2-Ethylhexyl (2,4-dichlorophenoxy)acetate

333.25008

333.25

217-673-3

3082|2765

DTXSID4034235

Golden yellow, non viscous liquid

35.5

5.78 at 25 deg C

1.148 at 20 deg C

<-37 deg C

>300 deg C (decomp)

171 deg C (Cleveland open cup)

1.5810 (estimate)

In water, 0.086 mg/L at 25 deg C

47.9 mPa /3.59X10-4 mm Hg/ at 25 deg C (Calculated)

Sweet slightly pungent odor

Henry's Law constant = 1.8 Pa cu m/mol (1.8X10-5 atm-cu m/mol)

In water, 0.0324 mg/L|Hydroxyl radical reaction rate constant = 15X10-12 cu cm/molec-sec at 25 °C /Estimated/

No rapid reaction with air. No rapid reaction with water.

Esters, Sulfate Esters, Phosphate Esters, Thiophosphate Esters, and Borate Esters

Esters react with acids to liberate heat along with alcohols and acids. Strong oxidizing acids may cause a vigorous reaction that is sufficiently exothermic to ignite the reaction products. Heat is also generated by the interaction of esters with caustic solutions. Flammable hydrogen is generated by mixing esters with alkali metals and hydrides.

III

6.1(b)

3348

Hydrolysis DT50 <1 hr. Stable to light, DT50 >100 days. Stable at 54 deg C.

P261, P264, P270, P272, P273, P280, P301+P312, P302+P352, P321, P330, P333+P313, P363, P391, P501

H302

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.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Some may burn but none ignite readily. Containers may explode when heated. Some may be transported hot. For UN3508, be aware of possible short circuiting as this product is transported in a charged state. (ERG, 2016)

|Warning|H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]|P261, P264, P270, P272, P273, P280, P301+P312, P302+P352, P321, P330, P333+P313, P363, P391, and P501|Aggregated GHS information provided by 185 companies from 5 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: SMALL FIRE: Dry chemical, CO2, water spray or regular foam. LARGE FIRE: Water spray, fog or regular foam. Do not scatter spilled material with high-pressure water streams. Move containers from fire area if you can do it without risk. Dike fire-control water for later disposal. FIRE INVOLVING TANKS: Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent dust cloud. Avoid inhalation of asbestos dust. SMALL DRY SPILL: With clean shovel, place material into clean, dry container and cover loosely; move containers from spill area. SMALL SPILL: Pick up with sand or other non-combustible absorbent material and place into containers for later disposal. LARGE SPILL: Dike far ahead of liquid spill for later disposal. Cover powder spill with plastic sheet or tarp to minimize spreading. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. (ERG, 2016)

LD50 Rat (male) oral 982 mg/kg|LD50 Rat (female) oral 864 mg/kg|LD50 Mouse oral 673 mg/kg|LD50 Rat oral 896 mg/kg|For more Non-Human Toxicity Values (Complete) data for 2,4-D 2-ETHYLHEXYL ESTER (6 total), please visit the HSDB record page.

/AQUATIC SPECIES/ In studies conducted according to the guidelines of the US Environmental Protection Agency, 2,4-D acid and ethylhexyl ester had no effect on the early life stages, embryo hatch, larval weight, or larval length of the fathead minnow (Pimephales promelas) at concentrations of 12.6-102 mg/L for up to 32 days (acid). The 32-day NOEC for the acid was 63.4 mg/L, comparable to the 33-day NOEC for the diethanolamine salt of 29.1 mg/L. The ethylhexyl ester was more toxic, with a 32-day NOEC of 0.12 mg/L... .|/AQUATIC SPECIES/ The esters of 2,4-D are clearly more toxic to invertebrate species such as the tidewater silverside (Menidia beryllina), Atlantic silverside (Menidia menidia), grass shrimp (Palaemonetes puqio), pink shrimp (Panaeus duorarum), and Dungeness crab (Cancer magister) than is the dimethylamine salt or the acid. The same is true for formulated 2-ethylhexyl ester.

