2,4-D 3-butoxypropyl ester

335.22

335.22

U3L3P46PKT

DTXSID0038910

44.76000

4.12220

1.2109

451.39°C (rough estimate)

152.8ºC

1.5300 (estimate)

ESTER FORMULATIONS HAVE LOW SOLUBILITY IN WATER. /2,4-D; SRP: THEY CAN BE DISPERSED AS AQUEOUS EMULSIONS/|Soluble in oils /2,4-D esters/

Storage temp: Ambient /2,4-D esters/

2.83E-07mmHg at 25°C

Volatility: 4 ug/sq cm/hr at 28.8 l/hr flow rate at 30 °C. /Technical grade/|Decomposes to salt in alkaline water, half-life at pH 9 is 4.4 hr, at pH 6, half-life is 180 days. /From table/|/2,4-D esters/ are generally immiscible or insoluble in water, but gradual hydrolysis /SRP: will occur in very alkaline waters/. /2,4-D esters/|Fuel oil-like odor /2,4-D esters/ SRP: Technical product.|SRP: 2,4-D ESTERS ARE SOLUBLE IN NON-POLAR ORGANIC SOLVENTS SUCH AS HEXANE, BENZENE, ACETONE, AND ALCOHOLS /2,4-D ESTERS/

May attack some forms of plastics /2,4-D esters/

III

6.1(b)

3348

Shelf life of ester formulations varies, depending on the emulsifying system. Some retain satisfactory emulsifying properties after 3 yr. /2,4-D/

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U240, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste. /2,4-D acid, salts & esters/|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: Non-combustible 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/|Landfill: Recommendable method: Incineration. Not recommendable method: Discharge to sewer. Peer-review: Incinerate at high temp or PCDDs may be formed. /2,4-D/|The following wastewater treatment technologies have been investigated for 2,4-D and related herbicides: Concentration process: Resin adsorption. /2,4-D and related herbicides/

WHO; Environ Health Criteria: 2,4-Dichlorophenoxyacetic Acid (2,4-D) (1984)|Nat'l Research Council Canada; Phenoxyherbicides (1978) NRCC No. 16075|Vet Admin Rev Lit on Herbicides (1981) VA Contract No. V101(93)p-823|Norris LA; The Movement, Persistance, and Fate of the Phenoxy Herbicides and TCDD in the Forest; Residue Rev 77: 65-135 (1981)|Que Hee SS, Sutherland RG; The Phenoxyalkanoic Herbicides. Volume 1: Chemistry, Analysis, and Environmental Pollution. CRC Press, Boca Raton, Florida, 1981.

EXTINGUISH WITH DRY CHEMICALS, FOAM, OR CARBON DIOXIDE. WATER MAY BE INEFFECTIVE. COOL EXPOSED CONTAINERS WITH WATER. /2,4-D ESTERS/

Smoking, eating, and drinking before washing should be absolutely prohibited when any pesticide ... is being handled or used. /Pesticides/|/When/ cleaning glassware and spray equipment: wash thoroughly with water and detergent soln. Alcohol or ketone type solvents may be used with ester formulations. Preferably, equipment should not be used for application of other pesticides or fertilizers. /2,4-D ester/|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.

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.

Acute eye or skin irritation ... has been reported in agricultural and forestry workers following occupational exposure. /2,4-D herbicides/|Irritating to skin and eyes. /2,4-D esters/

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 10 mg/cu m. /2,4-D/

Recommended Exposure Limit: 10 Hr Time-Weighted Avg: 10 mg/cu m. /2,4-D/

D016; A waste containing 2,4-D (such as 2,4-D butoxypropyl ester) may or may not be characterized as a hazardous waste following testing by the Toxicity Characteristic Leaching Procedure as prescribed by the Resource Conservation and Recovery Act (RCRA) regulations.|U240; A toxic waste when a discarded commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate. /2,4-D, salts and esters/

Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 100 lb or 45.4 kg. The toll free number of the NRC is (800) 424-8802; In the Washington D.C. metropolitan area (202) 426-2675. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b). /2,4-D, salts and esters/

D016; A solid waste containing 2,4-D (such as 2,4-D butoxypropyl ester) may or may not become characterized as a hazardous waste when subjected to the Toxicity Characteristic Leaching Procedure listed in 40 CFR 261.24, and if so characterized, must be managed as a hazardous waste.|U240; As stipulated in 40 CFR 261.33, when 2,4-D acid, salts & esters as commercial chemical products or manufacturing chemical intermediates or off-specification commercial chemical products or manufacturing chemical intermediates, become wastes, they must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5). /2,4-D, salts and esters/

