Prometryn

Pesticide -> EPA IRIS

Herbicides

Active substance -> EU Pesticides database: Not approved

Pesticides -> Herbicides, Triazine

Pesticide

Pesticides -> Herbicides -> Triazine herbicides -> Methylthiotriazine herbicides

log Kow = 3.51

3.36

Crystals

White powder

WHITE SOLID

Solubilities in organic solvents at 25 °C. [Table#4783]

Solubilities in organic solvents at 20 °C [Table#4784]

In water solubility, 33 mg/L at 25 °C

0.000002 [mmHg]

1.24X10-6 mm Hg at 25 °C

This chemical does not meet GHS hazard criteria for 3.2% (3 of 94) of reports.

Warning

H332 (43.6%): Harmful if inhaled [Warning Acute toxicity, inhalation]

P261, P271, P273, P304+P340, P317, P391, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 94 reports by companies from 8 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Warning

Hazard Traits - Environmental tox

Prometryn is listed in the dataset of EPA Human Health Benchmarks for Pesticides under the Safe Drinking Water Act (40 eCFR 141)

Status: Active Update: 15-02-2022 https://echa.europa.eu/registration-dossier/-/registered-dossier/32336

Prometryn: Does not have an individual approval but may be used under an appropriate group standard

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

For the triazine herbicides, systemic toxicity unlikely unless large amounts are ingested; May cause irritation; [EPA Pesticides, p. 121] A mild eye irritant; [HSDB] May cause irritation; [MSDSonline] 2021 TLV Basis: liver and kidney damage, bone marrow effects. and maternal and fetal toxicity; No human studies available; [ACGIH]

The major hazards encountered in the use and handling of prometryne stem from its toxicologic properties. Toxic by inhalation and ingestion, exposure to this colorless to white, crystalline substance may occur from its manufacture, formulation, and use as an herbicide. Effects from exposure may include shortness of breath, muscle spasms, ataxia, and anorexia. In activities and situations where over exposure may occur, wear a self-contained breathing apparatus and personal protective clothing. If contact should occur, immediately flush affected skin or eyes with running water for at least 15 minutes. Remove contaminated clothing and shoes at the site. While prometryne does not ignite easily, it may burn with the production of irritating and poisonous gases. For fires involving prometryne, extinguish with dry chemical, CO2, Halon, water spray, fog, or standard foam. Prometryne may be shipped domestically via air, rail, road, and water, in containers bearing the label "Poison". Small dry spills of prometryne may be placed into a clean, dry, covered container for later disposal (liquid solutions are first absorbed in sand or other noncombustible absorbent). Large liquid spills should be diked far ahead to prevent prometryne from entering water sources and sewers. Before implementing land disposal of prometryne, consult with regulatory agencies for guidance.

USEPA/Office of Pesticide Programs; Reregistration Eligibility Decision Document - Prometryn EPA 738-R-95-033 (February 1996). The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the U.S.[Available from, as of February 28, 2007: http://www.epa.gov/pesticides/reregistration/status.htm]

Tolerances are established for residues of the herbicide prometryn (2,4-bis(isopropylamino)-6-methylthio-s-triazine) in or on the following raw agricultural commodities: [Table#4780]

Tolerances with regional registration, as defined in §180.1(n), are established for residues of the herbicide prometryn (2,4-bis(isopropylamino-6-methylthio-s- triazine) in or on the following raw agricultural commodity: [Table#4781]

Section 4(g)(2)(A) of FIFRA calls for the Agency to determine, after submission of relevant data concerning an active ingredient, whether products containing the active ingredient are eligible for reregistration. The Agency has previously identified and required the submission of the generic (i.e. active ingredient specific) data required to support reregistration of products containing prometryn. The Agency has completed its review of these generic data, and has determined that the data are sufficient to support reregistration of all products containing prometryn.

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. Prometryn 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 '88. Case No: 0467; Pesticide type: herbicide; Registration Standard Date: 03/20/87 PB87-184826; Case Status: RED Approved 09/95; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document ; Active ingredient (AI): prometryn; Data Call-in (DCI) Date(s): 09/30/91, 08/15,96; AI Status: OPP has completed a Reregistration Eligibility Decision (RED) for the case/AI.

