SPECTRUM

Chemical Fact Sheet

Chemical Abstract Number (CAS #) 1912249
CASRN 1912-24-9
SynonymsAtrazine
2-Chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine
Analytical Methods EPA Method 505
EPA Method 525.2
EPA Method 619
EPA Method 8141
Molecular FormulaC8H14ClN5

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

Use ATRAZINE IS A WIDELY USED SELECTIVE HERBICIDE FOR CONTROL OF BROADLEAF & GRASSY WEEDS IN CORN, SORGHUM, RANGELAND, SUGARCANE, MACADAMIA ORCHARDS, PINEAPPLE, & TURF GRASS SOD. IT IS USED ALSO IN SOME AREAS FOR SELECTIVE WEED CONTROL IN CONIFER REFORESTATION & CHRISTMAS TREE PLANTATION AS WELL AS FOR NONSELECTIVE CONTROL OF VEGETATION IN CHEMICAL FALLOW. ATRAZINE ALSO IS USED AS A NONSELECTIVE HERBICIDE FOR VEGETATION CONTROL IN NONCROP LAND. Selective pre- & post-emergence herbicide used in asparagus, forestry, grasslands, grass crops, roses. Crisazina pre and early postemergence on African oil palm, bananas, citrus groves, coffee, corn, pineapples, sorghum, sugarcane.
Consumption Patterns 96% AS AN AGRICULTURAL HERBICIDE FOR GRASSES & BROADLEAF WEEDS (PRINCIPALLY ON CORN, SORGHUM & SUGARCANE); 2% AS A HERBICIDE IN INDUSTRIAL & COMMERCIAL APPLICATIONS (IN RE-FORESTATION); 2% AS A HERBICIDE FOR HOME & GARDEN USE (ON TURF) (1972).
Apparent Color WHITE, CRYSTALLINE ; COLORLESS POWDER
Odor Odorless
Melting Point 171-174 DEG C
Molecular Weight 215.68
Density 1.187 g/cu cm @ 20 deg C
Environmental Impact Atrazine may be released into the environment via effluents at manufacturing sites and at points of application where it is employed as a herbicide. The s- triazine ring of atrazine is fairly resistant to degradation. 2-Chloro-4- ethyl-amino-6-amino-s-triazine, 2-chloro-4-amino-6-isopropylamino-s-triazine, 2-hydroxy-4-ethylamino-6-isopropyl-amino-s-triazine and 2-hydroxy-4- ethylamino-6-amino-s-triazine have been identified as microbial transformation products of atrazine. Chemical degradation of atrazine may be more important environmentally than biodegradation. Atrazine may hydrolyze fairly rapidly in either acidic or basic environments, yet is fairly resistent to hydrolysis at neutral pHs. Furthermore the rate of hydrolysis was found to drastically increase upon small additions of humic materials, indicating atrazine hydrolysis could be catalyzed. For example, the half-life of atrazine at 25 deg C and pH of 4 was 244 days without an additive and 1.73 days with the presence of 2% humic acid. At 25 deg C, a 5 mg/l solution of fulvic acid (naturally occurs in soils and most surface waters) resulted in half-lives of 34.8, 174, 398 and 742 days at pHs of 2.9, 4.5, 6.0 and 7.0, respectively. Hydrolysis of atrazine followed first order kinetics producing hydroxyatrazine as the transformation product. Photolysis of atrazine did not occur in alcohols and water at wavelengths > 300 nm. However, at wavelengths greater than or equal to 290 nm, the photolysis half-life of atrazine at a concn of 10 mg/l in aqueous solution at 15 deg C was 25 hr as compared to a half-life of 4.9 hr for identical conditions with an acetone sensitizer added at a concn of 1 ml/100 ml. Atrazine is expected to maintain a very high to medium mobility class in soils and should not strongly absorb to sediments. Atrazine is not expected to bioconcentrate or volatilize. However if released to the atmosphere, vapor phase reactions with photochemically produced hydroxyl radicals in the atmosphere may be important (estimated half-life of about 2.6 hr). The most probable exposure would be occupational exposure, which may occur through dermal contact or inhalation at places where atrazine is produced or used as a herbicide.