LD50 Rat oral 500 mg/kg

TERRESTRIAL FATE: 2,4-D, its salts and esters are systemic herbicides, widely used for weed control in cereals and other crops at 0.28 to 2.3 kg/ha, the highest rate persisting in soil about 30 days. /2,4-D/|Various amounts of 2,4-D products applied to a target area may be distributed in the general environment, within a few hours or days, by the movements of air, water, or soil, particularly during periods of rain, high winds, or high temperature. Persistence or accumulation of 2,4-D residues from normal use is occasionally possible, mainly under dry or cold conditions where there is little biological activity. /2,4-D products/|AQUATIC FATE: Persistence in aquatic systems depends on the water type, organic particulate matter, rain, sunlight, temperature, microbial degradation, volatilization, and oxygen content of the water. Accumulation in bottom sediments may also be a factor, but in general, not for the phenoxys. Microbial activity is the major means for detoxification of the phenoxys in soils, but is relatively unimportant in natural waters, but dominates in bottom mud sediments and in sludge.|From limited data available, it may be concluded that any phenoxy herbicide, whether applied as ester ... formulations, may be chemically transformed to the same phenoxyalkanoic anion in soil and water at rates dependent on pH. These anions would presumably reassociate with a variety of inorganic cations present in the soil to maintain electrical neutrality, and then undergo leaching and biological degradation. /Phenoxy esters/

AQUATIC FATE: ... 2,4-D esters hydrolyze quickly (k= 4.3 l/mol/sec) ... to form anions (pH > 4) and free acid (pH < 4). /SRP: Basic hydrolysis at pH 9 is 3 orders of magnitude faster than hydrolysis at pH 6./ /2,4-D esters/|/2,4-D esters, irradiated with wavelengths longer than 290 nm/ in organic solvents or at high concentrations in water, ... yielded ... 2-, and 4-chlorophenoxyacetic acid esters. Ester photolysis rates were also found to be pH independent. /2,4-D esters/|Photodecomposition of 2,4-D ... leads to the formation of a variety of products but commonly involves reductive dechlorination of the acid, esters, and salts in aqueous or in organic solutions, with 2,4-dichlorophenol acting as a catalyst for the breakdown of 2,4-D, which may involve rupture of the aromatic ring. ... Carbon dioxide is the final oxidation product when aqueous solutions of 2,4-D undergo photodecomposition. /2,4-D/|BASIC & ACID HYDROLYSIS OF 2,4-D ESTERS YIELDED 2,4-D & CORRESPONDING ALCOHOL. MAJOR PHOTOREACTION OF 2,4-D ESTERS @ WAVE-LENGTH LESS THAN 290 NM INVOLVED CLEAVAGE OF ORTHO C-CL BOND. /2,4-D/|Photodegradation occurs at ortho chlorine with reductive dechlorination at 300 nm. /2,4-D/

2,4-D and its derivatives can be absorbed via the oral, dermal, and inhalation routes. General population exposure is mainly by the oral route, but under occupational and bystander exposure conditions, the dermal route is by far the most important. /2,4-D and its derivatives/|Sprayers are at increased exposure. Aerial spraying will cause more of the general population to be potentially exposed.

Leaves absorb nonpolar (ester) forms most readily. ... The esters of 2,4-D tend to resist washing from plants and are rapidly converted to the acid by the plants. ... Following foliar absorption, 2,4-D translocates within the phloem, probably moving with food material. Following root absorption, it may move upward in the transpiration stream. Translocation is influenced by the growth status of the plant. Accumulation of the herbicide occurs principally at the meristematic regions of shoots and roots. /2,4-D and its esters/

