Dicapthon

log Kow= 3.58 at 20 °C

3.44

CRYSTALS FROM METHANOL

WHITE SOLID FROM METHANOL

SOL IN ACETONE, CYCLOHEXANONE, ETHYL ACETATE, TOLUENE, XYLENE, ETHYLENE GLYCOL, PROPYLENE GLYCOL, SOME OILS; PRACTICALLY INSOL IN WATER

SOL IN CYCLOHEXANE

Water solubility= 14.7 mg/l at 20 °C

0.0000036 [mmHg]

3.6X10-6 mm Hg

Danger

H301 (100%): Toxic if swallowed [Danger Acute toxicity, oral]

P262, P264, P270, P280, P301+P316, P302+P352, P316, P321, P330, P361+P364, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 39 reports by companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

A cholinesterase inhibitor; [Hawley] The only adverse effect noted in one year feeding study with rats (250 ppm highest dose group) was retarded growth; [HSDB] The average of two baseline respective cholinesterase activity determinations three days apart, with no exposures to enzyme inhibiting pesticides for at least 30 days, is recommended for each worker prior to exposure to cholinesterase inhibitors because of large inter-individual differences in published baseline values. To be established at least once a year. Removal from workplace exposures is recommended until the cholinesterase activity returns to within 20% of baseline. [TLVs and BEIs]

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA, as amended in 1988, were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern and List D pesticides of less concern. O-(2-Chloro-4-nitrophenyl) O,O-dimethyl phosphorothioate is found on List B. Case No: 2785; Pesticide type: insecticide; Case Status: No products containing the pesticide are actively registered ... The case /is characterized/ as "cancelled." Under FIFRA, pesticide producers may voluntarily cancel their registered products. EPA also may cancel pesticide registrations if registrants fail to pay required fees or make/meet certain reregistration commitments, or if EPA reaches findings of unreasonable adverse effects.; Active ingredient (AI): O-(2-Chloro-4-nitrophenyl) O,O-dimethyl phosphorothioate; AI Status: The active ingredient is no longer contained in any registered pesticide products ... "cancelled."

Biological Exposure Indices (BEI) [ACGIH] - Acetylcholinesterase activity in red blood cells = 70% of individual's baseline; Butylcholinesterase activity in serum or plasma = 60% of individual's baseline; Sample at end of shift; [TLVs and BEIs]

... GREAT CARE SHOULD BE EXERCISED IN HANDLING ... WHEN SPRAYING & DUSTING ... CONTAMINATED CLOTHING SHOULD BE CHANGED FREQUENTLY. /ORGANOPHOSPHATE INSECTICIDES/

If material not on fire and not involved in fire: Keep sparks, flames, and othersources of ignition away. Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Use water spray to knock-down vapors. /Organophosphorus pesticides, liquid, NOS/

Personnel protection: Keep upwind. Wear appropriate chemical protective gloves, boots and goggles. Do not handle broken packages unless wearing appropriate personal protective equipment. Wear positive pressure self-contained breathing apparatus when fighting fires involving this material. /Organophosphorus pesticides, liquid, NOS/

If material not on fire and not involved in fire: Keep sparks, flames, and othersources of ignition away. Keep material out of water sources and sewers. /Organophosphorus pesticides, solid, NOS/

Personnel protection: Avoid breathing dusts, and fumes from burning material. Keep upwind. Avoid bodily contact with the material. Wear appropriate chemical protective gloves, boots and goggles. Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water. Wear positive pressure self-contained breathing apparatus when fighting fires involving this material. If contact with the material anticipated, wear appropriate protective clothing. /Organophosphorus pesticides, solid, NOS/

TERRESTRIAL FATE: Since dicapthon hydrolyzes in water(1), it will likely hydrolyze in moist soil(SRC); at 20 °C, aqueous hydrolysis half-lives of 49 days (pH 6.1) and 29 days (pH 7.4) have been determined(1); hydrolysis increases with alkalinity, so the degradation rate of dicapthon in soil will probably increase with alkalinity(SRC). In one soil persistence study (soil pH 6.2), dicapthon had a soil half-life of 43 days in sealed vials(1). Insufficient data are available to access the relative importance of biodegradation in soil. Based upon Koc estimates ranging from 865 to 2100(2-3,SRC), dicapthon is expected to have low mobility in soil(4,SRC).