Environmental Fate IN LAB MODEL ECOSYSTEM STUDY, WITH (14)C RING-LABELED ATRAZINE THE ENVIRONMENTAL DEGRADATION PRODUCTS WERE 2-AMINO-4-CHLORO-6-ISOPROPYLAMINO-S-TRIAZINE & 2-AMINO-4-CHLORO -6-ETHYLAMINO-S-TRIAZINE. THERE WAS ONLY A SLIGHT DEGREE OF FOOD-CHAIN TRANSFER OF ATRAZINE (ECOLOGICAL MAGNIFICATION 11 TIMES IN FISH) OR ANY OF ITS DEGRADATION PRODUCTS. TERRESTRIAL FATE: The s-triazine ring of atrazine is fairly resistant to degradation. For example after 70 days, less than one percent of the C(14) labeled atrazine treated at 10, 1000 and 20,000 ppm to a Webster soil was recovered as CO2 while only 10-20% was transformed to 2-chloro-4-ethyl-amino-6-amino-s-triazine, 2-chloro-4-amino-6- isopropylamino-s-triazine, 2-hydroxy-4-ethylamino-6-isopropyl-amino-s-triazine and 2-hydroxy-4-ethylamino-6-amino-s-triazine . However 14, 70 and 80% of the radio-labeled atrazine treated to a Cecil soil at concn of 10, 1000 and 20,000 ppm was recovered intact . The same transformation products were identified and at all concn less than one percent of the parent material was metabolized to CO2 . A 50% reduction of 1 ppm atrazine was achieved within 130 days based on CO2 evolution from 5 differing soils incubated at 25 deg C . Only 0.49 and 0.76% of C(14) labeled atrazine evolved as CO2 from a soil/barley plant system treated at concn of 1 and 6 ppm, respectively, after 7 days, whereas 1.69% of 1 ppm the radiolabeled atrazine evolved from a soil system planted with maize . TERRESTRIAL FATE: Chemical degradation of atrazine may be more important environmentally than biodegradation in soil. Atrazine may hydrolyse in either acidic or basic soils yet is fairly resistent to hydrolysis at neutral pHs. Furthermore the rate of hydrolysis was found to drastically increase upon small additions of humic materials, indicating atrazine hydrolysis could be catalyzed. For example the half-life of atrazine at 25 deg C and pH of 4 was 244 days without an additive and 1.73 days with the presence of 2% humic acid . At 25 deg C, a 5 mg/l solution of fulvic acid (naturally occurs in soils) at pHs of 2.9, 4.5, 6.0 and 7.0 resulted in half-lives of 34.8, 174, 398 and 742 days, respectively . Hydrolysis of atrazine followed first order kinetics producing hydroxyatrazine as the transformation product(1-3). Atrazine has the potential to photolyse from surface soils. The half-lives for sunlight exposed ring-labeled atrazine at concn of 0.10 ppm under aerobic conditions were 330 and 385 days for two agricultural soils . Atrazine is expected to maintain a very high to medium mobility class in soils. Volatilization of atrazine is not expected to be environmentally important. AQUATIC FATE: The s-triazine ring of atrazine is fairly resistant to microbial attack based upon a number of soil studies. Chemical degradation of atrazine may be more important environmentally than biodegradation. Atrazine may hydrolyse fairly rapidly in either acidic or basic waters, yet is fairly resistent to hydrolysis at neutral pHs. Furthermore the rate of hydrolysis was found to drastically increase upon small additions of humic materials, indicating atrazine hydrolysis could be catalyzed. For example the half-life of atrazine at 25 deg C and pH of 4 was 244 days without an