141-66-2

A yellow to brown liquid with a mild ester odor. Used to control sucking, boring, and chewing pests on rice, cotton, coffee, apples, and other crops. Effective on ornamentals, trees, and shrubs for aphids, leaf hoppers, and scale insects.

Organophosphates, such as DICROTOPHOS(141-66-2), are susceptible to formation of highly toxic and flammable phosphine gas in the presence of strong reducing agents such as hydrides. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides. This compound is incompatible with the following: Metals [Note: Corrosive to cast iron, mild steel, brass & stainless steel.] .

Water soluble.

DICROTOPHOS is extremely toxic. Probable human oral lethal dose is 5 to 50 mg/kg, 7 drops to one teaspoonful for a 70 kg (150 lb.) person. Closely related in toxicity to azodrin.

A potential danger to those involved in the manufacture, formulation and application of this organophosphate. Used to control the coffee borer and certain economically important pests of cotton

(Non-Specific--Organophosphorus Pesticide, Liquid, n.o.s.) This material may burn but does not ignite readily. Container may explode in heat of fire. Fire and runoff from fire control water may produce irritating or poisonous gases. Rapidly hydrolyzes in acid or alkali. Keep away from heat and open flame.

If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 15 minutes, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin, remove contaminated clothing and wash immediately with soap and water. Speed in removing material from skin is of extreme importance. Shampoo hair promptly if contaminated. Seek medical attention immediately. If this chemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. Medical observation is recommended; effect may be delayed.

UN3018 Organophosphorus pesticides, liquid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.

Attacks some metals: Corrosive to cast iron, mild steel; brass, and stainless steel l304. Decomposes after prolonged storage, but is stable when stored in glass or polyethylene containers with temperatures to 40C. Contact with oxidizers may cause the release of phosphorous oxides. Contact with strong reducing agents, such as hydrides, may cause the formation of flammable and toxic phosphine gas

It is a yellowish liquid, bp 130 ?C/0.1 mmHg, vp 9.3 mPa (20 ?C). It ismiscible with water and most organic solvents except kerosene. Log Kow = ?0.5. Dicrotophos is rather stable to heat and slowly hydrolyzed in acidic media and more rapidly in alkaline media; DT₅₀ (20 ?C) at pH 5, 7, and 9 are 88, 72, and 28 d, respectively.

Dicrotophos is an amber liquid with a mild ester odor.

Dicrotophos decomposes after 7 days @ 90C and 31 days @ 75°C. Hydrolysis is 50% complete in aqueous solutions @ 38C after 50 days at pH 9.1 (100 days are required at pH 1.1). Alkaline hydrolysis (NaOH) yields (CH3)2NH. Incineration is also recommended as a disposal method. In accordance with 40CFR165, follow recommendations for the disposal of pesticides and pesticide containers. Must be disposed properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office

Contact and systemic insecticide and acaricide used to control pests on rice, cotton, maize, soybeans, coffee, citrus and potatoes.

Dicrotophos is used to control sucking, chewing and boring insects and mites in a wide range of crops. It is also used as an animal ectoparasiticide.

ChEBI: Dicrotophos is a dialkyl phosphate and an organophosphate insecticide. It has a role as an EC 3.1.1.7 (acetylcholinesterase) inhibitor, an acaricide, an avicide and an agrochemical.

Dicrotophos is synthesized by the Perkow reaction from trimethyl phosphite and N,N-dimethyl-α- chloroacetoacetamide, consisting mainly of the (E)-form.

Insecticide, Acaricide: EPA restricted Use Pesticide (RUP). Not approved for use in EU countries. Dicrotophos was introduced in 1956 as a contact systemic pesticide with a wide range of applications. Today, dicrotophos is currently used mainly as an insecticide for apples and other fruit crops, and for cotton pests, mostly in the Mississippi Valley. It is acutely toxic to birds, especially those that follow their migratory corridors and feed in the farmlands that have been treated with this pesticide. Internationally, dicrotophos is used on rice, coffee and citrus. One of the major degradates of dicrotophos is monocrotophos. All uses of monocrotophos have been voluntarily cancelled in the United States due to its extreme toxicity to humans and wildlife

BIDIRL®; BIDRIN®; BIDRIN-R®[C]; BIDRIN®[C]; C-709®; C-709®; CARBICRIN®; CARBICRON®; CARBOMICRON®; CIBA 709®; DIAPADRIN®; DICRON®; DIDRIN®; EKTAFOS®; EKTOFOS®;

When rats were fed dicrotophos in their diets at concentrations of 0, 1, 10, or 100 ppm for 2 years, there were no detectable effects at the 1 ppm concentration . Plasma cholinesterase was inhibited at 1 ppm . At 10 and 100 ppm, decreased body weights and reduced cholinesterase (erythrocyte, plasma, and brain not specified) activities occurred. Dogs given dicrotophos in their diets at 0, 0.16, 1.6, or 16 ppm for 2 years showed some instances of slightly excessive salivation . At 16 ppm, both plasma and RBC cholinesterase activity was decreased.

