe

Picloram

5,000–8,200 mg/kg

Rat, 2 yr 150 mg/kg/day

Rabbit >4,000 mg/kg

LD50 8 day

Bobwhite quail >2,500

Mallard duck >5,000 mg/kg

LC50 96 hr

Bluegill 14.5 mg/L

Rainbow trout 19.3 mg/L

Skin–mild

Eye–moderate

Prometryn

3,750–5,235 mg/kg

Dog, 90 days <200 ppm in diet

Rabbit >2,000 mg/kg

LC50 5–7 day

Bobwhite quail and Mallard duck >10,000 ppm in diet

LC50 96 hr

Bluegill 10 mg/kg

Rainbow trout 2.5–2.9 mg/L

Skin–none

Eye–slight

Propanil

1,080 to >2,500 mg/kg

Dog, 2 yr <85 ppm in diet

Rabbit >5,000 mg/kg

LC50 8 day

Bobwhite quail 2,861 ppm

Mallard duck 5,627 ppm in diet

LC50 96 hr

Bluegill 2.3 mg/L

Rainbow trout 4.6 mg/L

Skin–moderate

Eye–serious

Propoxycarbazone

>5,000 mg/kg

Dog, 1 yr

258 mg/kg (M)

55.7 mg/kg (F)

Rat >5,000 mg/kg

Skin–slight

Eye–minimal

Propyzamide

5,620–8,350 mg/kg

Dog, 2 yr >7.5 ppm in diet

Rabbit 3,160 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck >10,000 ppm in diet

LC50 96 hr

Bluegill 100 mg/L

Rainbow trout 72 mg/L

Skin–slight

Eye–moderate

Pyrazon

3,030–3,600 mg/kg

Dog, 2 yr 1,500 ppm in diet

Rat >2,000 mg/kg

LC50

Bluegill 40 mg/L

Skin–slight

Eye–slight

Pyridate

1,285–1,412 mg/kg

Dog, 1 yr 30 mg/kg/day

Rabbit >2,000 mg/kg

LC50 8 day

Bobwhite quail >5,000 ppm in diet

LC50 96 hr

Rainbow trout >1.2 mg/L

Skin–none

Eye–slight

Pyrithiobac-sodium

4,000 mg/kg

Rat (longterm), 59 mg/kg

Rat >2,000 mg/kg

LC50

Bobwhite quail and Mallard duck >6,300 ppm

LC50 96 hr

Bluegill 5.8 mg/L

Rainbow trout 8.2 mg/L

Skin–mild

Eye–moderate

Quinclorac

3,060 mg/kg (M)

2,190 mg/kg (F)

Dog, 1 yr

142 mg/kg/day (M)

140 mg/kg/day (F)

Rat >2,000 mg/kg

LD50

Bobwhite quail and Mallard duck >5,000 mg/kg

LC50 96 hr

Bluegill and Rainbow trout >100 mg/L

Skin–irritating

Eye–moderate

Quizalofop-p-ethyl

1,210–1,670 mg/kg (M)

1,182–1,480 mg/kg (F)

Dog, 1 yr <10 mg/kg/day

Rat, mouse, rabbit >10,000 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck >5,000 ppm in diet

LC50 96 hr

Bluegill 0.46–2.8 mg/L

Rainbow trout 10.7 mg/L

Skin–none

Eye–slight

Rimsulfuron

>5,000 mg/kg

Dog, 1 yr 50 ppm in diet

Rabbit >2,000 mg/kg

LC50 8 day

Bobwhite quail >5,620 ppm

Mallard duck >2,510 ppm in diet

LC50 96 hr

Bluegill 100 mg/L

Rainbow trout 32 mg/L

Skin–mild

Eye–mild

Sethoxydim

3,200 mg/kg (M)

2,676 mg/kg (F)

Dog, 1 yr

>8.86 mg/kg (M)

>9.41 mg/kg (F)

Rat, mouse >5,000 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck >5,600 ppm in diet

LC50 96 hr

Bluegill and Rainbow trout >1,000 mg/L

Skin–none

Eye–moderate

Siduron

>7,500 mg/kg

Rat, 2 yr 500 ppm in diet

Rabbit >5,500 mg/kg

LC50

Bobwhite quail and Mallard duck >10,000 mg/kg

LC50 48 hr

Crucian carp 18 mg/L

Skin–slight

Eye–slight

Simazine

>5,000 mg/kg

Rat, 2 yr >5 mg/kg/day

Rabbit >10,200 mg/kg

LC50 8 day

Bobwhite quail >5,260 ppm

Mallard duck 10,000 ppm in diet

LC50 96 hr

Bluegill and Rainbow trout >100 mg/L

Skin–none

Eye–none

Sodium chlorate

1,200–7,000 mg/kg

Rabbit 500 mg/kg

LC50 48 hr

Fish 10,000 mg/L

Skin–moderate

Eye–moderate

Sulfentrazone

2,416–3,297 mg/kg

Rat, 10 mg/kg/day (oral developmental studies)