Plants hydrolyze 2,4-D esters to 2,4-D, which is the active herbicide. ... Further metabolism ... occurs through three mechanisms, namely, side chain degradation, hydroxylation of the aromatic ring, and conjugation with plant constituents.|HERBICIDAL ACTIVITY OF ESTERS, NITRILES, AMINES (&, OF COURSE, SALTS) APPEARS SIMILAR IF NOT IDENTICAL TO PARENT ACID. THIS IS APPARENTLY DUE TO PRESENCE OF HYDROLYTIC ENZYMES IN PLANTS & IN SOIL MICROORGANISMS THAT CONVERT THESE DERIVATIVES TO PARENT ACID. /2,4-D ESTER/|2,4-D ESTERS ARE HYDROLYZED IN ANIMALS. THE PHENOXY ACIDS ARE EXCRETED PREDOMINANTLY AS SUCH IN THE URINE OF RATS AFTER THEIR ORAL ADMIN, ALTHOUGH MINOR PORTION IS CONJUGATED WITH AMINO ACIDS GLYCINE & TAURINE & WITH GLUCURONIC ACID. /2,4-D AND ESTERS/|Chlorophenoxy acid derivatives are metabolized via participation of the hepatic microsomal mixed-function oxidase system. Thus, administration of 2,4-D amine salt and its butyl ester ... to rats induced the enzyme system (aminopyrine demethylase ... and aniline hydroxylase) ... although the degree of induction was substantially lower than that from phenobarbital. Prolonged administration of 2,4-D amine salt (0.1 LD50) showed cumulative effects reflected by both clinical and biochemical changes. Stimulation of mixed-function oxidase system may be one of the methods for reducing toxicological effects of this type of compounds.|For more Metabolism/Metabolites (Complete) data for 2,4-D, BUTOXYPROPYL ESTER (10 total), please visit the HSDB record page.

THESE HERBICIDES DO NOT ACCUM IN ANIMALS. THEY ARE NOT EXTENSIVELY METAB BUT ARE ACTIVELY EXCRETED INTO THE URINE ... THEIR PLASMA HALF-LIFE IN MAN IS ABOUT 1 DAY. /CHLOROPHENOXY COMPOUNDS/

... /CHLOROPHENOXY CMPD INCL 2,4-D ESTERS/ EXERT THEIR HERBICIDAL ACTION BY ACTING AS GROWTH HORMONES IN PLANTS. /CHLOROPHENOXY COMPOUNDS/

SIXTEEN SAMPLES OF 2,4-D, AS ESTERS AND AMINE SALTS, WERE ANALYZED FOR CHLORINATED DIBENZO-P-DIOXINS. DI-, TRI-, & TETRA-CHLORODIBENZO-P-DIOXINS WERE IDENTIFIED. ESTER FORMULATIONS SHOWED MUCH HIGHER LEVELS OF CONTAMINATION THAN AMINE /2,4-D ESTERS AND AMINE SALTS/|... Trace levels of chlorinated dibenzodioxins have been found in ... ester formulations. ... /SRP: These are the 2,7-Di-, 1,3,7-Tri, 1,3,4,8-Tetra-, and 1,3,6,8-Tetra- dioxins which are comparatively less toxic./ /2,4-D esters/

Basic treatment: Establish a patent airway. Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with normal saline during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . Monitor body temperature and treat if necessary. /Chlorophenoxy herbicides and related compounds/|Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious. Positive pressure ventilation techniques with a bag valve mask device may be beneficial. Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start an IV with lactated Ringer's /SRP: "To keep open", minimal flow rate/. Titrate to maintain adequate urine flow. Watch for signs of fluid overload. Monitor cardiac rhythm and treat arrhythmias if necessary ... . Consider drug therapy for pulmonary edema ... . For hypotension with signs of hypovolemia, administer fluid cautiously. Consider vasopressors if hypotensive without signs of hypovolemia ... . Treat seizures with diazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Chlorophenoxy herbicides and related compounds/|Alkaline diuresis should be used to treat acute poisoning with chlorophenoxy herbicides or ioxynil in the presence of coma or other poor prognostic indicators, such as acidemia, or if plasma total chlorophenoxy concentrations are 0.5 g/l or more.