A triazine derivative. Amines are chemical bases. They neutralize acids to form salts plus water. These acid-base reactions are exothermic. The amount of heat that is evolved per mole of amine in a neutralization is largely independent of the strength of the amine as a base. Amines may be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen is generated by amines in combination with strong reducing agents, such as hydrides.

Acute Tox. 4 (43.6%)

Acute Tox. 4 (100%)

Hazardous to the aquatic environment (Acute) - Category 1

Acute toxicity (Oral) - Category 4

If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped or safely confined. Use water in flooding quantities as fog. Solid streams of water may be ineffective. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use "alcohol" foam, carbon dioxide or dry chemical. /Triazine pesticides, liquid, NOS/

If material on fire or involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use water in flooding quantities as fog. Use "alcohol" foam, carbon dioxide or dry chemical. /Triazine pesticides, solid, NOS/

Environmental considerations- land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash, cement powder, or commercial sorbents. /Triazine pesticides, liquid, NOS/

Environmental considerations- water spill: Use natural barriers or oil spill control booms to limit spill travel. Remove trapped material with suction hoses. /Triazine pesticides, liquid, NOS/

Environmental considerations- air spill: Apply water spray or mist to knock down vapors. /Triazine pesticides, liquid, NOS/

Environmental considerations- land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. /Triazine pesticides, solid, NOS/

Environmental considerations- water spill: Use natural barriers or oil spill control booms to limit spill travel. Use natural deep water pockets, excavated lagoons, or sand bag barriers to trap material at bottom. Remove trapped material with suction hoses. /Triazine pesticides, solid, NOS/

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

Noncombustible containers should be crushed & buried under more than 40 cm of soil. /Herbicides/

Group I Containers: Combustible containers from organic or metallo-organic pesticides (except organic mercury, lead, cadmium, or arsenic compounds) should be disposed of in pesticide incinerators or in specified landfill sites. /Organic or metallo-organic pesticides/

Group II Containers: Noncombustible containers from organic or metallo-organic pesticides (except organic mercury, lead, cadmium, or arsenic compounds) must first be triple rinsed. Containers that are in good condition may be returned to the manufacturer or formulator of the pesticide product, or to a drum reconditioner for reuse with the same type of pesticide product, if such reuse is legal under Department of Transportation regulations (eg 49 CFR 173.28). Containers that are not to be reused should be punctured ... and transported to a scrap metal facility for recycling, disposal or burial in a designated landfill. /Organic or metallo-organic pesticides/

Only clean clothing ... should be worn & clothing should be changed daily ... Adequate sanitary facilities & washing water should be provided for workers to wash before meals. Smoking & consumption of alcoholic drinks before & during the handling of herbicides should be forbidden. Contaminated clothing should be removed immediately & a hot bath taken if possible. Personal hygiene should be encouraged. /Herbicides/

Follow manufacturer's instructions for cleaning/maintaining PPE. If no such instructions for washables, use detergent and hot water. Keep and wash PPE separately from other laundry. ... Users should remove clothing immediately if pesticide gets inside. Then wash thoroughly and put on clean clothing. Users should remove PPE immediately after handling this product. Wash the outside of gloves before removing. As soon as possible, wash thoroughly and change into clean clothing.

Users should wash hands before eating, drinking, chewing gum, using tobacco, or using the toilet.

Avoid contact with eyes, contact with skin, inhalation of dust & contamination of food & feed.

For more Preventive Measures (Complete) data for PROMETRYNE (12 total), please visit the HSDB record page.

Tolerances are established for residues of the herbicide prometryn (2,4-bis(isopropylamino)-6-methylthio-s-triazine) in or on the following raw agricultural commodities: [Table#4778]

Tolerances with regional registration, as defined in §180.1(n), are established for residues of the herbicide prometryn (2,4-bis(isopropylamino-6-methylthio-s- triazine) in or on the following raw agricultural commodity: [Table#4779]