additive and 1.73 days with the presence of 2% humic acid . At 25 deg C, a 5 mg/l solution of fulvic acid (naturally occurs in surface waters) at pHs of 2.9, 4.5, 6.0 and 7.0 resulted in half-lives of 34.8, 174, 398 and 742 days, respectively . Hydrolysis of atrazine followed first order kinetics producing hydroxyatrazine as the transformation product(1-3). Alkaline hydrolysis proceeds twice as rapid as acidic hydrolysis . AQUATIC FATE: Photolysis of atrazine did not occur in methanol, ethanol, butanol and water at wavelengths > 300 nm . However at wavelengths greater than or equal to 290 nm, the photolysis half-life of atrazine at a concn of 10 mg/l in aqueous solution at 15 deg C was 25 hr as compared to a half-life of 4.9 hr for identical conditions with an acetone sensitizer added at a concn of 1ml/100ml . The half-lives for sunlight exposed ring-labeled atrazine at concn of 0.10 ppm under aerobic conditions were 15 and 20 days for two estuarine sediments and 3-12 days for estuarine water . Hydroxyatrazine (2-hydroxy-4-ethylamino-6-isopropylamino-s-triazine) was identified as the major short-term metabolite . Atrazine is not expected to strongly absorb to sediments and may only moderately partition from the water column. Bioconcentration and volatilization of atrazine are not expected to be environmentally important. ATMOSPHERIC FATE: If released to the atmosphere, reactions with photochemically produced hydroxyl radicals in the atmosphere may be important. The rate constant for the vapor-phase reaction of atrazine with photochemically produced hydroxyl radicals has been estimated to be 147.2X10-12 cu cm/molecule-sec at 25 deg C which corresponds to an atmospheric half-life of about 2.6 hr at an atmospheric concn of 5X10 5 hydroxyl radicals per cu cm . TERRESTRIAL FATE: Atrazine was applied to a field planted with corn for 20 yr at rates ranging 1.40-2.24 kg/ha. Analysis of soil samples taken 6 & 12 mo after the final application showed the presence of residues of the parent cmpd & its mono dealkylated hydroxy analogs. Long-term annual applications of atrazine for weed control in corn apparently result in the persistence of some of its degradation products, mainly hydroxylated analogs, in soil 1 yr after the final herbicide application. Such residues may enter the food crops planted in atrazine-treated soil in the year or years following the cessation of a long-term treatment. TERRESTRIAL FATE: The accumulation of atrazine was studied in 8 corn-planted soils, treated with 1-2 kg atrazine/ha/yr for about 15 yr. The atrazine residues were 0.012-0.02 ppm. The atrazine degradation products showed the following residues: deethylatrazine, 0.003-0.014 ppm; deisopropylatrazine, 0.002-0.004 ppm; deethyldeisopropylatrazine, 0.002-0.04 ppm, and hydroxyatrazine, about 0.01 ppm. C-Cl bond hydrolysis in atrazine was enhanced by acid soils. TERRESTRIAL FATE: In the spring, 1973 loamy soil was treated with (14)C ring-labeled atrazine. In the summer, 1981, soil samples were collected & analyzed. The soil still contained about 83% from the initial (14)C activity. Only 40% could be extracted from those samples. Besides traces of atrazine, 6 metabolites were identified which originated from the parent cmpd through N-dealkylation