AQUATIC FATE: Dicapthon can degrade in water through aqueous hydrolysis; at 20 °C, hydrolysis half-lives of 49 days (pH 6.1) and 29 days (pH 7.4) have been determined(1); the hydrolysis rate increases as the pH increases. Insufficient data are available to access the relative importance of biodegradation or photodegradation in water. Based upon Koc estimates ranging from 865 to 2100(2-3,SRC), some partitioning from the water column to sediment and suspended material may occur(SRC). Aquatic volatilization is not expected to be an important fate process(SRC).

ATMOSPHERIC FATE: Based upon a reported vapor pressure of 3.6X10-6 mm Hg at 20 °C(1), dicapthon can exist in both the vapor and particulate phases in the ambient atmosphere(2,SRC). It will degrade rapidly in the vapor phase by reaction with photochemically produced hydroxyl radicals with an estimated half-life of about 6 hr(3,SRC). Particulate phase dicapthon and aerosols released to air during applications of dicapthon insecticides will be removed from air physically by dry and wet deposition(SRC).

Based upon a measured log Kow of 3.58(1) and a water solubility of 14.7 mg/l at 20 °C(2), the Koc of dicapthon can be estimated to be 2100 and 995, respectively, from regression derived equations(3,SRC). Using a structure estimation method(4), the Koc can be estimated to be 865(4,SRC). According to a suggested classification scheme(5), these estimated Koc values suggest that dicapthon has low mobility in soil(SRC).

Symptomatology: 1. Nausea ... vomiting, abdominal cramps, diarrhea, excessive salivation ... 2. Headache, giddiness, vertigo & weakness. 3. Rhinorrhea & sensation of tightness in chest are common in inhalation exposure. 4. Blurring or dimness of vision, miosis ... . Tearing, ciliary muscle spasm, loss of accommodation & ocular pain ... . Mydriasis ... sometimes seen ... probably due to sympatho-adrenal discharge. 5. Bradycardia or tachycardia. Varying degrees of AV heart block are described, as well as atrial arrhythmias. 6. Loss of muscle coordination, slurring of speech, fasciculations & twitching of muscles (particularly of tongue & eyelids, & generalized profound weakness. 7. Mental confusion, disorientation & drowsiness. /Parathion/

Symptomatology: 8. Difficulty in breathing, excessive secretion of saliva & of resp tract mucus, oronasal frothing, cyanosis, pulmonary rales & rhonchi & hypertension (presumably due to asphyxia). 9. Random jerky movements, incontinence, convulsions, & coma. 10. Death primarily due to resp arrest arising from failure of resp center, paralysis of resp muscles, intense bronchoconstriction or all three. /Parathion/

... Dicapthon was tested for safety and for its ability to control malaria mosquitoes. The 50% water-wettable powder was applied as a 5% suspension of active ingredient at a rate of 2 g/sq m to the inside of 219 homes and 262 other structures. The buildings had mud walls and thatch roofs. The workers wore waterproof hats, rubber gloves, shoes, and overalls that were washed daily. Workers who weighed out individual pump charges into bags wore respirators in addition to the other protective equipment. No complaints attributable to dicapthon were received from either the workers or from the inhibitants of sprayed houses. Whole blood cholinesterase activity was slightly depressed in the workers but not in the inhabitants ... .

Cholinesterase inhibitor

Using a flow-through system and a 3-11 day exposure period,a dicapthon BCF (extractable lipid basis) of 891 was measured in guppy fish (Poecilia reticulata)(1). Based upon a measured log Kow of 3.58(2) and a water solubility of 14.7 mg/l at 20 °C(3), the BCF of dicapthon can be estimated to be 310 and 136, respectively, from regression derived equations(4,SRC). These BCF values suggest that some bioconcentration may occur in aquatic organisms(SRC).

Based upon a vapor pressure of 3.6X10-6 mm Hg(1) and a water solubility of 14.7 mg/L at 20 °C(2), the Henry's Law constant for dicapthon can be estimated to be 9.59X10-8 atm-cu m/mole (SRC). This value of Henry's Law constant indicates that dicapthon is essentially nonvolatile from water(3).

OF COMPARATIVELY LOW MAMMALIAN TOXICITY ... RATS MAINTAINED FOR 1 YR ON DIETS CONTAINING 25, 100 & 250 PPM SHOWED RETARDED GROWTH ONLY @ TWO HIGHER LEVELS. SKIN ABSORPTION APPARENTLY SLIGHT SINCE GUINEA PIGS WERE UNAFFECTED BY SINGLE APPLICATION OF 18 HR DURATION OF 2 G/KG.

