데스메트린

Herbicides

Active substance -> EU Pesticides database: Not approved

Pesticides -> Herbicides, Triazine

Pesticide (Desmetryn) -> USDA PDB

log Kow = 2.38

2.79

Crystalline

White powder

White to beige powder

Solubilities in organic solvents at 20 °C. [Table#3504]

In water, 58 mg/L at 20 °C

0.000001 [mmHg]

9.98X10-7 mm Hg at 20 °C

Warning

H302: Harmful if swallowed [Warning Acute toxicity, oral]

P264, P270, P273, P280, P301+P317, P302+P352, P317, P321, P330, P362+P364, P391, and P501 (click each P-code to see the statement)

Warning

H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]

P264, P270, P273, P280, P301+P317, P302+P352, P317, P321, P330, P362+P364, P391, and P501 (click each P-code to see the statement)

The triazine herbicides disrupt photosynthesis in plants; they are not highly toxic in mammals; In lethal-dose animal studies, adverse effects included CNS disturbance, decreased hemoglobin, and liver and kidney injury; [HSDB] For the triazine herbicides, systemic toxicity unlikely unless large amounts are ingested; May cause irritation; [EPA Pesticides, p. 121]

The major hazards encountered in the use and handling of desmetryne 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 a 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 desmetryne does not ignite easily, it may burn with the production of irritating and poisonous gases. For fires involving desmetryne, extinguish with dry chemical, CO2, Halon, water spray, fog, or standard foam. Desmetryne may be shipped via air, rail, road, and water, in containers bearing the label "Poison". Small dry spills of desmetryne 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 ametryne from entering water sources and sewers. Before implementing land disposal of desmetryne, consult with regulatory agencies for guidance.

Acute Tox. 4 (100%)

Acute toxicity - category 4

Acute Tox. 4 *

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

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./ 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/

Avoid skin & eye contact. Prevent drift.

Only clean clothing ... should be worn & clothing should be changed daily ... Adequate sanitary facilites & 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/

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at end of shift, but should remain at employee's place of work for cleaning.

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. /Triazine pesticide, solid, NOS/

Personnel protection: Avoid breathing dusts, and fumes from burning material. Keep upwind. Avoid bodily contact with the material. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water. ... If contact with the material anticipated, wear appropriate chemical protective clothing /Triazine pesticide, solid, NOS/

LC50; Species: Cyprinus carpio (Common carp); Conditions: freshwater, static; Concentration: 10 mg/L for 48 hr

LC50; Species: Oryzias latipes (Medaka high-eyes); Conditions: freshwater, static; Concentration: 10 mg/L for 48 hr

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 470(SRC), determined from a log Kow of 2.38(2) and a regression-derived equation(3), indicates that desmetryne is expected to have moderate mobility in soil(SRC). Volatilization of desmetryne from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 4.8X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, 9.98X10-7 mm Hg(2), and water solubility, 580 mg/L(4). Desmetryne is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(2). Biodegradation data were not available(SRC, 2007).

TERRESTRIAL FATE: Degradation involves oxidation of the methylthio group to sulfoxide & sulfone, hydrolysis with introduction of 2-hydroxy group, dealkylation at the substituted amino groups, cleavage of the amine moiety, & ring opening. Duration of residual activity in soil is about 3 mo.

TERRESTRIAL FATE: IN SOIL ... THE AMINE SIDE CHAINS ARE DEALKYLATED TO A CONSIDERABLE DEGREE, ULTIMATELY TO THE HYDROXIDE ION. THE CONVERSION OF DIALKYLAMINE TO MONOALKYLAMINE IS ACTIVATING STEP. /1,3,5-TRIAZINES/

TERRESTRIAL FATE: THE PERSISTENCE OF DESMETRYNE (1.5-3.0 KG/HA) IN DIFFERENT SOILS WAS STUDIED. DESMETRYNE DISAPPEARED MORE RAPIDLY FROM SANDY SOIL THAN FROM CLAY SOIL & NONE OF THE CMPD WAS DETECTED 1 YR AFTER APPLICATION.

