Cyanazine

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

In case of fire in the surroundings, use appropriate extinguishing media.

Fresh air, rest. Refer for medical attention.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Refer for medical attention .

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

Use with adequate ventilation. Avoid eye, skin contact, breathing dust, or contact with water, feed, or food.

SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants.

LC50 Rasbora heteromorpha (Harlequin fish) 10 mg/l/48 hr /Conditions of bioassay not specified/

LC50 Cyprinodon variegatus (Sheepshead minnow) 18 mg/l/48 hr /Conditions of bioassay not specified/

LC50 Gammarus fasciatus 2.0 mg/l/96 hr @ 15 °C, mature. Static bioassay without aeration, pH 7.2-7.5, water hardness 40-50 mg/l as calcium carbonate and alkalinity of 30-35 mg/l. /Technical material 100%/

LC50 Pimephales promelas (Fathead minnow) 16.3 mg/l/96 hr @ 18 °C (95% confidence interval 14.2-18.0 mg/l), wt 0.9 g. Static bioassay without aeration, pH 7.2-7.5, water hardness 40-50 mg/l as calcium carbonate and alkalinity of 30-35 mg/l. /Technical material 100%/

For more Ecotoxicity Values (Complete) data for CYANAZINE (12 total), please visit the HSDB record page.

TERRESTRIAL FATE: The half-life of cyanazine determined in field studies ranged from 6-30 days (1). The half-life of cyanazine measured under laboratory conditions range from 3-19 days at 30 and 5 degrees C, respectively (34% moisture content) to greater than 200 days at 20 degrees C and 8% moisture content(1). Based on a classification scheme(2) and measured Koc values of 182-372(3,4), cyanazine is expected to have moderate mobility in soil(SRC). Volatilization of cyanazine from moist soil surfaces is not expected to be an important fate process(SRC) given a Henry's Law constant of 2.57X10-10 atm-cu m/mole(5). Cyanazine is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.38X10-07 mm Hg(6). Photodegradation of cyanazine is not expected to be an important fate process(7).

AQUATIC FATE: Based on a classification scheme(1) and measured Koc values of 182-372(2,3), cyanazine is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon a Henry's Law constant of 2.57X10-10 atm-cu m/mole(4). Volatilization was not an important process in a model ecosystem study(5). According to a classification scheme(6), an estimated BCF of 5(SRC), from its log Kow of 2.22(7), suggests the potential for bioconcentration in aquatic organisms is low. A half-life of 30-40 days was measured for cyanazine in constructed wetlands; the cyanazine metabolites deethylcyanazine and cyanazine amide were detected in the constructed wetlands(8). At 25 °C and pH range 5.5-9, the un-catalyzed aqueous hydrolysis half-life is at least 200 days(9). Laboratory studies have suggested, however, that natural water constituents, such as humic and fulvic acid, may catalyze the chemical hydrolysis(10).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), cyanazine, which has a vapor pressure of 1.38X10-7 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase cyanazine is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 41 hours(SRC), calculated from its rate constant of 9.31X10-12 cu cm/molecule-sec at 25 °C(SRC), determined using a structure estimation method(3). Particulate-phase cyanazine may be removed from the air by wet and dry deposition(SRC). Cyanazine has been detected in widespread rainwater monitoring studies(4); degradation rates while associated with rainwater and clouds are unknown(SRC); these monitoring studies suggest that widespread atmospheric dispersal is possible(4).

Reproductive Toxin - A chemical that is toxic to the reproductive system, including defects in the progeny and injury to male or female reproductive function. Reproductive toxicity includes developmental effects. See Guidelines for Reproductive Toxicity Risk Assessment.

