SPECTRUM

Chemical Fact Sheet

Chemical Abstract Number (CAS #) 709988
CASRN 709-98-8
SynonymsPropanil
Propanamide, N-(3,4-dichlorophenyl)-
Apronox
Chem-Rice
Prostar
Prop-Job
Analytical Method EPA Method 632.1
Molecular FormulaC9H9Cl2NO

Link to the National Library of Medicine's Hazardous Substances
Database for more details on this compound.

Use HERBICIDE (CONTACT TYPE); POSTEMERGENCE WITH NO RESIDUAL EFFECT AGAINST NUMEROUS GRASSES AND BROADLEAVED WEEDS IN RICE. IN NEMATOCIDE FORMULATIONS It is used as a herbicide in rice and potato fields Control of many grasses and broad-leaved weeds in potatoes and wheat.
Apparent Color WHITE CRYSTALLINE SOLID ; Colorless solid ; Light brown solid ; Dark oily liquid ; Gray-black solid
Melting Point 85-89 deg C Pure propanil
Molecular Weight 218.09
Density 1.054 AT 25 DEG C/15.6 DEG C
Environmental Impact Propanil is released directly to the environment through its use and application as an agricultural herbicide. If released to soil, microbial degradation is expected to be the major removal process. Propanil will biodegrade to 3,4-dichloroaniline which metabolizes to 3,3',4,4'-tetrachloroazobenzene. Neither leaching nor adsorption (Kocs of 149 and 220) should be important for propanil in relation to biodegradation; its metabolites, however, may chemically bind to soil. The half-life in soil typically ranges from 1 to 3 days; the US Dept of Agriculture's Pesticide Properties Database lists a soil half-life of 1 day. Photolysis may be important on soil surfaces and in near-surface waters based on a half-life of 4 hrs when irradiated with 300 nm sunlight lamps in an acetonitrile and water solvent system. If released to water, propanil will also degrade through microbial degradation (half-lives of 17 and 154 hrs in amended and unamended environmental waters). Hydrolysis, volatilization and bioconcentration in fish will not be important. If released to the atmosphere, propanil will exist in the vapor and particulate phases; vapor phase propanil degrades rapidly by reaction with photochemically produced hydroxyl radicals (estimated half-life of 24 hours). Physical removal from the atmosphere occurs through wet and dry deposition. Photolysis will be important in air. Worker exposure to propanil occurs through dermal contact and inhalation of dust.
Environmental Fate TERRESTRIAL FATE: AT 1 TO 4 KG/HA ITS PERSISTENCE IN SOILS IS BRIEF. When used in flooded rice culture, propanil applied as a foliar spray dissipated within 24 hr after flooding of the rice. 3,4-Dichloroaniline concentration in the flood waters corresponded to the decrease in propanil. Red Rice (Oryza sativa L.) seedlings were the source of an aryl amidase. Studiesshowed that this enzyme was able to hydrolyze propanil, as well as some analogs. Although active between pH 7.4 to 8.7, the optimum was 8.2. Calculations showed the Km = 2.5X10-5 and that the activity was in the order propanil >3'Cl > propionanilide > 4'-Cl greater than or equal to 3'5'-dichloro > 2'-Cl. Propanil was hydrolyzed by Corynebacterium pseudodiphtheriticum NCIB 10803. A strain of Fusarium solani used propanil as a sole source of carbon and energy for growths and the primary product of degradation was 3,4-DCA. This acylamidase did not catalyze hydrolysis of dicryl, karsil, fenuron, monuron or IPC. It seems to be different than acylamidases isolated from rice, rat liver and chick kidney. Studies with rice have shown that diazinon and carbaryl, absorbed from soil and translocated could inhibit propanil hydrolysis. In studies with propanil and 3,4-dichloroaniline, it was observed that in different soils there were differences in the amount of tetrachloroazobenzene formed. Formation of tetrachloroazobenzene did not correlate with soil pH. With five soils of pH 4.5 to 5.5, tetrachloroazobenzene was formed from both compounds; pH 5.8 and 7.4 tetrachloroazobenzene formed from 3,4-dichloroaniline only; pH 3.4 and 6.4, no tetrachloroazobenzene from either substrate. In soil, the conversion of 3,4-dichloroaniline to tetrachloroazobenzene increased with an increase in peroxidase activity. Terrestrial fate: Duration of activity in soil in warm, moist conditions in approximately 1-3 days. TERRESTRIAL FATE: Volatilization and hydrolysis will not be important in soils. Kocs of 149 and 220 suggest weak adsorption may take place. Field tests indicate that leaching to groundwater is not an important transport process in soil(6). Photolysis may be important on terrestrial surfaces based on a half-life of 4 hrs when irradiated with 300 nm sunlight lamps in an acetonitrile and water solvent system(7,SRC). Microbial degradation to 3,4-dichloroaniline and 3,3',4,4'-tetrachloroazobenzene should be the primary fate process of propanil in soil. Propanil's half-life in a soil grab sample at 28 deg C was determined to be 0.1-2.3 days at initial concns of 10-250 ppm, respectively . According to the US Dept of Agriculture's Pesticide Properties Database, the soil half-life of propanil is 1 day . Propanil will persist 1-3 days in or on soil under warm, moist conditions typical of application . Field tests indicate that propanil does not appear to be a threat to groundwater from rice paddy application(8). Volatilization (estimated Henry's Law constant of 4.5X10-9 atm-cu m/mole at 25 deg C(1,SRC)), hydrolysis and bioconcentration in fish (measured BCF of 1.6 ) will not be important in aquatic environments. Kocs of 149 and 220 suggest weak adsorption to sediment and suspended solids. Photolysis may be important in near-surface water based on a half-life of 4 hrs when irradiated with 300 nm sunlight lamps in an acetonitrile and water solvent system(6,SRC). Microbial degradation to 3,4-dichloroaniline should be the primary removal process in water; average aerobic biodegradation half-lives of 17 and 154 hrs were determined for propanil (1 ppm initial concn) in amended and unamended environmental waters(7). Based upon a reported vapor pressure of 4X10-5 mm Hg at 20-25 deg C , propanil can exist in both the vapor and particulate phases in the ambient atmosphere(2,SRC). It will degrade rapidly in the vapor phase by reaction with photochemically produced hydroxyl radicals with an estimated half-life of about 24 hrs(3,SRC). Physical removal from air by wet deposition (dissolution in clouds, rainfall, etc) and dry deposition (particulate settling, etc) will also occur. Photolysis may be important in air based on a half-life of 4 hrs when irradiated with 300 nm sunlight lamps in an acetonitrile and water solvent system(7,SRC).
Drinking Water Impact GROUNDWATER: On July 27, 1988, during heavy use, propanil was detected in 1 of 12 rice paddy groundwater wells (20 m deep maximum) at a concn of 0.04 ug/l in the provinces of Vercelli and Novara, Italy; in December, no propanil was detected in this well . In the same study, propanil was not detected during June, July and December in 12 groundwater wells at least 70 m deep . SURFACE WATER: On July 27,1988, during heavy use, propanil was detected in 5 of 12 river samples at a concn range of 0.1-0.228 ug/l in an area of rice cultivation in the provinces of Vercelli and Novara, Italy. In December, no propanil was detected in these surface waters . EFFL: Draining ditches of rice paddies were remarkably polluted with propanil (no quantification given) during heavy propanil use in June and July of 1988; no propanil was detected in the ditches in December of 1988 .

DISCLAIMER - Please Read

Florida-Spectrum List of Services
Florida-Spectrum Homepage