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

Restricted-Entry Interval: Under the Worker Protection Standard (WPS), interim restricted entry intervals (REI) for all uses within the scope of the WPS are established on the basis of the acute toxicity of the active ingredient. ... For occupational end-use products containing prometryn as an active ingredient, the /EPA/ is establishing a 24-hour REI for celery and a 12-hour REI for all other uses of the product. ... The WPS establishes very specific restrictions on entry by workers to areas that remain under a restricted-entry interval if the entry involves contact with treated surfaces. Among those restrictions are a prohibition or routine entry to perform hand labor tasks and requirement that personal protective equipment to be worn. Personal protective equipment requirements for persons who must enter areas that remain under a restricted-entry interval are based on the toxicity concerns about the active ingredient. ... There are no special concerns about prometryn since the MOEs (margin of exposure) for most handlers are acceptable with the use of long-sleeve shirt, long pants, shoes socks, and chemical-resistant gloves. Therefore, for early entry following applications of prometryn, the Agency is establishing PPE for dermal protection based on the acute toxicity of the active ingredient. Since prometryn is classified as category III for eye irritation potential, protective eyewear is not required.

Application Restrictions: Do not apply this product in a way that will make contact with workers or other persons, either directly or through drift. Only protected handlers may be in the area during application. Engineering Controls: When handlers use closed systems (including water-soluble packets), enclosed cabs, or aircraft in a manner that meets the requirements listed in the Worker Protection Standard (WPS) for agricultural pesticides (40 CFR 170.240(d)(4-6), the handler PPE requirements may be reduced or modified as specified in the WPS.

Applicators and other handlers must wear: Long-sleeved shirt and long pants. Shoes plus socks. Chemical-resistant gloves, such as barrier laminate or viton. In addition, mixers and loaders supporting aerial applications must wear: Chemical-resistant apron. A dust/mist filtering respirator ... or an air-purifying respirator equipped with an R- or P-series filter ... /Caprol 4L/

Approved respirator. Chemical resistant apron when cleaning equipment, mixing, or loading. Chemical-resistant gloves. Long-sleeved shirt and long pants. Shoes plus socks.

For more Personal Protective Equipment (PPE) (Complete) data for PROMETRYNE (7 total), please visit the HSDB record page.

LC50 /Oncorhynchus mykiss/ (Rainbow trout) 2.5 mg/L/96 hr /Conditions of bioassay not specified in source examined/

LC50 Colinus virginianus (bobwhite quail) 16140 ppm in 5-7 day diet

LC50 Cyprinus carpio (Carp) 8 mg/L/96 hr at 20 °C; renewal

LC50 Cyprinus carpio (Carp) 9 mg/L/96 hr at 16 °C; renewal

For more Ecotoxicity Values (Complete) data for PROMETRYNE (17 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 39.4 to 3,473(2), indicate that prometryne is expected to have very high to slight mobility in soil(SRC). Volatilization of prometryne from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.2X10-8 atm-cu m/mole(SRC), derived from its vapor pressure, 1.24X10-6 mm Hg(3), and water solubility, 33 mg/L(4). In a model terrestrial system, no volatilization of the parent compound was seen from soil surfaces(7). However, estimated half-lives for volatilization of prometryne from soil range from 41 to 60 days for shallow to deep placement and varying water evaporation rates(5). The loss of prometryne applied to the surface of soil has also been observed to be relatively rapid in the first 30-40 days compared to the loss of prometryne which was incorporated into the soil(6). Prometryne is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(3). Half-lives for the biodegradation of prometryne in aerobic and anaerobic soil have been reported as 150 and 360 days, respectively(8).

AQUATIC FATE: Based on a classification scheme(1), Koc values of 39.4 to 3,473(2), indicate that prometryne may adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 1.2X10-8 atm-cu m/mole(SRC), derived from its vapor pressure, 1.24X10-6 mm Hg(4), and water solubility, 33 mg/L(5). According to a classification scheme(6), an estimated BCF of 48(SRC), from a log Kow of 3.5(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Half-lives for the biodegradation of prometryne in aerobic and anaerobic soil have been reported as 150 and 360 days, respectively(8), suggesting that biodegradation is not an important environmental fate process in water(SRC). Photochemical degradation half-lives of prometryne have a range of 4.6 hours(9) to 88 days (10).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), prometryne, which has a vapor pressure of 1.24X10-6 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase prometryne 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 10 hours(SRC), calculated from its rate constant of 3.8X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase prometryne may be removed from the air by wet or dry deposition(SRC). Prometryne does contain chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight(4).