Organic nitriles decompose into cyanide ions both in vivo and in vitro. Consequently the primary mechanism of toxicity for organic nitriles is their production of toxic cyanide ions or hydrogen cyanide. Cyanide is an inhibitor of cytochrome c oxidase in the fourth complex of the electron transport chain (found in the membrane of the mitochondria of eukaryotic cells). It complexes with the ferric iron atom in this enzyme. The binding of cyanide to this cytochrome prevents transport of electrons from cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted and the cell can no longer aerobically produce ATP for energy. Tissues that mainly depend on aerobic respiration, such as the central nervous system and the heart, are particularly affected. Cyanide is also known produce some of its toxic effects by binding to catalase, glutathione peroxidase, methemoglobin, hydroxocobalamin, phosphatase, tyrosinase, ascorbic acid oxidase, xanthine oxidase, succinic dehydrogenase, and Cu/Zn superoxide dismutase. Cyanide binds to the ferric ion of methemoglobin to form inactive cyanmethemoglobin. (L97)

In a study of two watersheds in GA, seasonal losses of cyanazine via field runoff have been reported to range from 0.07 to 1.0% of total field application(1). The daily flux of cyanazine to the Mississippi River and 6 of its tributaries from agricultural use was estimated for the period between May 1991 through March 1992; the estimated daily fluxes over the 11 month period were summed to produce the following total estimated discharges over the 11 month period: Minnesota River: 5.9 kg; White River: 1.6 kg; Illinois River: 23 kg; Platte River: 12 kg; Missouri River: 40 kg; Ohio River: 11 kg; Mississippi River at Clinton, IA: 9.1 kg; Mississippi River at Thebes, IL: 99 kg; Mississippi River at Baton Rouge, LA: 130 kg(2).

An experimentally determined Koc of 200 has been reported (soil type not given)(1). A Koc of 182 was measured in a silty soil(2). Using soil TLC, an intermediate mobility was measured in a silty clay loam (Rf of 0.39) and a high mobility was measured in a sandy loam (Rf of 0.74)(3); the avg Koc for these two soils was reported as 372(4). A Koc of 97 was measured for a silt loam soil from a corn field(5); in field studies using this soil (0.70% organic carbon), a max of 0.04% of surface application was lost through subsurface tile drains(5). In field studies, cyanazine did not leach below a 0.20 m depth in a sandy loam soil(6) or below a 0.30 m depth in a silt loam soil(7). However, cyanazine leached through 0.90 m of a soil composed of 29% clay, 49% silt and 22% sand(8). Cyanazine is reversibly adsorbed to soil particles(9); adsorption increases with increased organic matter content, decreasing soil water and decreasing pH(9). The adsorption of cyanazine by microbial biomass has been observed(10). According to a classification scheme(11), the measured Koc values suggest that cyanazine is expected to have moderate to high mobility in soil(SRC).

Cyanazine's use as a pesticide for the control of annual grasses and broadleaf weeds(1) is expected to result in its direct release to the environment(SRC). However, in the US, registration is canceled as of January 1, 2000(2). Sale and distribution of existing stock may continue through September 30, 2002, and all use is prohibited after December 31, 2002(2).

AEROBIC: The half-life of 2.0 ppm of cyanazine in samples of Regina Heavy Clay soil (70% clay, 25% silt and 5% sand) was determined under various laboratory soil moisture and temperature conditions(1). The half-life at 34% soil moisture content varied from 19 to 3 days at temperatures of 5 and 30 degrees C, respectively; at 8% moisture content and 20 degrees C, the half-life was greater than 200 days (1). In field experiments, the half-life of cyanazine, initially applied at approximately 5.5 lbs/acre, was approximately 30 days; after 56 days, less than 10% of the cyanazine remained(1). In the lab and field experiments, the degradation of cyanazine occurred more rapidly than metribuzin and atrazine(1). The degradation of cyanazine was measured under field conditions over a four year period and under different tillage treatments(2). Approximately 8 percent of cyanazine, initially applied at 5.5-8.8 lbs/acre, remained 2 and 4 weeks after application under no-till and conventional tilling conditions, respectively(2). Approximately 19 and 24 percent of cyanazine, initially present at 250 umol/kg, remained after 42 days in a silt loam soil that was amended with ryegrass and cornmeal, respectively; 36 percent of the applied cyanazine remained in unamended soil and soil amended with poultry litter(3). Three metabolites of cyanazine were observed (in decreasing order): hydroxy cyanazine, cyanazine amide and deethyl cyanazine(3). In a cyanazine metabolite study, cyanazine amide and de-isopropylated atrazine were detected as soil degradation products(4); it was proposed that hydrolysis preceded microbial degradation to yield the de-isopropylated atrazine(4). Persistence studies over a 20-week period at varying temperatures (5, 20, 35 and 50 °C) found that cyanazine degraded within 10 weeks at 5 °C and within 5 weeks at the higher temperatures(5); the initial observed half-lives at the higher temperatures were 1.5-2.0 weeks(5); it has been suggested that degradation of cyanazine at -10 °C is not very likely(6). A half-life of 6 days was observed in a cornfield study in Quebec, Canada(7).