For more Environmental Fate (Complete) data for DESMETRYNE (7 total), please visit the HSDB record page.

/AQUATIC SPECIES/ Toxic to fish.

/OTHER TERRESTRIAL SPECIES/ Not toxic to bees.

The Koc of desmetryne is estimated as 470(SRC), using a log Kow of 2.38(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that desmetryne is expected to have moderate mobility in soil. Evidence has been reported that indicates that the basicity of s-triazine herbicides, such as desmetryne, is not the main factor governing adsorption to soil humic acids(4). It has been shown that the ability of s-triazine herbicides to act as electron donors to electron acceptor quinone-like units of humic acids plays an important role in the adsorption(5).

Adsorption of triazines through an exchange process to organic matter & clay minerals is dependent on the pH of the soln & the acidity of the adsorbent surface. Hydrogen bonding & hydrophobic bonding are other mechanisms by which soil organic matter adsorbs triazine herbicides, especially at higher pH levels. ... Transfer from soil to water occurs in soln & in sediments. /Triazine herbicides/

/OTHER TOXICITY INFORMATION/ Human serum albumin (HSA) serves as a carrier protein to transport triazine herbicides to molecular targets. In this paper, a theoretical treatment was developed to describe the HAS-triazine herbicides association. A determination of the association constant, K, as well as the degree of complexation n subc (the percent of complex guest) was carried out. Enthalpy-entropy compensation was also analyzed in relation to this mathematical model to confirm the herbicide complexation behavior with HSA. The role of the sodium cation (Na+) on this association was investigated. It was expected that the sodium ion would act on the herbicide-HSA association process by modifying the surface tension of the bulk solvent and increase the K and n subc values. The results showed that for patients who suffer from Na+ desequilibrium, the triazine - HSA binding would change and as well the toxicological effect of these herbicides.

Desmetryne's production may result in its release to the environment through various waste streams; its use as a herbicide(1) will result in its direct release to the environment. Desmetryne is not sold in the USA, but is used in Europe(2) and China(3) on various crops.

An estimated BCF of 6.5 was calculated in fish for desmetryne(SRC), using a log Kow of 2.38(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Henry's Law constant for desmetryne is estimated as 4.8X10-10 atm-cu m/mole(SRC) derived from its vapor pressure, 9.98X10-7 mm Hg(1), and water solubility, 580 mg/L(2). This Henry's Law constant indicates that desmetryne is expected to be essentially nonvolatile from water surfaces(3). Desmetryne is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

/LABORATORY ANIMALS: Acute Exposure/ When applied to skin of rabbits, Semeron causes mild local irritating effect. No general resorptive action was detected.

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ Toxicological experiments were performed with Semeron (desmetryne) on rats, mice, and rabbits. The /oral/ LD50 value, determined for rats and mice in acute poisoning tests, is 2,000 and 700 mg/kg, respectively. Prolonged administration of 1/10 and 1/20 LD50 doses produced poisoning symptoms: disturbances in the function of the central nervous system; reduced hemoglobin, leukocyte and neutrophil counts in the blood; reduced hippuric acid level in the urine; pronounced venous congestion of parenchymal organs and the cerebrum and cerebral membranes; hemorrhages of the mucosa; and dystrophic degenerations in the liver, kidney, and cerebral ganglia. Slight local irritation, but no poisoning symptoms, with skin application of single or repeated 500 mg/kg doses was observed on rabbits. Weakly expressed cumulative properties and low toxicity were determined. The recommended maximum allowable workplace concentration of desmetryne is 2 mg/cu m.

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ In 90 day trials no effect level was: for rats 200 mg/kg diet (13 mg/kg daily); for dogs 200 mg/kg (6.6 mg/kg daily).