2,4-D, 2-ethylhexyl ester 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(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 33,000(SRC), determined from a log Kow of 5.78(2) and a regression-derived equation(3), indicates that 2,4-D, 2-ethylhexyl ester is expected to be immobile in soil(SRC). Volatilization of 2,4-D, 2-ethylhexyl ester from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 1.8X10-5 atm-cu m/mole(2). However, adsorption to soil is expected to attenuate volatilization(SRC). 2,4-D, 2-ethylhexyl ester is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 3.59X10-4 mm Hg(2). Field studies have resulted in half-lives of 1 to 51 days when applied as a spray and 4-16 days when applied in granulate form(3).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 33,000(SRC), determined from a log Kow of 5.78(2) and a regression-derived equation(3), indicates that 2,4-D, 2-ethylhexyl ester is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 1.8X10-5 atm-cu m/mole(2). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 94 hours and 820 hours, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column(SRC). The estimated volatilization half-life from a model pond is 51 months if adsorption is considered(4). According to a classification scheme(5), an estimated BCF of 5,600(SRC), from its log Kow(2) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is very high(SRC). Hydrolysis of 2,4-D, 2-ethylhexyl ester is expected to yield the parent compound 2,4-D acid(SRC). A base-catalyzed second-order hydrolysis rate constant of 2.3 L/mole-sec(SRC) was estimated using a structure estimation method(7); this corresponds to half-lives of 35 and 3.5 days at pH values of 7 and 8, respectively(7). Biodegradation data were not available(SRC, 2005).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2,4-D, 2-ethylhexyl ester, which has a vapor pressure of 3.59X10-4 mm Hg at 25 °C(2) is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 2,4-D, 2-ethylhexyl ester 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 27 hrs(SRC), calculated from its rate constant of 15X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). 2,4-D, 2-ethylhexyl has been reported to be stable to light(2).

The rate constant for the vapor-phase reaction of 2,4-D, 2-ethylhexyl ester with photochemically-produced hydroxyl radicals has been estimated 15X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 27 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Hydrolysis of 2,4-D, 2-ethylhexyl ester is expected to yield the parent compound 2,4-D acid(SRC). A base-catalyzed second-order hydrolysis rate constant of 2.3 L/mole-sec(SRC) was estimated using a structure estimation method(2); this corresponds to half-lives of 35 and 3.5 days at pH values of 7 and 8, respectively(2). 2,4-D, 2-ethylhexyl has been reported to be stable to light(3).

An estimated BCF of 5,600 was calculated for 2,4-D, 2-ethylhexyl ester(SRC), using a log Kow of 5.78(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is very high(SRC), provided the compound is not altered physically or chemically once released into the environment(SRP).

The Koc of 2,4-D, 2-ethylhexyl ester is estimated as 33,000(SRC), using a log Kow of 5.78(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that 2,4-D, 2-ethylhexyl ester is expected to be immobile in soil.

The Henry's Law constant for 2,4-D, 2-ethylhexyl ester is 1.8X10-5atm-cu m/mole(1). This Henry's Law constant indicates that 2,4-D, 2-ethylhexyl ester is expected to volatilize from water surfaces(2). 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)(2) is estimated as 94.4 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 34.2 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 51 months when adsorption is considered(3). Volatilization of 2,4-D, 2-ethylhexyl ester from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 1.8X10-5 atm-cu m/mole(1). However, adsorption to soil is expected to attenuate volatilization(SRC). 2,4-D, 2-ethylhexyl ester is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure of 3.59X10-4 mm Hg(1).

Occupational exposure to 2,4-D, 2-ethylhexyl ester may occur through inhalation and dermal contact with this compound at workplaces where 2,4-D, 2-ethylhexyl ester is produced or used. (SRC)

A maximum 2,4-D concentration in serum of 1075 ppm was detected 5 hr after /English pointer dogs were given a/ po dose of 220 mg/kg. A maximum 2,4-D, concentration in urine of 1792 ppm was detected 2 hr after a po dose of 175 mg/kg, while 25 hr after that dose kidney tissue contained 271 ppm. /2,4-D/

