(4-Chlorophenoxy)acetic acid

186.59

186.59

1211804

204-581-3

4EMM3U5P3K

8769

DTXSID9034282

Prisms or needles from water

29189090

46.5

2.25

White to light beige crystalline

1.525 g/cm³

156-157 °C

315.2±17.0 °C at 760 mmHg

144.4±20.9 °C

1.558

In water, 957 mg/L at 25 deg C

0-6°C

3.2X10-4 mm Hg at 25 deg C (est)

Oral-Rat LD50: 850 mg/kg; Abdominal cavity-mouse LD50: 680 mg/kg

Flammable; burning produces toxic chloride gas

Henry's Law constant = 6.4X10-8 atm cu m/mol at 25 °C (est)

pKa = 3.56

Hydroxyl radical rate constant = 1.1X10-11 cu cm/molec-sec at 25 °C (est)

IRRITANT

2811

1

22-R22

22-24/25

AG0175000

Xn,Xi

The warehouse is ventilated, low temperature and dry; stored and transported separately from food materials

It is stable at elevated temperatures (54 deg C) and on exposure to metals, but degrades (30% loss in 24 hours) on exposure to sunlight.

P264, P270, P301+P312, P330, 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.

USEPA/Office of Pesticide Programs; Reregistration Eligibility Decision Document - 4-Chlorophenoxy-acetic Acid (4-CPA), EPA 738-R-97-001 (March 1997). The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the U.S.[Available from, as of June 21, 2006: http://www.epa.gov/pesticides/reregistration/status.htm]|BOVEY RW; PHYSIOLOGICAL EFFECTS OF PHENOXY HERBICIDES IN HIGHER PLANTS. IN: THE SCIENCE OF 2,4,5-T AND ASSOCIATED HERBICIDES, (JOHN WILEY & SONS: NY) CHAPTER 7: 217-38 (1980). RESEARCH ON THE PHYSIOLOGY AND MODE-OF-ACTION OF PHENOXY HERBICIDES INCLUDING 4-CPA ARE REVIEWED.

|Warning|H302: Harmful if swallowed [Warning Acute toxicity, oral]|P264, P270, P301+P312, P330, and P501|H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]|Aggregated GHS information provided by 71 companies from 3 notifications to the ECHA C&L Inventory.|P264, P270, P280, P301+P312, P305+P351+P338, P330, P337+P313, and P501

If material is released or spilled, flush with water, wear all purpose canister mask, rubber vinyl-coated gloves, face shield for eye protection.

If material is released or spilled, flush with water ... .

Individuals with chronic skin disease or known hypersensitivity to /chlorophenoxy herbicides/ should either avoid using them or take strict precautions to avoid contact (respirator, gloves, etc.). /Chlorophenoxy compounds/

moderately

LD50 Rat oral 850 mg/kg|LD50 Mouse ip 680 mg/kg|LD50 Rabbit dermal >2,000 mg/kg /from table/