and hydrolysis. TERRESTRIAL FATE: In soil, microbial degradation occurs, with half-life of about 6-10 wk. TERRESTRIAL FATE: THE PERSISTENCE IN SOIL & TRANSPORT OF ATRAZINE IN SURFACE & SUBSURFACE RUNOFF FROM PLOTS IN COASTAL PLAIN OF THE SOUTHERN UNITED STATE WERE STUDIED. ATRAZINE PERSISTED IN SOIL SURFACE (10 CM) FOR MORE THAN 4 MONTHS; HOWEVER, IT COULD NOT BE DETECTED AT GREATER DEPTHS AFTER 2 MONTHS. IT WAS NOT DETECTED IN SIGNIFICANT SURFACE RUNOFF AFTER 26 DAYS OR IN SUBSURFACE FLOW. TERRESTRIAL FATE: DEGRADATION PRODUCTS OF CYPRAZINE & ATRAZINE WERE MONITORED OVER A 3-YEAR PERIOD IN SOIL (PREDOMINANTLY LOAMY SANDS & SAND CLAY LOAMS) IN FIELDS USED TO GROW MAIZE. THE LEVEL OF HYDROXYTRIAZINES IN SOIL SAMPLES RANGED FROM 0.05 TO 0.5 PPM & THEY WERE THE PREDOMINANT TRIAZINE RESIDUES IN THE FIELDS DURING SPRING & AUTUMN. TERRESTRIAL FATE: THE LONG SOIL PERSISTENCE OF THESE CMPD DOES CREATE THE PROBLEM OF SOIL CARRY OVER, WHICH CAN DAMAGE SUCCEEDING CASH CROPS. THEREFORE EXTREME CAUTION MUST BE TAKEN IN THEIR APPLICATION ON CROPLAND TO AVOID SUCH INJURY TO FOLLOWING CROPS. TRIAZINES
Drinking Water Impact SURFACE WATERS: Atrazine concn ranged from 0.1 to 23.2 ug/l for 13 Ohio streams flowing into Lake Erie and from 1.0 to 45.7 ug/l for 8 sites in the Sandusky River basin, North Ohio . For the dissolved fraction, 35% of 107 samples from 10 sites in the Cape Fear river basin, NC tested positive for atrazine at concn up to 131.0 ug/l with an average of 5.6 ug/l; for the particle fraction, 22% of 106 samples tested positive at concn up to 5.2 ug/l with an average of 0.4 ug/l . Atrazine concn averaged 1.6 ng/g and 77% of the Canadian streams tested positive for atrazine at entry points to the Great Lakes with a maximum atrazine level of 26.0 ng/g . DRINKING WATER: The 7 day average concn of atrazine in 3 New Orleans LA drinking water supplies ranged from 4.9 to 5.4 ug/l . Atrazine in Iowa's drinking water supplies from the South Skunk, Racoon, Desmoines, and Rathburn Rivers, Red Rock Reservoir, 3 municipal wells of Demoines, Davenport and Iowa City, and 4 raw drinking water wells ranged in concn from NA-12,000, 120-3300, 50-800, 165-3750, 100-1900, 60-405 and 4-483 ng/l, respectively . The South Skunk, Racoon, Desmoines, and Rathburn Rivers and Red Rock Reservoir maintained respective average atrazine concn of 200, 814, 211, 1285 and 921 ng/l . GROUNDWATER: In corn producing regions of Nebraska, atrazine was found in ground water at concn ranging from 200 to 800 ng/l . Concn of atrazine in 14 irrigation wells in central Nebraska ranged from 0.06 to 3.12 ug/l . Atrazine was applied to plots which were drained by tiles. Water samples were collected & analyzed. Concn during the first season ranged from 0.000 to 0.68 ug/l. The deethylated metabolite, 2-chloro-4-isopropylamino-6-amino-s-triazine, was detected at similar concn. SURFACE WATER: A SURVEY OF AGRICULTURAL WATERSHEDS IN SOUTHERN ONTARIO, 1975-1977, NEAR LAND DEVOTED TO CORN PRODN TREATED WITH ATRAZINE @ MEAN RATE OF 1.7 KG/HA, WAS CONDUCTED. STREAMS WERE GAUGED & WATERS MONITORED. ATRAZINE & ITS METABOLITE DESETHYLATRAZINE WERE DETECTED IN 80% OF STREAM WATERS @ 1.4 UG/L.

DISCLAIMER - Please Read

Florida-Spectrum List of Services
Florida-Spectrum Homepage