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Leptophos

Leptophos structure

Leptophos 

structure
  • CAS No:

    21609-90-5

  • Formula:

    C13H10BrCl2O2PS

  • Chemical Name:

    Leptophos

  • Synonyms:

    Phosphonothioic acid,P-phenyl-,O-(4-bromo-2,5-dichlorophenyl) O-methyl ester;Phosphonothioic acid,phenyl-,O-(4-bromo-2,5-dichlorophenyl) O-methyl ester;O-(4-Bromo-2,5-dichlorophenyl) O-methyl phenylphosphonothioate;VCS 506;Velsicol VCS 506;Velsicol 506;Phosvel;K62-105;Leptophos;Fosvel;NK 711;Abar;Oleophosvel;MBCP;(±)-Leptophos;73270-49-2

  • Categories:

    Agrochemicals  >  Insecticides

Description

Leptophos is a tan, waxy solid


Leptophos appears as white crystalline or colorless amorphous solid, the technical product is a light tan powder. Used as an insecticide; its use is not permitted in the U.S. (EPA, 1998)|Solid


Leptophos appears as white crystalline or colorless amorphous solid, the technical product is a light tan powder. Used as an insecticide; its use is not permitted in the U.S. (EPA, 1998)|An organothiophosphate insecticide.

Leptophos Basic Attributes

412.07

412.07

244-472-8

3464|3018

DTXSID3040279

WHITE CRYSTALLINE SOLID|COLORLESS AMORPHOUS SOLID|Tan waxy solid

2930909090

Characteristics

60.36000

6.06670

1.53 g/cm3 @ Temp: 25 °C

70.2-70.6 °C

444.4ºC at 760 mmHg

>100 °C

1.651

2.4mg/L(25 ºC)

0-6°C

Vapor pressure= 2.3X10-8 mm Hg at 20 deg C[Freed VH et al; Environ Health Perspect 20: 55-70 (1977)]

Oral-rat LD50: 19 mg/kg; Oral-Mouse LD50: 65 mg/kg

Open flame is flammable; heat releases toxic sulfur oxide, phosphorus oxide, halide gas

169.83 Ų [M+H]+

LIGHT TAN POWDER NOT LESS THAN 85% PURITY /TECHNICAL/|DECOMPOSES ABOVE 180 °C

No rapid reaction with air. No rapid reaction with water.

Sulfonates, Phosphonates, and Thiophosphonates, Organic

Organophosphates, such as LEPTOPHOS, 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.

Safety Information

II

6.1(a)

2783

3

21-25-39/25-50/53-36/37/38

25-36/37/39-45-60-61-23-36-26

TB1720000

T,N,Xi

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

STABLE TO ACIDS UNDER LONG EXPOSURE @ NORMAL TEMPERATURE, BUT IS SLOWLY HYDROLYZED UNDER STRONGLY ALKALINE CONDITIONS.

P260-P273-P307 + P311-P501

H301-H312-H370-H410

Potential candidate for rotary kiln incineration, with a temperature range of 820 to 1,600 °C and a residence time of seconds. Also, a potential candidate for fluidized bed incineration, with a temperature range of 450 to 980 °C, and a residence time of seconds. Also, a potential candidate for liquid injection incineration with a temperature range of 650 to 1,600 °C, and a residence time of 0.1 to 2 seconds. /Parathion/|The following wastewater treatment technologies have been investigated for parathion: Reverse osmosis. /Parathion/

