Name | 2,4-Dichlorophenoxyacetic acid |
Synonyms | For 2,4-D u-5043 ipaner Estone dicopur Ferxone amoxone dormone dicotox bh 2,4-d weed tox crotilin decamine agrotect weedtrol Fernimine 2,4-d lv6 Fernoxone envert dt netagrone pennamine weedar 64a Foredex 75 chloroxone 2,4-D Acid helena 2,4-d b-selektonon Farmon 2,4-d emulsamine bk Esterone four weedone-2,4-dp dichloro(phenoxy)acetic acid 2,4-Dichlorophenoxyacetic acid 2,4-Dichlorophenoxy Acetic Acid |
CAS | 94-75-7 |
EINECS | 202-361-1 |
InChI | InChI=1/C8H6Cl2O3/c9-8(10,7(11)12)13-6-4-2-1-3-5-6/h1-5H,(H,11,12) |
Molecular Formula | C8H6Cl2O3 |
Molar Mass | 221.04 |
Density | 1.563 |
Melting Point | 136-140 °C (lit.) |
Boling Point | 160 °C (0.4 mmHg) |
Flash Point | 160°C/0.4mm |
Water Solubility | Slightly soluble. Decomposes. 0.0890 g/100 mL |
Solubility | Soluble in organic solvents (ethanol, acetone, dioxane) |
Vapor Presure | 0.4 mm Hg ( 160 °C) |
Appearance | crystalline |
Color | off-white to tan |
Exposure Limit | NIOSH REL: TWA 10 mg/m3, IDLH 100 mg/m3; OSHA PEL: TWA10 mg/m3; ACGIH TLV: TWA 10 mg/m3. |
Merck | 14,2796 |
BRN | 1214242 |
pKa | pK1:2.64 (25°C) |
Storage Condition | 2-8°C |
Stability | Stable, but moisture-sensitive and may be light-sensitive. Incompatible with strong oxidizing agents, corrodes many metals. Decomposes in water. |
Refractive Index | 1.5000 (estimate) |
Physical and Chemical Properties | Density 1.563 melting point 137-141°C boiling point 160°C (0.4 torr) water-soluble sudden solution. Decomposes. 0.0890g/100 mL |
Use | Used as plant growth regulator |
Risk Codes | R22 - Harmful if swallowed R37 - Irritating to the respiratory system R41 - Risk of serious damage to eyes R43 - May cause sensitization by skin contact R52/53 - Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment. R39/23/24/25 - R23/24/25 - Toxic by inhalation, in contact with skin and if swallowed. R36/37/38 - Irritating to eyes, respiratory system and skin. R11 - Highly Flammable R36 - Irritating to the eyes R20/21/22 - Harmful by inhalation, in contact with skin and if swallowed. R67 - Vapors may cause drowsiness and dizziness R66 - Repeated exposure may cause skin dryness or cracking |
Safety Description | S24/25 - Avoid contact with skin and eyes. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36/37/39 - Wear suitable protective clothing, gloves and eye/face protection. S46 - If swallowed, seek medical advice immediately and show this container or label. S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. S2 - Keep out of the reach of children. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S36/37 - Wear suitable protective clothing and gloves. S27 - Take off immediately all contaminated clothing. S16 - Keep away from sources of ignition. S7 - Keep container tightly closed. S9 - Keep container in a well-ventilated place. |
UN IDs | UN 3077 9/PG 3 |
WGK Germany | 2 |
RTECS | AG6825000 |
TSCA | Yes |
HS Code | 29189090 |
Hazard Class | 6.1 |
Packing Group | III |
Toxicity | LD50 (oral): rat [free] 375 mg/kg, [-Na] 666-805 mg/kg. |
pH range of acid-base indicator discoloration | Acidic |
olfactory Threshold | 3.13 ppm |
Henry's Law Constant | 6.72 and 0.84 x 10-5 atm?m3/mol were reported at pH values of 1 and 7, respectively (wetted-wall column, Rice et al.,1997a) |
(IARC) carcinogen classification | 2B (Vol. 113) 2018 |
NIST chemical information | information provided by: webbook.nist.gov (external link) |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
toxicity | LD50 (oral): rat [free] 375 mg/kg, [-Na] 666-805 mg/kg. |
usage limit | GB 2760-1996: fruits and vegetables fresh-keeping 0.01g/kg, residue ≤ 2.0mg/kg. FAO/WHO,1994: Citrus residues less than or equal to 2 mg/kg. |
Use | 2, 4-dichlorophenoxyacetic acid is used as a chemical antiseptic fungicide, which can be used for the preservation of vegetables and fruits, the maximum amount of 0.01g/kg, the residue is not more than 2.0mg/kg. 2, 4-difluorophenoxyacetic acid was used as a preservative for concentrate feed, and the maximum usage amount was 0.01g/kg. used as standard for organic analysis, herbicide and plant growth hormone used as plant growth regulator preservative. Can be used in combination with other disinfectants. Limited prevention of foot rot of citrus fruits. 2,4-D is the lowest level of selective and efficient organic herbicide in the world. Further, 2, 4-dichlorophenoxyacetic acid was also used as a reagent for the determination of thorium. herbicides, plant growth agents, organic microanalysis for the determination of carbon and hydrogen standards. |