4-Chlorophenoxyacetic acid's production may result in its release to the environment through various waste streams; it's use as a plant growth regulator and as an aid in setting fruit(1) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 18(SRC), determined from a structure estimation method(2), indicates that 4-chlorophenoxyacetic acid is expected to have very high mobility in soil(SRC). Furthermore, the pKa of 4-chlorophenoxyacetic acid is 3.56(3), indicating it will exist primarily as an anion under environmental conditions and anions generally possess greater mobility in soils than neutral compounds(4). Volatilization from moist soil surfaces will not be an important environmental fate process since anions do not volatilize(SRC). 4-Chlorophenoxyacetic acid is not expected to volatilize from dry soil surfaces(SRC), based upon an estimated vapor pressure of 3.2X10-4 mm Hg at 25 °C(SRC), determined from a fragment constant method(5). The half-life of 4-chlorophenoxyacetic acid in a clay loam soil under field conditions was 20 days(6).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 18(SRC), determined from a structure estimation method(2), indicates that 4-chlorophenoxyacetic acid is not expected to adsorb to suspended solids and sediment(SRC). The pKa of 4-chlorophenoxyacetic acid is 3.56(3), indicating it will exist primarily as an anion under environmental conditions. Volatilization from water surfaces is not an important environmental fate process since anions do not volatilize(SRC). According to a classification scheme(4), an estimated BCF of 3(SRC), from a log Kow of 2.25(5) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation studies using soil(7), and sewage inocula(8), suggest that biodegradation in water may occur. 4-Chlorophenoxyacetic acid exposed to natural sunlight for 24 hours was degraded 30%, suggesting that photolysis in sunlit surface waters may be important(9).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 4-chlorophenoxyacetic acid, which has an estimated vapor pressure of 3.2X10-4 mm Hg at 25 °C(2), is expected to exist solely in the vapor-phase in the ambient atmosphere. Vapor-phase 4-chlorophenoxyacetic acid 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 35 hours(SRC), calculated from its rate constant of 1.1X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). 4-Chlorophenoxyacetic acid was degraded 30% upon exposure to natural sunlight over the course of 24 hours, suggesting photodegradation is an important environmental fate process(4).

The rate constant for the vapor phase reaction of 4-chlorophenoxyacetic acid with photochemically produced hydroxyl radicals has been estimated to be 1.1X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 35 hours at an atmospheric concn of 5X10+5 hydroxyl radicals per cu cm(1). 4-Chlorophenoxyacetic acid was stable to hydrolysis (half-life > 30 days) at pH 5, 7, and 9(2). 4-Chlorophenoxyacetic acid was degraded 30% upon exposure to natural sunlight over the course of 24 hours(2).|The sunlight photolysis of 4-chlorophenoxyacetic acid in natural waters was found to produce catechol and phenol by either the reaction with solvated electrons or hydroxyl radicals formed via the sensitization of naturally occurring substances(1). Which ever process is operating, the isolation of the formate ester of phenol as a photolysis intermediate indicates a free radical rather then ionic (hydrolytic) pathway(2). Laboratory irradiation of 4-chlorophenoxyacetic acid in ethanol using a mercury vapor lamp produced phenol, 2-coumaranone, and phenoxyacetic acid(3).|Under sunlight or UV (300-450 nm) 4-CPA in aqueous solutions decomposed mainly to p-chlorophenol, phenol, hydroquinone, p-chlorophenyl formate, phenoxyacetic acid, p-hydroxyphenoxacetic acid and humic acids. In the presence of cyanide ions, irradiation of 4-CPA produced p-chlorobenzonitrile.

An estimated BCF of 3 was calculated for 4-chlorophenoxyacetic acid(SRC), using a log Kow of 2.25(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 Rf value for 4-chlorophenoxyacetic acid ranged from 0.74 at pH 4.0 to 0.93 at pH 7 using a Rothansted silty clay loam(1). At pH 7.8-7.9, 4-chlorophenoxyacetic acid was found not to be significantly adsorbed to clay(2). Sorption of 4-chlorophenoxy acetic acid to clay is pH dependent and increases with decreasing ionization(3). Using a structure estimation method based on molecular connectivity indices(4), the Koc for 4-chlorophenoxy acetic acid can be estimated to be 18(SRC). According to a classification scheme(5), this estimated Koc value suggests that 4-chlorophenoxy acetic acid is expected to have very high mobility in soil(SRC). In addition, the pKa of 4-chlorophenoxy acetic acid is 3.56(6), indicating that this compound will primarily exist as an anion in the environment, and anions generally possess high mobility in soil(7).

The pKa of 4-chlorophenoxyacetic acid is 3.56(1), indicating that this compound will exist predominantly as an anion under environmental conditions. Volatilization will not occur from water and moist soils since anions do not volatilize(SRC). 4-Chlorophenoxyacetic acid is not expected to volatilize from dry soil surfaces(SRC), based upon an estimated vapor pressure of 3.2X10-4 mm Hg at 25 °C(SRC), determined from a fragment constant estimation method(2).

