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The information in this profile may be out-of-date. It was last revised in 1996. EXTOXNET no longer updates this information, but it may be useful as a reference or resource.

Please visit the National Pesticide Information Center (NPIC) to find updated pesticide fact sheets. If you don't find a fact sheet related to your question, feel free to call 1-800-858-7378. NPIC is open five days a week from 8:00am to 12:00pm Pacific Time.

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E X T O X N E T

Extension Toxicology Network

Pesticide Information Profiles

A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Oregon State University, the University of Idaho, and the University of California at Davis and the Institute for Environmental Toxicology, Michigan State University. Major support and funding was provided by the USDA/Extension Service/National Agricultural Pesticide Impact Assessment Program.

EXTOXNET primary files maintained and archived at Oregon State University

Revised June 1996

Propanil

Trade and Other Names: Trade names include Arrosol, Bay 30130, Cekupropanil, Chem-Rice, DPA, DCPA, Dropaven, Erban, FW-734, Herbax, Prop-Job, Propanex, Propanilo, Riselect, S 10145, Stam, Stam 80 EDF, Stam M-4, Stampede, Strel, Supernox, Surcopur, Surpur, Vertac, Wham DF, and Wham EZ.

Regulatory Status: Propanil is a General Use Pesticide (GUP). Propanil is in toxicity class II - moderately toxic, due to its potential to irritate eyes and skin. Products containing propanil bear the Signal Word WARNING.

Chemical Class: acetanilide

Introduction: Propanil is an acetanilide post-emergence herbicide with no residual effect. It is used against numerous grasses and broad-leaved weeds in rice, potatoes, and wheat. It is available as emulsifiable concentrates, liquid and dry flowable, low volume, and ultra low volume (ULV) formulations. Mixing with carbamates or organophosphorans compounds is not recommended. The information presented here, unless otherwise noted, pertains to technical propanil.

Formulation: It is available as emulsifiable concentrates, liquid and dry flowable, low volume, and ultra low volume (ULV) formulations.

Toxicological Effects:

• Acute toxicity: Propanil is moderately toxic via ingestion. The reported rat oral LD50 values for technical propanil range from 1080 mg/kg to greater than 2500 mg/kg [8,58]; and for formulations range from 500 to greater than 5000 mg/kg [58]. The oral LD50 is 1217 mg/kg for technical propanil in dogs [87]. Technical propanil is practically nontoxic via the dermal route, with a reported LD50 of greater than 5000 mg/kg (58) in rabbits. The LD50 in rats suggests slight dermal toxicity (less than 2000 mg/kg) for one formulated product, Propanil 4 [58]. However, the reported LD50 values in rats and rabbits indicate moderate to practically no dermal toxicity (greater than 2000 mg/kg) for four other formulated products: Wham DF, Wham EZ, Stam 80 EDF, and Stam M-4 [58]. Technical propanil is moderately toxic via the inhalation route, with a reported 4-hour LC50 of 1.12 mg/L [8,58]. The formulated products may be less toxic, with inhalation 4-hour LC50 values of 2.8 mg/L for Stam M-4 and 6.1 mg/L for Stam 80 EDF [58].
• Chronic toxicity: In a 2-year study, a dietary level of about 80 mg/kg/day caused a decrease in overall growth and a relative increase in the weight of the spleen and liver in female rats and of the testes in males [87]. Feed consumption, growth, and hemoglobin levels in rats were reduced at daily doses of about 180 mg/kg/day over 3 weeks [87]. In a 2-year study in dogs, a dietary level of about 85 mg/kg/day depressed growth in spite of increased food intake and increased relative liver weight [87]. The only other change detected was a slight increase in the relative weight of the heart [87]. Liver and blood changes and cyanosis was seen at 25 mg/kg/day in mice over 90 days [87].
• Reproductive effects: In a three-generation study, male and female rats fed doses as high as 50 mg/kg/day of propanil for 11 weeks before mating showed no effect on fertility, gestation, viability, or lactation [8]. It appears that propanil does not cause reproductive effects.
• Teratogenic effects: No evidence of teratogenic effects was observed in studies with rats and rabbits [58,125].
• Mutagenic effects: In vitro tests of propanil, including the Ames test (with and without metabolic activation), tests on mammalian cell cultures, and cytogenetic assays on mice, failed to show mutagenic or genotoxic effects [58,125].
• Carcinogenic effects: No evidence of carcinogenicity was observed in long-term studies of mice and rats [58].
• Organ toxicity: Data from animal studies indicate that the most likely target organs are the liver, kidney, spleen, and possibly testes [87]. Dermatitis (rashes) and sensitization (allergies) are possible. High doses may produce anemia due to the formation of methemoglobin [87].
• Fate in humans and animals: When propanil was fed to a cow for 4 days, 1.4% of the total dose was recovered in the feces, but none was detected in the urine or milk [87]. This suggests that propanil is absorbed into the bloodstream through the gastrointestinal tract and that, once in the bloodstream, propanil is metabolized by the body. Propanil is lipid (fat) soluble. The liver breaks down propanil to aniline derivatives. These metabolites are responsible for the methemoglobin formation [70]. Excretion is through the urine.