LETHAL AMT OF ORGANOPHOSPHATES CAUSE DEATH BY COMBINATION OF EFFECTS OF MUSCARINIC, NICOTINIC & CENTRAL CHOLINERGIC OVERSTIMULATION &/OR RECEPTOR PARALYSIS. THUS HYPOTENSION, BRADYCARDIA, BRONCHOCONSTRICTION & BRONCHIAL FLUID ACCUMULATION, INABILITY OF TONICALLY RIGID ... RESP MUSCLES TO WORK PROPERLY, CYANOSIS, & CENTRAL RESPIRATORY DEPRESSION ARE MANIFESTED. THE ANIMAL DIES OF ASPHYXIA. /ORGANOPHOSPHATES/

ANTICHOLINESTERASES MAY EXERT DEPRESSANT ACTION ON CONDITIONED BEHAVIOR. LOWER DOSES MAY PRODUCE STIMULATION, HIGHER DOSES DEPRESSION. CHLORTHION RECORDED TO HAVE DEPRESSANT EFFECT ON CONDITIONED BEHAVIOR.

The rate constant for the vapor phase reaction of dicapthon with photochemically produced hydroxyl radicals has been estimated to be 6.1X10-11 cu cm/molecule-sec at 25 °C which corresponds to an atmospheric half-life of about 6 hours at an atmospheric concn of 5X10+5 hydroxyl radicals per cu cm(1,SRC). At 20 °C, the aqueous hydrolysis half-life of dicapthon in phosphate buffered solution was experimentally determined to be 29 days at pH 7.4 and 49 days at pH 6.1(2).

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA, as amended in 1988, were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern and List D pesticides of less concern. O-(2-Chloro-4-nitrophenyl) O,O-dimethyl phosphorothioate is found on List B. Case No: 2785; Pesticide type: insecticide; Case Status: No products containing the pesticide are actively registered ... The case /is characterized/ as "cancelled." Under FIFRA, pesticide producers may voluntarily cancel their registered products. EPA also may cancel pesticide registrations if registrants fail to pay required fees or make/meet certain reregistration commitments, or if EPA reaches findings of unreasonable adverse effects.; Active ingredient (AI): O-(2-Chloro-4-nitrophenyl) O,O-dimethyl phosphorothioate; AI Status: The active ingredient is no longer contained in any registered pesticide products ... "cancelled."

RABBIT & RAT LIVER MICROSOMES & HOUSEFLY MICROSOMES PLUS NADPH2 & O2 WERE INCUBATED WITH DICAPTHON. IN EACH CASE, CORRESPONDING PHENOL WAS FOUND. ACTIVATION OF DICAPTHON TO CORRESPONDING OXON ANALOG WAS OBSERVED. SOME CONVERSION OF OXON ANALOG TO CORRESPONDING PHENOL WAS ALSO OBSERVED ... .

YIELDS 2-CHLORO-4-NITROPHENOL IN RAT, IN RABBIT, IN FLY. YIELDS 2-CHLORO-4-NITROPHENYL DIMETHYL PHOSPHATE IN RAT, IN RABBIT, IN FLY. /FROM TABLE/

A relatively high proportion of the total metabolism in the rat involves alkyl phosphate hydrolysis, as is true of other dialkyl compounds, in contrast to diethyl compounds.

/ORGANOPHOSPHORUS INSECTICIDES/ ... ARE ABSORBED INTO BODY BY RESPIRATORY, GASTROINTESTINAL, & CUTANEOUS PATHWAYS. /ORGANOPHOSPHORUS INSECTICIDES/

IN GENERAL, BECAUSE OF RAPID HYDROLYSIS & EXCRETION IN URINE, ORGANOPHOSPHORUS COMPD ARE NOT ACCUMULATED & STORED IN ANIMAL BODY. /ORGANOPHOSPHORUS COMPD/

Used as insecticide and acaricide for agricultural, household, and public health pest control; Also used for tick control in domestic animals; [HSDB]

Cancelled--no longer registered as a pesticide for use in the US; [HSDB]

Farming (Pesticides) [Category: Industry]

The active ingredient is no longer contained in any registered pesticide products ... "cancelled."

INSECTICIDE

Aphicide

PRODUCTION DISCONTINUED BY AMERICAN CYANAMID CO.

... DICAPTHON ... /IS USED/ IN HOUSEHOLD, PUBLIC HEALTH, & AGRICULTURAL PEST CONTROL.

OF PROMISING INSECTICIDAL ACTIVITY GIVING OVER 90% KILL OF APHID @ CONCN OF 1:28000 IN WATER; EFFECTIVE AGAINST BOLL WEEVIL WITH GOOD RESIDUAL ACTIVITY.

EMPLOYED TO CONTROL TICKS ON DOGS & OTHER DOMESTIC ANIMALS.