DRINKING WATER: 4-Chlorophenoxyacetic acid was qualitatively detected in treated drinking water supplies in the U.K.(1).

Occupational exposure to 4-chlorophenoxyacetic acid may occur by inhalation or dermal contact during its production or application as a plant growth regulator(SRC). Products containing 4-chlorophenoxyacetic acid are intended primarily for commercial use and are not likely to be used at residential sites; therefore, exposure to the general population is expected to be low(1).

Translocation and metabolism of (14)C-labeled phenoxyacetic acid in soybeans were evaluated following applications at 3 different sites, primary leaf, cotyledon, and epicotyl. 4-chlorophenoxyacetic acid was phloem-mobile compound 63.4% of the parent acid remained after 2 days. The factor which accounted for the difference between phloem transport of (14)C phenoxyacetic acid and the hormone-type compound is binding to receptor protein. (14)C phenoxyacetic acid appears to be more phloem mobile because it is not inactivated at the source, in the transport path, or at the sinks either by rapid and extensive in vivo degradation or by binding to plant growth regulator receptor proteins.|The differential renal excretion of phenoxyacetic acid, 2-chlorophenoxyacetic acid, 4-chlorophenoxyacetic acid, and herbicides 2,4-D and 2,4,5-T was measured in chickens by the method of Sperber (1948 and 1954). Doses of approximately 50 and 100 mumol of either test compound were infused during 3 min into a leg vein and the amounts excreted by the 2 kidneys determined during consecutive 15-min periods. At the lower dose level the mean apparent tubular excretion fractions (EF) of the compounds, expressed as per cent of the dose, where 16.5, 22.9, 12.8, 11.3 and 4.2, respectively. All the values except that for 2,4,5-T are sufficiently high to be indicative of tubular excretion. On increasing the dose, the EF values decreased, thus suggesting the involvement of a saturable mechanism. The test compounds depressed the excretion of phenol red, the effect being most marked with 2,4,5-T.|Tritiated chlorphenesin carbamate was quickly absorbed by the dog, with peak blood levels appearing 2-3 hr after injection. One of the urinary metabolites was p-chlorophenoxyacetic acid.

Soil microorganisms metabolize the herbicide p-chlorophenoxyacetic acid into 2-hydroxy-4-chlorophenoxyacetic acid, and Aspergillus niger converts phenoxyacetic acid into the o- and p-hydroxy derivatives.|A pseudomonas, capable of utilizing 4-CPA as a sole carbon source, was isolated from soil. The following compounds were identified in culture extracts: 4-chloro-2-hydroxyphenoxyacetate, 4-chlorocatechol, beta-chloromuconate, gamma-carboxyethylene-delta-alpha-beta-butenolide. It was found that beta-chloromuconolactone was unstable in aqueous solution and hydrolyzed easily to the corresponding beta-hydroxy analog.|Yields p-chlorophenol in arthrobacter. /from table/|Microbial degradation of various pesticides by aquatic and soil microorganisms was studied. Arthrobacter species metabolized 4-chlorophenoxyacetic acid to 4-chloro-3-hydroxyphenyl acetic acid.|For more Metabolism/Metabolites (Complete) data for 4-CHLOROPHENOXYACETIC ACID (6 total), please visit the HSDB record page.

Reagent grade p-chlorophenoxyacetic acid was found to contain 2,4-D as an impurity (1.0%) as well as traces of 2,4-dichlorophenols.