Prometryn was first registered in the United States in 1964 as a herbicide for the control of weeds in cotton, celery, pigeon peas, and dill. A Registration Standard was issued in March 1987 (NTIS# PB87-184826) ... In studies using laboratory animals, prometryn technical has been shown to be slightly to practically non-toxic for oral, dermal, inhalation and has been placed in Tox Category III (next to lowest in the four categories) for these. Additionally, pertaining to acute eye and dermal irritation, prometryn technical is considered to be slight to practically non toxic, respectively and has been categorized as being in Categories III and IV for these. Prometryn is not considered a sentizer. In a subchronic 28-day feeding study using rats showed that macroscopic and microscopic pathological findings appeared in the high dose animals and were limited to the G.I. tract along with clinical signs and marked decreases in body weights were also seen in these animals. In a 21- day dermal toxicity study with rabbits, no local or systemic toxicity was observed at the highest dose levels (1000 mg/kg/day). In three chronic toxicity/carcinogenicity studies with mice, rats and dogs showed that prometryn was not oncogenic. Prometryn was classified as a Group E Carcinogen (no evidence of human carcinogenic potential) because prometryn did not alter the spontaneous tumor profile for the strains of mice and rats tested. The dog study, however, was not considered because, even though there were some effects, under the conditions of the study, the effects were not oncogenic. A developmental toxicity study with rats showed the highest dose level caused maternal and developmental toxicity. In another study also conducted with rabbits resulted in effects at the highest dose level, including increased abortions and decrease in body weight parameters. A 2-generation reproductive study with rats showed effects at the highest dose level including decrease in body weight and corresponding food consumption. Nevertheless, the statistically significant decrease in pup body weight (also at the high dose level) was considered to be toxicologically significant because of its potential negative impact on postnatally developing systems such as the neuro- and immune systems. In four mutagenicity studies (ames samonella test, chromosomal aberration, bacterial DNA repair, and unscheduled DNA synthesis test) prometryn was found to be negative. A series of (radiolabeled) general metabolism studies with rats showed the greatest distribution of prometryn first in the blood followed by the spleen and then in the lungs. People may be exposed to residues of prometryn through the diet. Tolerances or maximum residue limits have been established for a variety of crop and animal commodities...

/AQUATIC SPECIES/ Prometryne in aquatic environment had adverse effect on its population, especially fish. The median lethal effect on carp of exposure for 1-4 days was 14-20 mg/cu dm.

/AQUATIC SPECIES/ The toxicity of prometryn to fish was investigated. The 30 day toxicity threshold was 0.1 mg/L for rainbow trout. Minnow & Danio rerio males were more susceptible than females. Prometryn showed gonadotoxicity in both male & female minnows. At 3 mg/L the hemoglobin and erythrocyte level decr in fish blood within 7 days. Four im injections of 250 mg prometryn/kg caused no poisoning in carp; but one im injection of 500 mg prometryn/kg did cause poisoning indicating a absence of accumulation in the fish. In carp poisoned by 25 mg/L for 6 hr coordination returned after 40 min in clean water, the hemoglobin level returned to normal within 5 days, & erythrocyte level returned to normal within 10 days.

/AQUATIC SPECIES/ The effects of 40 herbicides with nine modes of action on the green alga Raphidocelis subcapitata were studied by 96-hr acute toxicity tests. Results showed that the EC50 of the herbicides with respect to the photosynthetic processes of R. subcapitata ranged from 0.0007 to 4.2286 mg/L. Photosynthesis was the process of the green alga most sensitive to the tested herbicides. The most toxic herbicides were atrazine, ametryme, simazine, prometryne, cyanazine, isoproturon, chlorotoluron, diuron, methabenzthiazuron, and paraquat. The EC50 of the protoporphyrinogen oxidase inhibitor oxadiargyl, which was the parameter least sensitive to the herbicides tested in this study, was 42.5 mg/L. The descending order of the average acute toxicity to R. subcapitata of herbicides with regard to the nine modes of action was as follows: photosynthetic process>cell division>lipid synthesis, acetyl-coenzyme A carboxylase>acetolactate synthase> 5-enolpyruvyl-shikimate-3-phosphate synthase, glutamine synthase, hormone synthesis>protoporphyrinogen oxidase.