Rat >5,000 mg/kg

LD50

Bobwhite quail and Mallard duck >5,620 ppm

LC50 96 hr

Bluegill 93.8 mg/L

Rainbow trout >130 mg/L

Skin–mild

Eye–moderate

Sulfosulfuron

>5,000 mg/kg

Mouse, 90 days 7,000 mg/kg of diet

Rat >5,000 mg/kg

LD50

Bobwhite quail and Mallard duck 5,620 ppm

LC50 96 hr

Rainbow trout >97 mg/L

Skin–slight

Eye–slight

Tebuthiuron

644 mg/kg

Dog, 1 yr >25 mg/kg/day

Rabbit >200 mg/kg

LD50

Bobwhite quail and Mallard duck >2,500 mg/kg

LC50 96 hr

Bluegill 112 mg/L

Rainbow trout 144 mg/L

Skin–slight

Eye–slight

Thiazopyr

>5,000 mg/kg

Dog, 1 yr 0.8 mg/kg/day

Rat >5,000 mg/kg

LD50

Bobwhite quail and Mallard duck 5,328 mg/kg

LC50

Bluegill and Rainbow trout 3.5 mg/L

Skin–slight

Eye–slight

Thifensulfuron-methyl

>5,000 mg/kg

Rat, 2 yr 25 ppm in diet

Rabbit >2,000 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck >5,620 mg/kg

LC50 96 hr

Bluegill and Rainbow trout 100 mg/L

Skin–none

Eye–moderate

Tralkoxydim

1,258 mg/kg (M)

934 mg/kg (F)

Rat (teratogen), 30 mg/kg

Rat >2,000 mg/kg

LD50

Mallard duck >3,020 mg/kg

LC50 96 hr

Bluegill >6.1 mg/L

Rainbow trout >7.2 mg/L

Skin–mild

Eye–mild

Triallate

800–2,165 mg/kg

Dog, 2 yr 15 mg/kg/day (highest tested)

Rabbit 8,200 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck >5,000 mg/kg

LC50 96 hr

Bluegill 1.3 mg/L

Rainbow trout 1.2 mg/L

Skin–moderate

Eye–slight

Triasulfuron

>5,000 mg/kg

Dog, 1 yr 129 mg/kg/day

Rat >2,000 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck >5,000 ppm

LC50 96 hr

Bluegill and Rainbow trout >100 ppm

Skin–none

Eye–none

Tribenuron-methyl

>5,000 mg/kg

Dog, 1 yr 875 ppm in diet

Rabbit >2,000 mg/kg

LC50

Bobwhite quail and Mallard duck >5,620 ppm

LC50 96 hr

Bluegill 760 mg/L

Rainbow trout 730 mg/L

Skin–none

Eye–mild to moderate

Trichloracetic acid

3,200–5,000 mg/kg

Rat >2,000 mg/kg

LD50

Chicken 4,280 mg/kg

Not toxic to fish

Skin–severe

Eye–severe

Triclopyr

630–729 mg/kg

Rat, 2 yr 3 mg/kg/day

Rabbit >2,000 mg/kg

LC50 8 day

Bobwhite quail 2,935 ppm

Mallard duck >5,401 ppm in diet

LC50 96 hr

Bluegill 148 mg/L

Rainbow trout 117 mg/L

Skin–none

Eye–slight

Trifluralin

>5,000 mg/kg

Dog, 2 yr 18.75 mg/kg/day

Rabbit >2,000 mg/kg

LC50 8 day

Bobwhite quail and Mallard duck >5,000 ppm in diet

LC50 96 hr

Bluegill 0.05–0.07 mg/L

Rainbow trout 0.02–0.06 mg/L

Skin–none

Eye–moderate

Vernolate

1,200–1,900 mg/kg

Dog, 90 days >38 mg/kg/day

Rabbit >1,955 mg/kg

LC50 7 day

Bobwhite quail 12,000 ppm in diet

LC50 96 hr

Bluegill 8.4 mg/L

Rainbow trout 9.6 mg/L

Skin–none

Eye–none

a NOAEL = No observable adverse effect level, daily dosage or ppm concentration in the diet

b NOAEC = No observable adverse effect concentration

c Liquid

d Obsolete or no active registration

e Technical grade chemical

Oral Toxic Doses (TD) and Lethal Doses (LD) of Herbicides in Domestic Species

Compound

TD/LD

Species

Dosage (mg/kg)