Soil. The dimethylamino group is converted to an N-oxide then to -CH2OH and aldehyde groups which further degrade via demethylation and hydrolysis (Hartley and Kidd, 1987). Dicrotophos is rapidly degraded under aerobic and anaerobic conditions forming N,N-dimethylacetoacetamide and 3-hydroxy-N,N-dimethylbutyramide as the major metabolites. Other metabolites included carbon dioxide and unextractable residues. The half-life of dicrotophos in a Hanford sandy loam soil was 3 days (Lee et al., 1989).Biological. Identified metabolites of dieldrin from solution cultures containing Pseudomonas sp. in soils include aldrin and dihydroxydihydroaldrin. Other unidentified byproducts included a ketone, an aldehyde and an acid (Matsumura et al., 1968; Kearney and Kaufman, 1976). A pure culture of the marine alga, namely Dunaliella sp., degraded dieldrin to photodieldrin and an unknown metabolite at yields of 8.5 and 3.2%, respectively.
Chemical/Physical. Dicrotophos emits toxic fumes of phosphorus and nitrogen oxides when heated to decomposition (Sax and Lewis, 1987; Lewis, 1990).
Dicrotophos is hydrolyzed in sodium hydroxide solutions forming dimethylamine. The hydrolysis half-lives at 38°C and pH values of 1.1 and 9.1 are 100 and 50 days, respectively (Sittig, 1985). Lee et al. (1989) reported that the hydrolysis half-lives of di

The metabolic fate of dicrotophos mirrors very closely that of its close congener, monocrotophos. Technical dicrotophos contains 82% of the E-isomer and 6% of the Z-isomer, the balance being various impurities. Most studies on the metabolic fate of this compound have used a purified material containing >99% E-isomer. Dicrotophos is a systemic vinyl phosphate insecticide with a high water solubility and low log Kow.
The main routes of metabolic degradation are demethylation to des- O-methyldicrotophos and hydrolysis to dimethyl phosphate and N,N-dimethylacetoacetamide. In animals and plants, hydroxylation of the N-methyl group followed by N-demethylation are also important from a toxicological point of view, since these metabolic steps yield highly active idubitors of acetylcholinesterase. In the case of dicrotophos, N-demethylation affords monocrotophos as one of the products of metabolism.

The main degradation routes are O-demethylation to des-O-methyldicrotophos and hydrolysis to dimethyl phosphate and N,N-dimethylacetoacetamide. Oxidative Ndemethylation also occurs.

Color Code—Blue: Health Hazard/Poison: Storein a secure poison location. Prior to working with thischemical you should be trained on its proper handling andstorage. Store in tightly closed containers in a cool, wellventilated area away from strong oxidizers, metals, strongbases, and heat. Where possible, automatically pump liquidfrom drums or other storage containers to processcontainers.

Dicrotophos is relatively stable at acidic and neutral pH values but it is hydrolysed in alkaline solutions (PM). The DT₅₀s at pH 5, 7 and 9 (25 °C) were 117, 72 and 28 days, respectively. The products of hydrolysis, which were identified by GC of their methyl esters, were N,N-dimethylacetoacetamide (2), the main product at alkaline pH values, and des-O-methyldicrotophos (3), which predominated in acid and neutral solutions (Lee ef al., 1989). Further decomposition of N,N-dimethylacetoacetamide (2) under alkaline conditions then gave acetone (4), CO2 and dimethylamine (5), whereas under acidic conditions the des-O-methyldicrotophos (3) was shown to decompose to inorganic phosphate (6), monomethyl phosphate (7), methanol (8), acetone (4) and N,N-dimethylacetoacetamide (2) (Brown et al., 1966). Dicrotophos is not subject to photodecomposition. Photolysis experiments in which aqueous solutions of monocrotophos were exposed to simulated sunlight (xenon arc lamp) in quartz tubes showed no products other than the hydrolysis products 2 and 3, neither was their rate of formation accelerated. A soil surface photolysis experiment indicated some small loss of dicrotophos,probably as CO2 due to microbial action. No particular photolytic degradation products were detected apart from minor amounts of the hydrolysis products 2 and 3. After 30 days 80% of the dicrotophos was recovered unchanged. Residual metabolites which were unextractable from the soil were not generated by photodegradation, since a dark control experiment produced the same proportion of unextractable material (Lee et al., 1989) (see Scheme 1).

The acute oral LD₅₀ for rats is 17–22 mg/kg. Inhalation LC50 (4 h) for rats is about 0.09 mg/L air. NOEL in a three-generation reproduction study with rats is 2 mg/kg daily. In mammals, orally administered dicrotophos is rapidly metabolized, and 63–71% was excreted in the urine within 48 h.