production method | Firstly, 2, 4-dichlorophenol is obtained by chlorination of phenol, the latter is condensed with chloroacetic acid in the presence of sodium hydroxide to form 2,4-D sodium salt, which is then acidified to 2,4-D. Another new process is the condensation of phenol and chloroacetic acid under alkaline conditions, and then obtained by chlorination. Sodium 2, 4-dichlorophenoxyacetate is prepared by heating and refluxing 2, 4-dichlorophenol and monochloroacetic acid in NaOH solution, and then acidified with hydrochloric acid. with phenol as raw material, the product can be prepared by first condensation with chloroacetic acid and then chlorination, or first chlorination and then condensation with chloroacetic acid. (1) The first condensation after chlorination process. The phenol was placed in a reaction kettle, heated and melted, and 2.2-fold (molar ratio) sodium hydroxide and 1.2-fold (molar ratio) dichloroacetic acid were successively charged, and reacted at 100-110 ° C. For 30min. After cooling, the reactant was neutralized with hydrochloric acid, and phenoxyacetic acid was precipitated. The yield was more than 82%. Phenoxyacetic acid at 65-90 ° C, slowly introduced 1.4-1.6 times (molar ratio) Chlorine gas, the chlorinated product, I .e., 2, 4-difluorophenoxyacetic acid, yield 89%. (2) the condensation process after the first chlorination. The molten phenol was placed in a chlorinating apparatus, and the chlorination reaction was completed at 45-65 °c for about 8-9H when the relative density of the reaction mass reached 1.406(40 °c). The reaction was heated to 30% sodium hydroxide solution. After heating to boiling, sodium chloroacetate solution was added dropwise and refluxed for 4-5H. After being slightly chilled, it was neutralized to PH1-3 with 30% hydrochloric acid. Benzene was added while hot for extraction, and the organic layer was separated. White crystals were precipitated after cooling, and the product was obtained by Suction filtration and drying. with phenol as raw material, the product can be prepared by first condensation with chloroacetic acid and then chlorination, or first chlorination and then condensation with chloroacetic acid. After the first condensation and chlorination process, the phenol is placed in the reaction kettle, heated and melted, and 2.2 times (molar ratio) of sodium hydroxide and 1.2 times (molar ratio) of chloroacetic acid are successively input, the reaction was carried out at 100~110 ℃ for 30min. After cooling, the reactant was neutralized with hydrochloric acid, and phenoxyacetic acid was precipitated. The yield was more than 82%. Phenoxyacetic acid in 65~90 deg C, slowly through 1.4~1.6 times (molar ratio) of chlorine gas, the chlorinated product was 2, 4-dichlorophenoxyacetic acid, yield 89%. First chlorination and then condensation process the molten phenol is placed in a chlorinating apparatus, and the chlorine is passed at 45~65 ℃ for about 8~9H. When the relative density of the reaction mass reaches 1.406(40 ℃) at the end of the chlorination reaction. The reactants were added with 30% sodium hydroxide solution while hot, and after heating to boiling, sodium chloroacetate solution was added dropwise and refluxed for 4-5 hours. After cooling slightly, it was neutralized to pH 1-3 with 30% hydrochloric acid. Benzene was added while hot for extraction, and the organic layer was separated. White crystals were precipitated after cooling, and the product was obtained by Suction filtration and drying. |
category | pesticide |
toxicity grade | high toxicity |
Acute toxicity | oral-rat LD50: 375 mg/kg; Oral-mouse LD50: 347 mg/kg |
stimulation data | Skin-rabbits 500 mg/24 h mild; eye-rabbit 0.75 mg/24 h severe |
flammability hazard characteristics | flammable; Toxic chloride fumes from combustion |
storage and transportation characteristics | The warehouse is ventilated and dried at low temperature, separate storage of food additives |
fire extinguishing agent | foam, water, carbon dioxide, sand |
Occupational Standard | TLV-TWA 10 mg/m3; Tel 15 mg/m3 |
spontaneous combustion temperature | > 180°C |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |
immediate life-threatening and health concentration | 100 mg/m3 |