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. /2,4-D esters/
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. /SRP: 2,4-D OR ITS ESTERS/
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/
Classification of carcinogenicity: 1) evidence in humans: limited; overall summary evaluation of carcinogenic risk to humans is Group 2B: The agent is possibly carcinogenic to humans. /SRP: The older literature indicated that these compounds were carcinogenic. It was discovered that this was due to contamination, including dioxin./ /Chlorophenoxy herbicides; From table/
来源:Hazardous Substances Data Bank (HSDB)
毒理性
副作用
职业性肝毒素 - 第二性肝毒素:在职业环境中的毒性效应潜力是基于人类摄入或动物实验的中毒案例。
Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.
来源:Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Cutthroat trout (Salmo clarki) were treated with six different paired mixtures of dicamba, picloram, 2,4-D butyl ester, 2,4-D isooctyl ester, and 2,4-D propylene glycol butyl ether ester. Except for 2,4-D isooctyl ester, the LC50's resulting from mixtures of 2,4-D esters and picloram were lower than LC50's of those herbicides tested individually. Dicamba and 2,4-D isooctyl ester were the least toxic individually and mixtures of dicamba or 2,4-D isooctyl ester with the other herbicides tested did not result in increased toxicity. Results reflect the importance of using combination exposures in determining the biological significance of the simultaneous occurrence of more than one herbicide in surface waters.
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/
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 or its esters/
Plasma 2,4-D concn did not exceed 0.2 mg/l in workers exposed to 2,4-D ester at an atmospheric concn of 0.1 to 0.2 mg/l; no accumulation was noted during the work week. ... Workers ... developed 2,4-D urine concentrations of 3 to 14 mg/l after a day of exposure. /2,4-Dichlorophenoxyacetic acid or its esters/
AFTER SC INJECTION OF 2,4-D & ITS BUTYL & ISOOCTYL ESTERS INTO MICE @ 100 MG/KG, ESTERS WERE ELIM RAPIDLY, & ONLY 5-10% OF THE 2,4-D REMAINED AFTER 1 DAY. ... 2,4-D WAS ELIM IN MILK OF COWS MAINTAINED IN PASTURES TREATED WITH 2,4-D OR ITS BUTYL OR ISOOCTYL ESTER.