/AQUATIC SPECIES/ Planktonic green algae (Ankistrodesmus falcatus) and guppies (Poecilia reticulata) were used to test the toxicity of prometryne to aquatic organisms. It was highly toxic to guppies and acted as a strong photosynthesis poison to algae.

/AQUATIC SPECIES/ The effect of fluometuron, prometryne, ametryne, and diuron on growth of floating hydrophytes, Lemna major L. (Spirodela polyrrhiza) and Lemna perpusilla Torr. were studied. Concentrations of the herbicides used ranged from 2 X 10-5 M to 1 X 10-8 M. Fluometuron was the least toxic herbicide to both L. major L. and persilla Torr. Diuron was the most toxic to L. major at a concentration of 1 X 10-6 M. The other two herbicides were about equally toxic to L. perpusilla. Concentrations required to cause 50% growth inhibition of L. major were: fluometuron, 2.6 N 10-6 M; prometryne 3.5 X 10-7 M; ametryne, 2.3 X 10-7 M; and diuron, 1. 75 X 10 SUP- 7M. Concentrations which inhibitied 50% growth of L. perpusilla were: fluometuron, 2.05 X 10-6 M; diuron, 6.4 X 10-8 M; prometryne, 5.4 X 10-8 M; and amytryne, 4.6 X 10-8 M. ...

Prometryn

Hematologic

4 x 10 ^-3 mg/kg-day

Preliminary medical exam to detect chronic diseases of CNS, liver, heart, kidneys, lungs & skin, as well as endocrinological or immunological disturbances, should ... /protect/ susceptible individuals. ... Periodical medical exam of internal organs, skin & eyes is important to avoid chronic occupational intoxications. It should include lab tests & patch tests if necessary. /Herbicides/

Koc values of 300 and 600 were measured for prometryne in soil at a pH of 7 and 5, respectively(1). Koc values of 200, 320, 808, and 1000 were measured in batch adsorption experiments at 10 °C using river sediment from 4 different locations on the same river(2). According to a classification scheme(3), these Koc values suggest that prometryne is expected to have slight to very high mobility in soil(SRC).

Koc values for various soils. [Table#4782]

Prometryne exhibited low mobility in soil thin-layer chromatography and soil-column leaching experiments with silty clay loam and clay loam soils in which the Rf range for prometryne was 0.10-0.29(1). Prometryne was applied at 2 kg a.i./ha along with diazinon, and measurements were made to determine the extent of movement in orchard soils(2). By day 14, a slight movement of prometryne into the 5 to 30 cm zone, due to previous rainfall, was seen(2). Prometryne has a pKa of 4.1(3); Koc values for this compound are expected to increase with lower pH as the protonated species is more readily sorbed to exchange sites in the soil(8). A PLP (Pesticide Leaching Potential) Index number of 46 to 51 on a scale from 0 (no leaching potential) to 100 (max leaching potential) was calculated for prometryne(4). Prometryne had low mobility relative to 12 other pesticides in experiments testing for lateral movement through soil(5). Of 122 values sited in literature the mean Kd is 7.00 making prometryne a weak base(6). Adsorption of the s-triazine herbicides is highly dependent upon the types and amounts of organic matter and clay in the soil(7). Adsorption of prometryne to soil follows an L-1 type isotherm(8).

Tolerances are established for residues of the herbicide prometryn (2,4-bis(isopropylamino)-6-methylthio-s-triazine) in or on the following raw agricultural commodities: [Table#4780]

Tolerances with regional registration, as defined in §180.1(n), are established for residues of the herbicide prometryn (2,4-bis(isopropylamino-6-methylthio-s- triazine) in or on the following raw agricultural commodity: [Table#4781]

Section 4(g)(2)(A) of FIFRA calls for the Agency to determine, after submission of relevant data concerning an active ingredient, whether products containing the active ingredient are eligible for reregistration. The Agency has previously identified and required the submission of the generic (i.e. active ingredient specific) data required to support reregistration of products containing prometryn. The Agency has completed its review of these generic data, and has determined that the data are sufficient to support reregistration of all products containing prometryn.