Phenoxy acid derivatives

Phenoxy acid and its sodium salt

LD50

Chickens

547

Dogs

100–800

LD

Pigs

500

Hens

380–765

TD

Pigs

100

Calves

200

Butyl glycol ester

TD

Cattle

250 for 3 days

Sheep

250 for 2 days

Amine salts

TD

Cattle

250 for 10 days

Sheep

250 for 10 days or

Sheep

500 for 7 days

Bipyridyl compounds or quaternary ammonium

Paraquat

LD50

Dogs

25–50

Cats

35

Monkeys

50–70

Cattle

35–50

Chickens

110–360

LD

Sheep

8–10

Pigs

75

Diquat

LD50

Dogs

100–200

Cats

35–50

Cattle

20–40

Chickens

200–400

Ureas and thioureas

Diuron

TD

Cattle

100 for 10 days

Sheep

250 or 100 for 2 days

Chickens

50 for 10 days

Linuron

TD

Dogs

100–200

Cats

35–50

Cattle

20–40

Chickens

200–400

Tebuthiuron

LD50

Cats

>200

TD

Cats

200

LD50

Dogs

>500

TD

Dogs

50/day for 3 moa

Chickens, quail, or ducks

No deaths were reported at a dosage of 500 mg/kg body wt.

Protoporphyrinogen oxidase inhibitors

Metribuzin

LD50

Cats

>500

Anilide, acetamides, or amide compounds

Propanil

LD50

Dogs

1,217

Propyzamide

LD50

Dogs

>10,000

Dinitrophenolic compounds

DNOC

LD50

Hens

26

Dogs

50

Pigs

50

Goats

100

TD

Cattle

2–50

Sheep

20–50

LD

Sheep

25 for 5 days

Dinoseb

LD50

Hens

26

TD

Cattle

25 for 8 days

Sheep

25 for 10 days

Dinitroaniline

Trifluralin

LD50

Dogs

>2,000

Bromacil

TD

Cattle

250

Chickens

500 for 10 days

Sheep

50 for 10 days or 250 for 8 days

Carbamates and thiocarbamate compounds

Asulam

LD50

Rabbits

>2,000

Chickens

>2,000

Dogs

>5,000

Di-allate

LD50

Dogs

510

TD

Chickens

150 for 10 days or 250 for 7 days

Cattle

25 for 5 days or 50 for 3 days

Sheep

25 for 5 days or 50 for 3 days

Phenmedipham

LD50

Dogs

>4,000

LD50

Chickens

>3,000

Picrolinic acid derivative

Picloram

LD50

Cattle

>750

Sheep

>1,000

a Anorexia and weight loss reported. No deaths were reported in dogs at a tebuthiuron dosage of 500 mg/kg body wt.

Herbicides with Potential to Cause Developmental Toxicity in Experimental Animals

Compound

Effects

Atrizine

Disruption of ovarian cycle and induced repetitive pseudopregnancy (rats, at high doses)

Buturon

Cleft palate, increased fetal mortality (mice)

Butiphos

Teratogenic (rabbit)

Chloridazon

Malformations

Chlorpropham

Malformations or other developmental toxicity (mice)

Cynazine

Malformations such as cyclopia and diaphragmatic hernia (rabbits); skeletal variations in rats

2,4-Da or 2,4,5-Ta alone or in combination

Malformations such as cleft palate, hydronephrosis; teratogenic (mice, rats)

Dichlorprop

Teratogenic (mice); affect postnatal behavior (rats)

Dinosebb

Multiple defects (mice, rabbits)

Dinoterb

Skeletal malformations (rats); skeletal, jaw, head, and visceral (rabbits)

Linuron

Malformations (rats)

Mecoprop

Malformations (mice only)

Monolinuron

Cleft palate (mice)

MCPAc

Teratogenic and embryotoxic (rats), teratogenic (mice)

Prometryn

Head, limbs, and tail defects (rat)

Propachlor

Slightly teratogenic (rats)

Nitrofenb

Malformations (mice, rats, hamsters)

Silvex

Teratogenic (mice)

TCDDa

Malformations/teratogenic (fetotoxicity in chickens, rats, mice, rabbits, guinea pigs, hamsters, and monkeys)

Tridiphane

Malformations such as cleft palate (mice); skeletal variations (rats)

a TCDD is a common contaminant during the manufacturing process of some herbicides such as 2,4-D and 2,4,5-T.

b Obsolete

c 2-methyl-4-chlorophenoxyacetic acid

Resources In This Article

Also of Interest

MManual

Test your knowledge

The acronym SLUD stands for salivation, lacrimation, urination, and defecation, which are the clinical signs associated with muscarinic cholinergic overstimulation caused by certain toxins. Signs of SLUD are most consistent with exposure to which of the following classes of chemicals?