Dinitramine

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.

For several good reasons, all of the herbicides mentioned in this chapter /such as dinitramine/ should be handled and applied only with full attention to safety measures that minimize personal contact. Many formulations contain adjuvants (stabilizers, penetrants, surfactants) that may have significant irritating and toxic effects. A number of premixed formulations contain two or more active ingredients; the companion pesticides may be more toxic than the principal herbicide. Good hygienic practice should not be disregarded just because a pesticide is reported to have a high LD50 in laboratory rodents.

The emulsificable concentrate ... should be kept away from heat or open flame.

Cleaning glassware and equipment: Glassware: rinse with water and detergent then with acetone. Equipment: flush thoroughly with water and detergent.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

LC50; Species: Oncorhynchus kisutch (Coho salmon, weight 0.9 g); Conditions: freshwater, flow through, 12 °C, pH 7.5; Concentration: 1850 ug/L for 96 hr (95% confidence interval: 1568-2181 ug/L) /technical material, 99.2% purity/

LC50 Oncorhynchus kisutch (Coho salmon) 600 ug/L/96 hr at 12 °C, 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, 99.2%.

LC50 Salmo trutta (Brown trout) 590 ug/L/96 hr at 12 °C, 0.7 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, 99.2%.

LC50 Salvelinus mamaycush (Lake trout) 920 ug/L/96 hr at 12 °C, 0.6 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, 99.2%.

For more Ecotoxicity Values (Complete) data for DINITRAMINE (20 total), please visit the HSDB record page.

TERRESTRIAL FATE:Based on a classification scheme(1), a Koc value of 4000, determined from multiple soil adsorption studies(2), indicates that dinitramine is expected to have slight mobility in soil(SRC). Leaching studies have demonstrated that dinitramine does not leach in soil(3-5). Volatilization of dinitramine from moist soil surfaces is expected be an important fate process(SRC) based upon soil volatility studies(6) that measured vapor losses of 1.4 to 5% over a 3-hr period from various moist soils under varying conditions and temperatures. Dinitroaniline herbicides (such as dinitramine) should be incorporated into soil within a few hours to 24 hours to prevent loss through evaporation which reduces herbicidal activity(4,7). Dinitramine has been shown to photodecompose on soil surfaces exposed to sunlight(7,8), and incorporation into soil will reduce losses due to sunlight(7). Dinitramine is metabolized by soil micro-organisms(4,5,7). Degradation of the dinitroaniline herbicides (including dinitramine) in soils is primarily by microbiological processes(7); fungi appear to be the major microbial species involved(7); degradation occurs more rapidly under moist conditions than dry conditions and more rapidly in warm soil than cool soil(7). Dinitramine metabolism has been observed to occur faster in anaerobic soil compared to aerobic soil(4). A variety of field dissipation studies have measured dinitramine half-lives ranging from 10 to 150 days with an average recommended half-life of 30 days(2). A typical soil half-life of 10-66 days has also been reported(5) with less than 10% of applied dinitramine remaining in most soils 90-120 days after application.

AQUATIC FATE: Based on a classification scheme(1), a Koc value of 4000, determined from multiple soil adsorption studies(2), indicates that dinitramine is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 1.39X10-6 atm-cu m/mole(SRC), derived from its vapor pressure, 3.60X10-6 mm Hg(4), and water solubility, 1.1 mg/l(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 47 and 350, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column; the estimated volatilization half-life from a model pond is greater than 10 years if adsorption is considered(6). According to a classification scheme(7), an estimated BCF of 408(SRC), from an estimated log Kow(4), a 3-day BCF of 235 measured in Gambusia fish, and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is high(SRC). Aqueous degradation studies(10), conducted over a several month period, have shown that dinitramine does not degrade via aqueous hydrolysis at pH 5, 7 or 9(10). Dinitramine absorbs light in the environmental spectrum(11); in aqueous solutions, dinitramine has been shown to photodegrade rapidly when exposed to direct sunlight with a half-life of 10 minutes to a few hours depending on conditions(10); therefore, photodegradation may be an important removal process in aquatic media(SRC). Dinitramine is metabolized by soil micro-organisms under both aerobic and anaerobic conditions(4,12,13); therefore, dinitramine is expected to be susceptible to biodegradation in natural waters(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dinitramine, which has a measured vapor pressure of 3.60X10-6 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase dinitramine 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 about 22 hours(SRC), calculated from its rate constant of 1.77X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase dinitramine may be removed from the air by wet or dry deposition(SRC). Dinitramine absorbs light in the environmental spectrum(4) and has been observed to degrade readily when exposed to sunlight(5); therefore, direct photolysis may contribute to the removal of dinitramine from the atmosphere(SRC).