The pharmacokinetics of the 2-ethylhexyl ester of 2,4-D were investigated following a single oral administration of 130 mg/kg body weight dose to both male and female Fischer 344 rats. Blood samples were drawn from 24 rats per sex in serial groups of 3 at intervals of 0.25, 0.5, 1, 2, 4, 8, 24, and 72 hours post dosing and urine was collected from the 72 hours group at 12 hour intervals. The most significant finding from this evaluation was the absence of any 2-ethylhexyl ester of 2,4-D in either the blood or urine for either sex evaluated (limit of quantification 10 ppb). Conversely 2,4-D acid was detected in both blood and urine. The present data indicate that the 2-ethylhexyl ester of 2,4-D is converted very rapidly to 2,4-D acid, and that the acid is then excreted into the urine. A similarity exists in interval excretion data with that seen in previous investigations with 2,4-D acid. Indications are that the 2,4-D acid is probably derived via the hydrolysis of the 2-ethylhexyl ester moiety and is eliminated from the body in the same manner as the orally administered 2,4-D acid. It is therefore anticipated from these results that the 2-ethylhexyl ester of 2,4-D should be toxicologically comparable to 2,4-D acid itself.|2,4-D 2-ethylhexyl ester is hydrolysed to 2,4-D by esterase enzymes present in the gut wall, in blood plasma, in liver cells and in skin. Any 2,4-D /ethylhexyl ester/ absorbed orally or dermally is hydrolysed to 2,4-D, the acid ionic form.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Inhalation of material may be harmful. Contact may cause burns to skin and eyes. Inhalation of Asbestos dust may have a damaging effect on the lungs. Fire may produce irritating, corrosive and/or toxic gases. Some liquids produce vapors that may cause dizziness or suffocation. Runoff from fire control may cause pollution. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. (ERG, 2016)

Skin decontamination: Flush contaminating chemicals from eyes with copious amounts of water for 10 to 15 minutes. If irritation persists, an ophthalmological examination should be performed. /Chlorophenoxy Herbicides/|Ingestions of these herbicides are likely to be followed by vomiting and diarrhea due to the irritant properties. ... Activated charcoal is probably effective in limiting irritant effects and reducing absorption of most or all of these herbicides. Aluminum hydroxide antacids may be useful in neutralizing the irritant actions of mose acidic agents. Sorbitol should be given to induce catharsis if bowel sounds are present and if spontaneous diarrhea has not already commenced. Dehydration and electrolyte disturbances may be severe enough to require intravenous fluids. There are no specific antidotes for poisoning by these herbicides. /Other Herbicides/|Administer intravenous fluids to accelerate excretion of the chlorophenoxy compound, and to limit concentration of the toxicant in the kidney. A urine flow of 4-6 mL/minute is desirable. Intravenous saline/dextrose has sufficed to rescue comatose patients who drank 2,4-D and mecoprop several hours before hospital admission. CAUTION: Monitor urine protein, cells. BUN, serum creatine,serum electrolytes, and fluid intake/output carefully to insure that renal function remains unimpaired and that fluid overload does not occur. /Chlorophenoxy Herbicides/|Forced alkaline diuresis has been used successfully in management of suicidal ingestions of chlorophenoxy compounds, especially when initiated early. Alkalinizing the urine by including sodium bicarbonate ... in the intravenous solution accelerates excretion of 2,4-D dramatically and mecoprop excretion substantially. Urine pH should be maintained between 7.6 and 8.8. Include potassium chloride to offset increased potassium losses. ... It is crucial to monitor serum electrolytes carefully, especially potassium and calcium. There may possibly be some hazard to the kidneys when urine concentrations of toxicant are very high, so the integrity of renal function and fluid balance should be monitor carefully as the chlorophenoxy compound is excreted. Renal failure has occured in patients with severe intoxication during alkaline diuresis. /Chlorophenoxy Herbicides/|Hemodialysis is not likely to be of significant benefit in poisonings by chlorophenoxy compounds. It has been used in four patients who survived intoxication. However, given the highly protein-bound nature of these herbicides and lack of any other evidence , hemodialysis is not recommended. /Chlorophenoxy Herbicides/

2,4-D, 2-ethylhexyl ester

Selected products: 'Esteron 6E'; 'Esteron 99C'; 'Lentemul'; ...'Barrage'; 'Brush-Rhap'; 'Fivestar'; 'Low Vol 4 Ester'; 'Salvo'; 'Weed Rhap LV-4D'; 'Weedone LV4'; 'Weed-Rhap'. Mixtures: 'Adrenalin' (+ imazamox); 'B-4' (+bromoxynil heptanoate+ bromoxynil octanoate); 'Broadsword' (+dicamba+ triclopyr-butotyl) (dicamba as butotyl ester); 'Oasis' (+imazapic); 'Shotgun' (+atrazine); 'Tiller' (+fenoxaprop-P-ethyl+ MCPA-2-ethylhexyl); 'Weedone 638 Solventless' (+2,4-D).

Method: 8321A: Procedure: high performace liquid chromatography coupled with either thermospray-mass spectrometry and/or ultraviolet detection; Analyte: 2,4-D, ethylhexyl ester; Matrix: wastewater, ground water, and soil/sediment matrices; Detection Limit: 1.2 ng.[