Desmetryn

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.

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.