Based upon a variety of measured Koc values in different soils (range of 115 to 34,400), dinitramine has a recommended Koc of 4000(1). According to a classification scheme(2), this Koc value suggests that dinitramine is expected to have slight mobility in soil. In adsorption studies using a Plano silt loam soil(3), dinitramine did not leach more than 4 mm over a 17-day observation period. No leaching was detected for dinitramine or six other dinitroaniline herbicides during a 1-year period in which 145 cm of rainfall and irrigation water entered sandy loam plots(4); these dinitroaniline herbicides were essentially immobile in soil(4). Dinitramine is reported to be strongly adsorbed on soil with no leaching(5).

AEROBIC: Degradation of dinitroaniline herbicides in soil (including dinitramine) appears to be primarily by soil micro-organisms (1,2); little or no degradation of dinitroaniline herbicides has been reported for sterilized soils via autoclaving or potassium azide treatment(2). Aerobic degradation of dinitramine proceeds through a dealkylation step followed by progressive reduction of the nitro groups (2-4); cyclization of a reduced nitro group (an amino group) with alkyl groups forms benzimidazoles(2,4). Degradation is reported to be faster under moist soil conditions compared to dry conditions and faster at higher temperatures than lower temperatures(1,2).

ANAEROBIC: Dinitramine has been observed to metabolize faster in anaerobic soil compared to aerobic soil(1,2). Anaerobic degradation of dinitroaniline herbicides proceeds through reduction followed by dealkylation(2).

An estimated BCF of 408 was calculated in fish for dinitramine(SRC), using an experimental log Kow of 4.30(1) and a regression-derived equation(2). An aquatic ecosystem study using Gambusia fish and a 3-day exposure period in the dark, determined a dinitramine BCF value of 235(3); the BCF value under sunlight conditions was 83; the lower BCF value in sunlight was thought to be the result of dinitramine photodegradation in sunlight. According to a classification scheme(4), BCF values of 235 and 408 suggest the potential for bioconcentration in aquatic organisms is high(SRC), provided the compound is not metabolized by the organism(SRC).

The Henry's Law constant for dinitramine is estimated as 1.39X10-6 atm-cu m/mole(SRC) derived from its vapor pressure, 3.60X10-6 mm Hg(1), and water solubility, 1.1 mg/L(2). This Henry's Law constant indicates that dinitramine is expected to volatilize from water surfaces(3). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(3) is estimated as 47 days(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(3) is estimated as 350 days(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The estimated volatilization half-life from a model pond is greater than 10 years if adsorption is considered(4). The volatility of dinitramine and 10 other dinitroaniline was measured over a 3-hr period from moist soils under laboratory conditions at temperatures ranging from 30 to 50 °C and an air-flow rate of 50ml/min(5); in Lakeland sand soil (7.0% soil moisture), dinitramine vapor losses were approximately 1.5, 2.1 and 5.5% at 30, 40 and 50 °C, respectively; in Lakeland sand soil (15.0% soil moisture), dinitramine vapor losses were approximately 1.4, 2.7 and 2.7% at 30, 40 and 50 °C, respectively; in Hagerstown clay loam soil (25.8% moisture) and Littleton silt loam (25% moisture at field capacity), dinitramine vapor losses at 50 °C were 3.0 and 1.5%, respectively.

The rate constant for the vapor-phase reaction of dinitramine with photochemically-produced hydroxyl radicals has been estimated as 1.77X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 22 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Dinitramine is not expected to undergo aqueous hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2); no decomposition was observed for aqueous solutions of dinitramine at pH values of 5, 7 and 9 when stored in the dark for several months(3). Sunlight irradiation of dilute (1 ppm) aqueous solutions of dinitramine resulted in rapid photodecomposition(3); exposure to midday May sunlight in southern CA caused degradation with a half-life of approximately 10 minutes(3); sunlight photolysis was also rapid in natural water from the Santa Ana River and Pacific Ocean; photolytic degradation of solid dinitramine adsorbed on sand was also observed (reduction of 1 ppm to 0.16 ppm over 4-hr exposure to midday sunlight(3). Photodecomposition studies using dinitramine adsorbed to dry Hagerstown clay loam soil and exposed to direct sunlight over a 7-day period observed a 72.3% photodecomposition of initial dinitramine(4).

During photodegradation, an N-alkyl group is cyclized with a less hindered nitrogen atom at the 4-position (from an amino group) to form benzimidazoles.

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. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA, as amended in 1988, were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern and List D pesticides of less concern. N3,N3-Diethyl-2,4-dinitro-6-(trifluoromethyl)-1,3-benzenediamine is found on List B. Case No: 2185; Pesticide type: herbicide; 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): N3,N3-Diethyl-2,4-dinitro-6-(trifluoromethyl)-1,3-benzenediamine; AI Status: The active ingredient is no longer contained in any registered pesticide products ... "cancelled."