Ecological Effects:

• Effects on birds: Propanil is moderately toxic to birds. The oral LD50 for propanil in bobwhite quail is 196 mg/kg, and in mallard ducks is 275 mg/kg [58]. The 8-day dietary LC50 for propanil in bobwhite quail is 2861 ppm, and in mallard ducks is 5627 ppm [58].
• Effects on aquatic organisms: Propanil may be moderately to highly toxic to a wide range of aquatic species [58]. The 96-hour LC50 for propanil is 5.4 mg/L in bluegill sunfish, 2.3 mg/L in rainbow trout, and 4.6 mg/L in sheepshead minnows [58]. The 48-hour LC50 for propanil in Daphnia magna, a small freshwater crustacean, is 0.14 mg/L, and for mysid shrimp is 0.4 mg/L [58]. The 96-hour LC50 of propanil is 5.8 mg/L in the Eastern oyster [58]. The compound concentrated to levels up to 111 times the background water concentration in fathead minnows. The level of pesticide in the minnows returned to normal within 10 days after the fish were placed in a propanil-free enviroment. This indicates that the compound is not likely to concentrate appreciably in aquatic organisms.
• Effects on other organisms: Propanil is nontoxic to honeybees, with a reported contact LC50 of 240 ug/bee [1].

Environmental Fate:

• Breakdown in soil and groundwater: Propanil is of low soil persistence [58,11]. The field half-life is 1 to 3 days [58,11]. Propanil is soluble in water and it adsorbs only weakly to soil particles. Propanil is rapidly broken down in the soil by microorganisms, which have highest activity under warm, moist conditions. Bacteria produce by-products such as tetrachloroazobenzene and dichloroaniline [58]. Its rapid breakdown in soil practically eliminates the potential for groundwater contamination [11].
• Breakdown in water: Propanil will rapidly break down in water due to microbial activity, the major breakdown pathway. Reported half-lives are 2 days under aerobic conditions and 2 to 3 days under anaerobic conditions [58].
• Breakdown in vegetation: Within a plant, propanil is moved from the leaves to the growing shoots, then back to other leaves. It is a contact herbicide. Resistant crop plants such as rice completely metabolize propanil [58]. Carry over of herbicidal activity to subsequent crops is not likely. Propanil may be highly phytotoxic to non-target plants if mixed with carbamates or organophosphates [1].

Physical Properties:

• Appearance: The technical product is brownish, crystalline solid with an organic acid odor [58]. It is stable in emulsion concentrates, but is hydrolyzed in extremely acid or basic conditions [58].
• Chemical Name: 3',4'-dichloropropionanilide [1]
• CAS Number: 709-98-8
• Molecular Weight: 218.08
• Water Solubility: 225 mg/L @ 25 C [1]
• Solubility in Other Solvents: v.s in benzene, ethanol, acetone, and cyclohexanone; s. in toluene and xylene [1]
• Melting Point: 81-91 C (technical) [1]
• Vapor Pressure: 12 mPa @ 60 C [1]
• Partition Coefficient: 2.2856 [1]
• Adsorption Coefficient: 149 [11]

Exposure Guidelines:

• ADI: Not Available
• MCL: Not Available
• RfD: 0.005 mg/kg/day [13]
• PEL: Not Available
• HA: Not Available
• TLV: Not Available

Basic Manufacturer:

Rohm and Haas Co.
Agricultural Chemicals
100 Independence Mall West
Philadelphia, PA 19106

• Phone: 215-592-3000
• Emergency: Not Available
  

References:

References for the information in this PIP can be found in Reference List Number 10

DISCLAIMER: The information in this profile does not in any way replace or supersede the information on the pesticide product labeling or other regulatory requirements. Please refer to the pesticide product labeling.