AEROBIC: The persistence and fate of cyanazine was studied in a model aquatic ecosystem(1); after 35 days, only 18% of the initial cyanazine remained(1); the following metabolites were identified(1): 60% N-deethylcyanazine, 0.8% cyanazine amide, 0.3% N-deethylcyanazine amide, 1.2% unknown polar metabolites, and 19% unextractable metabolites(1); degradation of the triazine ring to CO2 proceeded slowly(1); cyanazine and its metabolites did not bioconcentrate in the food chain(1). Cyanazine was found to resist microbial degradation in distilled water amended with various inocculum under aerobic and anaerobic conditions in laboratory experiments(2). A half-life of 30-40 days was measured for cyanazine in constructed wetlands; the cyanazine metabolites deethylcyanazine and cyanazine amide were detected in the constructed wetlands(3). The exact degradation mechanism in water has not been determined with certainty, but may be a combination of microbial degradation and catalyzed hydrolysis(SRC).

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Cyanazine is found on List A, which contains most food use pesticides and consists of the 194 chemical cases (or 350 individual active ingredients) for which EPA issued registration standards prior to FIFRA, as amended in 1988. Case No: 0066; Pesticide type: herbicide; Registration Standard Date: 12/31/94; Case Status: No products containing the pesticide are actively registered ... The case /is characterized/ as "cancelled." Under FIFRA, pesticide producers may voluntarily cancel their registered products. EPA also may cancel pesticide registrations if registrants fail to pay required fees or make/meet certain reregistration commitments, or if EPA reaches findings of unreasonable adverse effects.; Active ingredient (AI): Cyanazine; AI Status: OPP has completed a Reregistration Eligibility Decision (RED) document for the case/AI.

(AZ) ARIZONA 9 ug/l

(FL) FLORIDA 14 ug/l

(ME) MAINE 1.4 ug/l

(MN) MINNESOTA 1 ug/L

(WI) WISCONSIN 1 ug/l

Used as pre- and post-emergence herbicide for control of annual grasses and broadleaf weeds; [HSDB]

Product registrations voluntarily cancelled in 1999; [ACGIH] Banned in the EU for use as pesticide for plant protection and other pesticides including biocides; [eChemPortal: ESIS]

Farming (Pesticides) [Category: Industry]

For Cyanazine (USEPA/OPP Pesticide Code: 100101) ACTIVE products with label matches. /SRP: Registered for use in the U.S. but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./

No products containing the pesticide are actively registered ... The case /is characterized/ as "cancelled."

A pre and postemergence herbicide for control of annual grasses and broadleaf weeds.

Acetone cyanohydrin + ammonia + cyanuric chloride + ethylamine (amine formation/amine formation/amine formation)

Prepn: Brit pat 1,132,306; W. Schwarze, U.S. pat 3,505,325 (1968 1970 both to Degussa).

USEPA/OPP Pesticide Code 100101; Trade Names: Bladex; Payze; SD 15418; Bladex 80WP; Cyanazine SD 15418; DW 3418; fortol; Fortrol; WL 19805.

Available as a granular product, wettable powder, flowable concentrate, emulsifiable concentrate, and soluble concentrate. Sold in combination with atrazine, alachlor, metolachlor, paraquat, and butylate.

Dry flowable, liquid

Technical grade >95% pure

Suspension concentrate, wettable powder, granule, DF

Pharmaceuticals

Herbicides

HERBICIDES

Reported application rates vary, 0.54-4.8 lb/acre depending upon the crop.

U.S.: Registration is canceled as of January 1, 2000. Sale and distribution of existing stock may continue through September 30, 2002, and all use prohibited after December 31, 2002.