If any symptoms of illness occur during or following inhalation of spray, remove victim from contact with the material for at least 2 to 3 days. Allow subsequent contact with chlorophenoxy compounds only if effective respiratory protection is practiced. /Chlorophenoxy compounds/|Flush chemicals from eyes with copious amounts of clean water for 10 to 15 minutes. If irritation persists, an ophthalmologic examination should be performed. If substantial amounts of chlorophenoxy compounds have been ingested, spontaneous emesis may occur. ...Administer intravenous fluids to accelerate the excretion of chlorophenoxy compounds, 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 and cells, BUN, serum creatinine, serum electrolytes, and fluid intake/output carefully to ensure that renal function remains unimpaired and that fluid overload does not occur. /Chlorophenoxy compounds/|If ... ingested, spontaneous emesis usually occurs. Ordinarily, this empties the stomach as effectively as intubation & lavage. If vigorous emesis has not occurred, measures should be taken to empty the stomach and limit gastrointestinal absorption by gastric intubation, aspiration, and lavage, following placement of a cuffed endotracheal tube. Repeated administration of charcoal at half or more the original dosage every 2-4 hours may be beneficial. If gastric aspiration and lavage is not performed due to delay in treatment, and if the patient is fully alert, administer charcoal, and laxative orally. /Chlorophenoxy compounds/|Forced alkaline diuresis has been used successfully in management of suicidal ingestions of chorophenoxy compounds, especially when initiated early. Alkalinizing the urine by adding 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 as needed to offset 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 monitored carefully as the chlorophenoxy compound is excreted. Renal failure has occured in patients with severe intoxication during alkaline diuresis. ... /Chlorophenoxy compounds/|For more Antidote and Emergency Treatment (Complete) data for 4-CHLOROPHENOXYACETIC ACID (8 total), please visit the HSDB record page.

4-chlorophenoxyacetic acid

Marks 4-CPA, Tomato Fix concentrate, Tomato Hold, Tomatotone|Technical grade contains 4-chloro-o-cresol (<34%).|Aerosol, liquid, tablet.|... Aerosol spray in either a 2 or 0.005% solution.

Acetic acid, 2-(4-chlorophenoxy)-: ACTIVE|SPRAY APPLICATION OF 4-CHLOROPHENOXYACETIC ACID (2 AND 4 PPM) TO GRAPES INCREASED BERRY SET SIGNIFICANTLY OVER CONTROLS. BERRY SET INCREASED WITH INCREASE IN 4-CHLOROPHENOXYACETIC ACID CONCN. BERRY DROP WAS ALSO SIGNIFICANTLY REDUCED, AND WITH INCREASED AUXIN CONCN CORRESPONDING DECREASE IN BERRY DROP WAS OBSERVED. PANICLE DRYING WAS SEVERE IN THIS CULTIVAR WHICH WAS EFFECTIVELY REDUCED BY AUXIN APPLICATION.|THE EFFECT OF P-CHLOROPHENOXYACETIC ACID ON THE GROWTH, FLOWERING AND YIELD ON THE BITTER GOURD WAS STUDIED. 4-CHLOROPHENOXYACETIC ACID AT 100 PPM MARKEDLY IMPROVED PLANT GROWTH.|WHEN 1-3 PPM 4-CHLOROPHENOXYACETIC ACID WERE SPRAYED ON FOLIAGE AT THE STAGE OF THE 2ND NET FORMATION OF MUSKMELON FRUITS, FRUIT WT INCR BY 104-115% WITH GOOD NET FORMATION.|4-CHLOROPHENOXYACETIC ACID INHIBITS ABSCISSION OF STEM PARTS (BUTTONS) FROM FRUIT OF LEMON (CITRUS LIMON) STORED IN CONTROLLED ETHYLENE (ABOUT 5 PPM) ATMOSPHERE. FRESHLY PICKED LEMONS WERE DIPPED IN AQ SOLN CONTAINING 500 PPM TRITON X-100 AND THE ABOVE CMPD, AND WERE STORED FOR 13 DAYS AND ANALYZED FOR BUTTON ABSCISSION.|For more General Manufacturing Information (Complete) data for 4-CHLOROPHENOXYACETIC ACID (7 total), please visit the HSDB record page.

NUMEROUS METHODS HAVE BEEN DEVELOPED FOR THE ANALYSIS OF PHENOXY HERBICIDES INCLUDING 4-CPA. TECHNIQUES CONSIDERED ARE COLORIMETRY/SPECTROPHOTOMETRY, BIOASSAY, PAPER CHROMATOGRAPHY, TLC, GC AND MS.

Agrochemicals -> Plant Growth Regulators