IN THREE HUMAN BEINGS, ABSORPTION OF AN UNSPECIFIED ESTER OF DICHLOROPHENOXYACETIC ACID THROUGH SKIN CAUSED POLYNEURITIS, BUT WITH NO DISTURBANCE OF EYES OR VISION. /2,4-D ESTER/|SUBJECTIVE CLINICAL SYMPTOMS REPORTED AMONG WORKERS USING VARIOUS ESTERS & SALTS OF 2,4-D INCL RAPID FATIGUE, HEADACHE, LOSS OF APPETITE & PAIN IN THE REGION OF THE LIVER & STOMACH. SENSITIVITY TO TASTE & SMELL WAS LOWERED. /2,4-D ESTERS AND SALTS/|The chlorophenoxy herbicides have produced contact dermatitis in man ... . /Chlorophenoxy compounds/|IN THE BODY, THE ... ESTERS OF CHLOROPHENOXY COMPOUNDS ARE HYDROLYZED FAIRLY RAPIDLY SO THAT THE MAMMALIAN TOXICITY OF EACH COMPOUND DEPENDS MAINLY ON THE ACID INVOLVED. /CHLOROPHENOXY HERBICIDES/|RESULTS OF SINGLE COHORT STUDY OF SMALL NUMBER OF WORKERS EXPOSED TO VARIOUS HERBICIDES, INCL 2,4-D ... ARE NOT SUFFICIENT TO EVALUATE CARCINOGENICITY OF 2,4-D TO MAN ... /SRP: SPECIFIC SALT OR ESTER NOT SPECIFIED. EPIDEMIOLOGICAL STUDIES ARE GENERALLY CONFOUNDED BECAUSE OF THE COEXPOSURE TO OTHER CHEMICALS EG 2,4,5-T WHICH ALSO HAS 2,3,7,8-TCDD CONTAMINANT./

Esters of /2,4-D/ are formulated as /emulsifiable concentrates/ (ec). /2,4-D/|GRADES OR PURITY: TECHNICAL, 99%; 64% IN PETROLEUM OIL /2,4-D ESTERS/

Chlorophenoxy herbicides are applied alone or as mixtures with other herbicides, in solutions, dispersions, or emulsions in water &/or oil, using equipment that produces large droplets to avoid spray drift. /Chlorophenoxy herbicides/

Whole Plants: Macerate plant tissue with water. Add 0.6 M sodium hydroxide. Reflux or heat on a steam bath. Filter and wash the filter cake with water. Combine the filtrates. Suspend the filter cake in 2 M hydrochloric acid. Reflux or heat on a steam bath. Extract with equal volumes of ether (x3). Combine these with the filtrate. The above acid hydrolysis is done in case there are conjugates resistant to alkaline hydrolysis. The recovery of the above using only the alkaline hydrolysis was greater than 89 to 92% with (14)C-labeled material. ... Continue with a liquid/liquid cleanup, followed by electron capture/gas chromatography quantitiation ... using a pyrex column ... packed with 1:1 10% DC 200/15% QF-1 on 80/100 mesh Chromosorb W (AW-DMCS). The injector, column, and (63)Ni electron capture detector temperatures are 220, 195, and 220 °C, respectively. The flow rate of nitrogen carrier is 80 ml/min. /2,4-D and esters or salts of 2,4-D/|Water: Filter out any particulate matter. Take a 1-l or smaller volume sample. Saturate with sodium chloride. Adjust the pH to < 2 with hydrochloric acid. Extract with acetonitrile (5 x 500 ml). Adjust the saline solution to > pH 13 and extract with diethyl ether (3 x 500 ml). Reacidify to < pH 2 with hydrochloric acid and extract with acetonitrile (5 x 500 ml). Extraction is approximately 99% efficient. ... Continue with a liquid/liquid cleanup, followed by electron capture/gas chromatography quantitation ... using a pyrex column ... packed with 1:1 10% DC 200/15% QF-1 on 80/100 mesh Chromosorb W (AW-DMCS). The injector, column, and (63)Ni electron capture detector temperatures are 220, 195, and 220 °C; respectively. The flow rate of nitrogen carrier is 80 ml/min. /2,4-D and esters or salts of 2,4-D/|A GLC/MASS SPECTROMETRIC METHOD IS PRESENTED FOR ANALYSIS OF 2,4-D IN COMPOUND FORMULATIONS, TOGETHER WITH CONCURRENT DETECTION AND QUANTITATION OF RELATED COMPOUNDS. /2,4-D COMPOUNDS/|ELECTRON-IMPACT MASS SPECTRA FOR CHLOROPHENOXY HERBICIDES WERE OBTAINED & USED TO ESTABLISH SELECTIVE ION-MONITORING TECHNIQUES FOR AIRBORNE 2,4-D CMPD. TOTAL-EFFLUENT GC/MS IS EXTREMELY ADVANTAGEOUS FOR MAX SENSITIVITY & REPRODUCIBILITY IN ENVIRONMENTAL ANALYSIS. /2,4-D COMPOUNDS/