BARLOW JN; TOXICOLOGY AND SAFETY EVALUATION OF PHOSVEL TO EGYPTIAN WATER BUFFALO. WATSON DL & AWA BROWN EDS, PESTICIDE MGMNT & INSECTICIDE RESISTANCE, XVTH INTERNATIONAL CONGRESS OF ENTOMOLOGY, SECTION ON PESTICIDE DEVELOPMENT, MGMNT & REGULATION, WASHINGTON, DC, AUG 20-27, (1976). TOXICOLOGY & SAFETY EVALUATION OF PHOSVEL TO EGYPTIAN WATER BUFFALO ARE REVIEWED.|WATERS EM, GERSTNER HB; LEPTOPHOS: AN OVERVIEW. LITERATURE COMPILATION, 1969-1979; REPORT ORNL/TIRC-78/4 (1979) 94. THE PHYSICAL & CHEMICAL PROPERTIES OF LEPTOPHOS, USE & MODE OF ACTION IN TARGET SPECIES, & METABOLISM & TOXICOLOGY IN THE VERTEBRATES ARE DISCUSSED.|CLEGG DJ; ANIMAL REPRODUCTION AND CARCINOGENICITY STUDIES IN RELATION TO HUMAN SAFETY EVALUATION; DEV TOXICOL ENVIRON SCI 4: 45 (1979). ANIMAL REPRODUCTION & CARCINOGENICITY STUDIES ARE REVIEWED WITH RESPECT TO THEIR USE IN EVALUATING THE SAFETY OF TOXIC CHEMICALS IN HUMANS.|Cherniack MG; Toxicological Screening for Organophosphorus-Induced Delayed Neurotoxicity: Complications in Toxicity Testing; Neurotoxicology 9 (2): 249-71 (1988). Organophosphorus induced delayed neurotoxicity was reviewed and discussed in relation to toxicological screening. Human cases of organophosphorus induced delayed neurotoxicity resulting from exposure to medicinal agents, leptophos, fenthion, and isophenphos were reviewed.

(Non-Specific -- Organophosphorus Pesticide, n.o.s.) Container may explode in heat of fire. Fire may produce irritating or poisonous gases. Decomposes above 356F. Avoid strong alkalies. (EPA, 1998)

|Danger|H301: Toxic if swallowed [Danger Acute toxicity, oral]|P260, P264, P270, P273, P280, P301+P310, P302+P352, P307+P311, P312, P321, P322, P330, P363, P391, P405, and P501|H301 (97.01%): Toxic if swallowed [Danger Acute toxicity, oral]|Aggregated GHS information provided by 134 companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H300: Fatal if swallowed [Danger Acute toxicity, oral]|P201, P202, P260, P261, P264, P270, P271, P280, P281, P301+P310, P302+P352, P304+P340, P305+P351+P338, P308+P313, P309+P311, P311, P312, P321, P322, P330, P337+P313, P361, P363, P403+P233, P405, and P501

Excerpt from ERG Guide 151 [Substances - Toxic (Non-combustible)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

(Non-Specific -- Organophosphorus Pesticide, n.o.s.) Stay upwind; keep out of low areas. Ventilate closed spaces before entering them. Do not touch spilled material; stop leak if you can do it without risk. Use water spray to reduce vapors. Small dry spills: with clean shovel place material into clean, dry container and cover; move containers from spill area. (EPA, 1998)

For emergency situations, wear a positive pressure, pressure-demand, full facepiece self-contained breathing apparatus (SCBA) or pressure- demand supplied air respirator with escape SCBA and a fully-encapsulating, chemical resistant suit. (EPA, 1998)|NEOPRENE COATED GLOVES; RUBBER WORKSHOES OR OVERSHOES; LATEX RUBBER APRON; GOGGLES; RESPIRATOR OR MASK APPROVED FOR TOXIC DUSTS & ORGANIC VAPORS. /PARATHION/|Employees should be provided with and required to use impervious clothing, gloves, face shields (eight inch minimum), and other appropriate protective clothing necessary to prevent repeated, or prolonged skin contact with parathion. /Parathion/|Respirator selection, upper limit devices recommended by NIOSH. For concn up to 0.5 mg/cu m use any chemical cartridge respirator with organic vapor cartridge(s) in combination with a dust, mist, and fume filter; or any supplied air respirator; or any self contained breathing apparatus. For concn up to 1.25 mg/cu m use any supplied air respirator operated in a continuous flow mode; or any powered air purifying respirator with organic vapor cartridge(s) in combination with a dust, mist and fume filter. For concn up 2.5 mg/cu m use any chemical cartridge respirator with a full facepiece and organic vapor cartridge(s) in combination with a high efficiency particulate filter; or any supplied air respirator with a full facepiece; or any self contained breathing apparatus with a full facepiece; or powered air purifying respirator with a high efficiency filter with an organic vapor cartridge; or any supplied air respirator with a tight fitting facepiece operated in a continuous flow mode. For concn up to 20 mg/cu m use any supplied-air respirator with a half-mask and operated in a pressure demand or other positive pressure mode. For emergency or planned entry in unknown concentration or IDLH conditions use any self contained breathing apparatus with a full facepiece and operated in a pressure demand or other positive pressure mode; or any supplied air respirator with a full face piece and operated in pressure demand or other positive pressure mode in combination with an auxiliary self contained breathing apparatus operated in pressure demand or other positive pressure mode. Escape: Any air purifying full facepiece respirator (gas mask) with a chin style or front or back mounted canister providing protection against the compound of concern; or any appropriate escape type self contained breathing apparatus. /Parathion/|Wear positive pressure self-contained breathing apparatus. ... Wear appropriate chemical protective clothing. /Parathion and compressed gas mixture; parathion dry mixture; parathion liquid mixture/

Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Solid streams of water may be ineffective. /Parathion/|Self contained breathing apparatus with a full facepiece operated in pressure demand, or other positive pressure mode /should be used in firefighting/. /Parathion/|If material /is/ on fire or /is/ involved in fire, extinguish fire using agent suitable for type of surrounding fire. ... Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Use foam, dry chemical, or carbon dioxide. /Parathion and compressed gas mixture/|If material /is/ on fire or involved in fire, extinguish fire using agent suitable for type of surrounding fire. ... Use water in flooding quantities as fog. Use "alcohol" foam, dry chemical or carbon dioxide. /Parathion mixture, dry/|If material /is/ on fire or involved in fire, do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. Solid streams of water may be ineffective. Use "alcohol" foam, dry chemical or carbon dioxide. /Parathion mixture, liquid/

1. VENTILATE AREA OF SPILL OR LEAK. 2. COLLECT FOR RECLAMATION, OR ABSORB IN VERMICULITE, DRY SAND, EARTH, OR A SIMILAR MATERIAL. /PARATHION/|If material is not on fire & is not involved in fire ... build dikes to contain flow as necessary. Attempt to stop leak if ... /it can be done/ without hazard. ... If material leaking (not on fire) consider evacuation from downwind area based on amount of material spilled, location & weather conditions. /Parathion/|Land spill: Dig a pit, pond, lagoon, or holding area to contain liquid, or solidmaterial. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash or cement powder. /Parathion/|Air spill: Apply water spray to knock down vapors. /Parathion/|For more Cleanup Methods (Complete) data for LEPTOPHOS (11 total), please visit the HSDB record page.

Releases of CERCLA hazardous substances are subject to the release reporting requirement of CERCLA section 103, codified at 40 CFR part 302, in addition to the requirements of 40 CFR part 355. Leptophos is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 500/10,000 lbs.

Soils were collected in 1976 from 28 farms located in six widely separated areas of southwestern Ontario(1); leptophos was detected (detection limit of 0.02 ppm) in 6 soils at concns ranging from 0.03 to 0.30 ppm(1).

Toxicity

most toxic

LD50 Rat male oral 52.8 mg/kg|LD50 Rat male dermal > 10,000 mg/kg|LD50 Rabbit oral 124 mg/kg|LD50 Rabbit skin 800 mg/kg

When used as an insecticide, leptophos is released directly to the environment through applications in sprays, dusts and other routes of application(1-2,SRC). Its' registration has been withdrawn in the US(3).