/GENOTOXICITY/ Bacillus subtilis MA5 DNA damage assay negative

For more Non-Human Toxicity Excerpts (Complete) data for DESMETRYNE (7 total), please visit the HSDB record page.

Herbicidal action is due to inhibition of Hill reaction necessary for plant respiration. The resistance of a plant to a particular triazine depends on its ability to detoxify the cmpd under field conditions. /Prometon/

Since chlorosis is the first sign of the effect of triazines on plants, interference with carbon dioxide assimilation & sugar formation can be expected. Studies showing that Hill reaction is inhibited confirmed this. /Triazines/

... 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/

Inhibition of photosynthesis by disruption of light reactions and blockade of electron transport is the mechanism of action of the 1,3,5-triazine herbicides. /1,3,5-Triazines, from table/

The influence of some s-triazine herbicides on acid phosphatase and phosphodiesterase from corn (Zea mays) roots were investigated. Terbutryn stimulated both phosphatases, whereas prometryn stimulated only the phosphodiesterase. Atrazine, desmetryn, prometon, and simazine inhibited acid phosphatase. No effect was exerted by ametryn. The enzyme assays and the kinetic parameters demonstrated that the interferences observed were due to an action on the synthesis of one or both enzymes rather than on the enzyme reaction. The types of the N-alkyl and the chlorine-substituent groups in the structures of the s-triazines tested appear important in determining the degree if the interference.

All of these herbicides /methoxy or methylthio substituted triazine herbicides/ are rapidly absorbed and metabolized when ingested; amine dealkylation and side chain oxidation are the predominant detoxification reactions. The mercapto derivatives of triazine may also undergo sulfoxidation followed by reaction with hepatic glutathione to yield mercapturic acid derivatives. /s-Triazines/

... /Desmetryne is/ absorbed by leaves & roots ... /& translocated/ acropetally through xylem, & ... /accumulated/ in apical meristems.

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 post-emergence herbicide for control of broad-leaved and grassy weeds; Not marketed in the US; WHO has classified this pesticide as believed to be obsolete or discontinued; [HSDB]

Farming (Pesticides) [Category: Industry]

Selective post-emergence herbicide effective for control of chenopodium album and other broadleaved and grassy weeds in most Brassica crops /not marketed in the USA/

Post emergence herbicide (superseded)

The WHO Recommended Classification of Pesticides by Hazard identifies Desmetryne (technical grade) as an active ingredient believed to be obsolete or discontinued for use as a pesticide.

Not marketed in the US

It was introduced in 1964 by Ciba-Geigy LTD. Its herbicidal properties were described by Baker C et al, Weed Res 3, 109, 1963; Elliott JG and Cox TI, Proc 6th Brit Weed Control Conf, 1962. Swiss patent 337,019; British patent 814,948.

Compatible with other wettable powder herbicides.

The reactions of four sulfur containing s-triazines (prometryne, terbutryne, ametryne and desmetryne) with hypochlorous acid (HClO) and chlorine dioxide (ClO2) have been investigated using an 11 ppm/3 ppm oxidant/herbicide ratio. The main objective of the study was the identification of by-products. Additionally, to study the effect of oxidant concentration on the reaction rate, two more oxidant/herbicide ratios (3 ppm/3 ppb and 11 ppb/3 ppb) have been investigated only for prometryne. Oxidation reactions were monitored by high performance liquid chromatography (HPLC), while, the identification of by-products was initially carried out by low resolution HPLC-mass spectrometry (HPLC-MS) and confirmed by accurate mass measurement. Under the experimental conditions (T = 20 degC, pH = 8, reaction TIME = 48 hr), the results indicate that all the investigated triazines react in the same way with each oxidant. The reactions with HClO occur much faster than those with ClO2 and give rise to three identified oxidation by-products: the sulfoxide, the sulfone and the sulfone's hydrolysis product. The reactions with ClO2, instead, give rise to a sole oxidation by-product: the sulfoxide. With both oxidants, as expected, the lower the oxidant concentration the slower the oxidation rate.