Fat Samples: Dissolve sample in hot ethanol; reflux for 1 hr, and chill. Add 0.1 N sodium hydroxide. Extract with diethyl ether. ... Continue with a liquid/liquid cleanup, followed by electron capture/gas chromatography quantitation ... using a pyrex column ... packed with 1:1 10% DC 200/15% QF-1 on 80/100 mesh Chromosorb W (AW-DMCS). The injector, column, and (63)nickel electron capture detector temperatures are 220, 195, and 220 °C, respectively. The flow rate of nitrogen carrier is 80 ml/min.|Plasma: This is based on the method for the drug Clofibrate. Add enough hydrochloric acid to the sample for pH < 2. Extract with equal volumes of ether (x3). To measure the 2,4-D in complex form, add aqueous sodium hydroxide to the aqueous layer and ... continue with a liquid/liquid cleanup, followed by electron capture/gas chromatography quantitation ... using a pyrex column ... packed with 1:1 10% DC 200/15% QF-1 on 80/100 mesh Chromosorb W (AW-DMCS). The injector, column, and (63)nickel electron capture detector temperatures are 220, 195, and 220 °C; respectively. The flow rate of nitrogen carrier is 80 ml/min.|Metabolites: This is a general method recommended by McLeod and Wales. Reflux 5 g of tissue for 1 hr with 19 ml of benzene and separate the supernatant from particulates by filtration through a medium-porosity fritted glass funnel via negative pressure. Re-extract the particulate matter again with fresh 10 ml (19:1) acetone/benzene. Combine the filtrates and concentrate to 25 ml. Use the low-temperature bath apparatus as laid out by McLeod and Wales. Further characterization of the actual metabolites has not been accomplished. There is much room for further separation technology.|In General: Renberg's method is simple, but not very quantitative (70 to 82% at 1 to 3 ppm). Homogenize 5 g of tissue in (5 ml of hexane + 10 ml of acetone), eg, with an insertable homogenizer in a dropping funnel with a glass filter disc. Drop the liquid into 1 M hydrochloric acid (5 ml) (use N2 pressure if necessary) in a separatory funnel. Homogenize again with 10 ml of hexane + 5 ml of diethyl ether. Transfer the upper phase to the separatory funnel, shake, and transfer the upper phase to a centrifuge tube. Reextract the aqueous phase with 2 ml/2 ml of diethyl ether/hexane (x2). Combine the extracts in the centrifuge tube. Add sodium sulfate (100 to 300 mg) and centrifuge. Transfer the supernatant to a weighed flask, rinse the sodium sulfate with diethyl ether (3 x 2 ml), combine the washings and supernatant, evaporate the solvent, and calculate the fat content. Dissolve the residue in benzene (1 ml/25 mg fat). Take 3 ml of this and add 3 ml of 0.1 M sodium hydroxide solution. Shake for 5 min and remove the benzene phase. Continue with one of the following methods: 1) a liquid/liquid cleanup, followed by electron capture/gas chromatography quantitation ... using a pyrex column ... packed with 1:1 10% DC 200/15% QF-1 on 80/100 mesh Chromosorb W (AW-DMCS). The injector, column, and (63)nickel electron capture detector temperatures are 220, 195, and 220 °C; respectively. The flow rate of nitrogen carrier is 80 ml/min. 2) an ion exchange clean up in 0.1 M sodium hydroxide.|Muscle, Liver, and Kidney: This is based on the method of Clark et al, who achieved 88 to 93% recoveries for 2,4-D, 2,4,5-T, and Silvex. Freeze-dry the thawed samples, then homogenize with hot ethanol, and reflux for 1 hr. Filter out the solids and chill the ethanol filtrate in an ice bath. Filter the precipitated fat from the chilled solution. Wash with chilled ethanol. Evaporate the alcohol filtrate. Digest the rest of the solid residue for 2 hr with papain at pH 5.0 and 55 °C. Extract with equal volumes of ether (x3). ... Continue with a liquid/liquid cleanup, followed by electron capture/gas chromatography quantitation ... using a pyrex column ... packed with 1:1 10% DC 200/15% QF-1 on 80/100 mesh Chromosorb W (AW-DMCS). The injector, column, and (63)nickel electron capture detector temperatures are 220, 195, and 220 °C; respectively. The flow rate of nitrogen carrier is 80 ml/min. An ion exchange cleanup can be utilized if 3 ml of 0.1 M sodium hydroxide is added with evaporation of the ether layer to 3 ml.

HERBICIDES