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. Prometryn 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 '88. Case No: 0467; Pesticide type: herbicide; Registration Standard Date: 03/20/87 PB87-184826; Case Status: RED Approved 09/95; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document ; Active ingredient (AI): prometryn; Data Call-in (DCI) Date(s): 09/30/91, 08/15,96; AI Status: OPP has completed a Reregistration Eligibility Decision (RED) for the case/AI.

... Their chief mode of action appears to involve carbohydrate metabolism. The chlorinated s-triazines inhibit starch accumulation by blocking the prodn of sugars. Similar behavior has been shown for the methoxy & methylthio-s-triazines. It has been reported that the s-triazines affect the tricarboxylic acid cycle with activation of phospho-phenyl pyruvate-carboxylase causing the disappearance of sucrose & glyceric acid with the formation of aspartic & malic acids. /S-triazines/

Inhibits photolysis of water in the photosynthetic process. Also inhibits oxidative phosphorylation /in plants/

Primary mode of action /in plants/ is inhibition of photolysis of water in photosynthetic process. Prometryn has been shown to have other biol effects, such as inhibition of oxidative phosphorylation.

Mechanism of action/in target species/: inhibits electron transport.

For more Mechanism of Action (Complete) data for PROMETRYNE (7 total), please visit the HSDB record page.

In addition to CH3S- displacement by -OH, in rats and rabbits treated with prometryne CH3S-group is dealkylated without sulfur oxidation followed by oxidative coupling to disulfide.

... Hydroxypropazine & hydroxyatrazine were detected when cotton, soybeans, peanuts, & carrots were treated with (14)C-ring-labeled prometryn ... Supporting evidence for methylthio group cleavage came from studies with (14)CH3-labeled prometryn in peas where moderate amount of (14)carbon dioxide were liberated.

Rats & rabbits fed prometryne excreted 2-mercapto-4-amino-6-isopropylamino-s-triazine & bis(2-amino-4-isopropylamino-s-triazinyl-6-yl)disulfide. Mono- & di-dealkylated prometryne analogs were also observed. 8 day old pea plants were exposed ... & harvested 8 days later. Several metab pathways were indicated. In one, the side chain of prometryn was metab and 2-hydroxy-4-amino-6-isopropylamino-s-triazine was identified. In the other, the methylthio group was oxidized to sulfone which readily hydrolyzes to hydroxy analog. Chromatography indicated presence of sulfoxide & hydroxy analogs.

Prometryn in rats and rabbits is converted to both the thio ... /deriv/, & the corresponding disulfide, together with a number of other urinary metabolites.

For more Metabolism/Metabolites (Complete) data for PROMETRYNE (8 total), please visit the HSDB record page.

Mono- & didealkylated parent compounds ... were identified in urine of rats & rabbits after application of several hundred mg/kg of nonlabeled simazine, atrazine, propazine, prometone and prometryn.

In the rat, most of the administered prometryn is excreted within 48 hours in urine and feces.

When given by oral gavage to rats as a (14)C-labeled material, 2,4-bis(isopropylamino)-6-methylthio-s-triazine was detected in both urine and feces. The chemical was absorbed and rapidly excreted. Limited transfer to the milk of lactating goats or to the eggs of laying hens was reported. The triazines, including prometryne, are generally well-absorbed by the mammalian gut and probably across the skin. The breakdown of prometryne is not adequately understood ... No detectable residues of prometryne or its metabolites were found in the muscle, fat, blood, liver, kidney, or other organs of sheep and cattle fed up to 100 ppm for 4 weeks. However, prometryne or its breakdown products were found in whole milk samples taken from cows that were fed up to 100 ppm in their diets for 21 days.

They are efficiently absorbed from intestine, and presumably there is some absorption across the skin and lung. /Urea-, uracil- and triazine-based herbicides/

Used as pre- or post-emergence herbicide for control of annual grasses and broad-leaved weeds in cotton, peanuts, vegetables, other crops, and forestry; [HSDB]

Farming (Pesticides) [Category: Industry]

For prometryn (USEPA/OPP Pesticide Code: 080805) 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./

Substituted thiomethyl triazine herbicide

Herbicide

For most annual grasses, broadleaf weeds in cotton and celery. Applied to cotton broadcast or in band as preplant incorporated, preemergence.

(1975) 9.53X10+6 G (CONSUMPTION)

(1978) 9.53X10+6 G (CONSUMPTION)

Percent of Pesticide Applied to Crop: (1) Cotton, approximately 97 percent (1,100,000 - 1,500,000 lb active ingredient), of total domestic usage of prometryn; (2) celery, approximately 3 percent (31,000-37,000 lb active ingredient) of total domestic usage of prometryn

Percentage of Various U.S. Crops Treated with Prometryn, 1990-1992: Celery, 56-83%, 15-25 lb a.i.; Cotton, 14-21%, 1,100-1,800 lb a.i.; Other, 20-25 lb a.i.

Prometryne: 1807X10+3, 1192X10+3, and 656X10+3 lbs ai/year in 1989, 1982, and 1976, respectively.

Reaction of 2-chloro-4,6-bis(isopropylamino)-s-triazine with sodium methyl mercaptide.

... Reacting propazine with methyl mercaptan in presence of 1 equiv of sodium hydroxide or by reacting 2-mercapto-4,6-bis(isopropyl-amino)-s-triazine with methylating agent in presence of sodium hydroxide.

Prometryn is produced by reaction of propazine with methylmercaptan in the presence of sodium hydroxide, followed by treatment with dimethyl sulfate.

PREPARATION: H GYSIN, E KNUSLI, CH 337019; EIDEM, US 2909420 (BOTH 1959 TO GEIGY)

CAPAROL 4L HERBICIDE Active Ingredient 44.4% Prometryn

COTTON-PRO Active Ingredient 45.41% Prometryn

GOWAN PROMETRYNE 4L Active Ingredient 44.4% Prometryn

PROMETRYN TECHNICAL Active Ingredient 97.0% Prometryn

For more Formulations/Preparations (Complete) data for PROMETRYNE (11 total), please visit the HSDB record page.

The WHO Recommended Classification of Pesticides by Hazard identifies Prometryne (technical grade) as unlikely to present an acute hazard in normal use; Main Use: herbicide.

The 1992 Worker Protection Standard for Agricultural Pesticides (WPS) established certain worker-protection requirements (personal protective equipment, restricted entry intervals, etc.) to be specified on the label of all products that contain uses within the scope of the WPS. Uses within the scope of the WPS include all commercial (non-homeowner) and research uses on farms, forests, nurseries, and greenhouses to produce agricultural plants (including food, feed, and fiber plants, trees, turf grass, flowers, shrubs, ornamentals, and seedlings). Uses within scope include not only uses on plants, but also uses on the soil or planting medium the plants are (or will be) grown in. At this time all of the registered uses of prometryn are within the scope of the Worker Protection Standard (WPS). ... There are no registered products containing prometryn that are intended for homeowner use.

Crop rotation restrictions or precautions usually are not required because of the shorter residual life & also because of the much greater safety margin which many sensitive plants have to methylthiotriazines compared to chloro or methoxytriazines.

Applications may be made preemergence, post directed, and at layby in cotton. Preemergence applications in cotton can be incorp in AZ & CA. Postemergence applications are recommended for celery. Prometryn has considerable contact activity, therefore, postemergence treatments must be directed, exept in celery. Rates: 1.34 to 3.08 kg/ha (1.20-2.75 lb/acre) are usually required for selective preemergence of layby weed control, while rates of 0.54 to 0.72 kg/ha (0.48-0.64 lb/acre) are common for postdirected sprays to control emerged seedling weeds. Usual carrier: water at 187 to 374 L/ha (20 to 40 gpa) is the usual carrier for uniform application. Agitation in the spray tank is necessary to keep the chemical in suspension. ... Compatible with most other pesticides & fertilizers when used at normal rates. ... Glassware and spray equipment may be cleaned by washing with water, although prometryn should not be allowed to dry out or stand in sprayers.

For more General Manufacturing Information (Complete) data for PROMETRYNE (8 total), please visit the HSDB record page.