LEPTOPHOS HAD SHORT-LIVED EFFECTS ON PROCESSES & NUMBERS OF SOIL MICROORGANISMS.|TERRESTRIAL FATE: Laboratory studies have shown that leptophos is adsorbed strongly by soil and will not leach(1); log Koc values of 3.97-5.07 have been experimentally determined(1-2). Aqueous hydrolysis studies have shown that leptophos degrades more rapidly with increases in pH(3); aqueous hydrolysis half-lives of 35, 5.5 and 2.3 weeks have been measured at respective pHs of 6, 7 and 8 at 25 °C(3); therefore, hydrolysis may be an important transformation process in moist, alkaline soils(SRC). Insufficient data are available to assess the relative importance of biodegradation in soil. A foliar half-life of 4.0 days has been reported for endive plants(4). In field studies conducted in Israel, foliar residue levels of leptophos (as applied to tomato and grape plants) had dropped by 40-75%, from initial levels, after three weeks(5); the phenol derivative was a major degradation product(5). Based upon the results a laboratory study and a review of other leptophos persistence studies, it was concluded that leptophos is one of the most persistent organophosphorus compounds in the environment(6).|AQUATIC FATE: The results of various screening studies indicate that chemical degradation of leptophos may be more important in water than biodegradation(1-3). Hydrolysis studies have shown that degradation rates increase with increasing pH(3); at 25 °C, aqueous hydrolysis half-lives of 35, 5.5 and 2.3 weeks have been measured at respective pHs of 6, 7 and 8(3). Direct photolysis tests of methanol solutions of leptophos exposed to sunlight (half-life of about 50 days)(4) have shown that direct photolysis may contribute to transformation in water(SRC). In water, leptophos will partition from the water column to sediment and suspended material(1) and can be expected to remain largely in the sediment. Laboratory studies with various Egyptian natural waters have suggested the degradation rate may decrease in the presence of solids and sediment(5). A measured BCF of 6058 in topmouth gudgeon fish(6) indicates that bioconcentration in aquatic organisms may be an important environmental process(SRC).|ATMOSPHERIC FATE: Based upon a measured vapor pressure of 2.3X10-8 mm Hg at 20 °C(1), leptophos can exist in both the vapor and particulate phases in the ambient atmosphere, although the particulate phase may dominate(2,SRC). It will degrade rapidly in the vapor phase by reaction with photochemically produced hydroxyl radicals with an estimated half-life of about 5 hr(3,SRC). Particulate phase leptophos and aerosols released to air during spray applications of leptophos insecticide can be removed from air physically by dry and wet deposition(SRC).

MAJOR TRANSFORMATION PRODUCT WAS SMALL PERCENTAGE OF THE OXON ON LEAF SURFACES.|Leptophos was stable in the acid pH. At neutral pH, ca. 30% of the leptophos was degraded in 4 days. At alkaline pH, leptophos was unstable and followed first-order kinetics.|When exposed to sunlight, leptophos yielded desbromo leptophos.|The rate constant for the vapor phase reaction of leptophos with photochemically produced hydroxyl radicals has been estimated to be 6.01X10-11 cu cm/molecule-sec at 25 °C which corresponds to an atmospheric half-life of about 6.4 hours at an atmospheric concn of 5X10+5 hydroxyl radicals per cu cm(1,SRC). The aqueous hydrolysis half-life of leptophos in sterile water-ethanol (99:1) phosphate buffers at 25 °C was determined to be 350, 170, 35, 5.5 and 2.3 weeks at respective pHs of 4.5, 5.0, 6.0, 7.0 and 8.0(2). The photodegradation half-life of thin films of leptophos exposed to sunlight was experimentally determined to be approximately 20 days(3); the photodegradation half-life methanol solutions of leptophos exposed to sunlight was experimentally determined to be approximately 50 days(3); the two major photodegradation products were found to be leptophos phenol and leptophos oxon(3).

6.03e+03|Residues of leptophos and its metabolites exhibited bioaccumulation factors of 1443 and 48398 in fish and snail, respectively.|Using a continuous-flow system and a 14-day exposure period a leptophos BCF of 6058 was measured in topmouth gudgeon (Pseudorasbora parva) fish(1-2). This BCF suggests that bioconcentration in aquatic organisms has environmental importance(SRC). A BCF of 773 was estimated from equilibrium concentrations in a bioaccumulation study with bluegill fish(3).

3.16e+04 L/kg|The adsorption behavior of leptophos in soil and aqueous suspension of soil and sediment was studied in the laboratory(1); based upon results of leaching tests, leptophos was assigned a mobility factor of zero, which indicated that it was not leachable from either sand or various organic soils(1); Freundlich adsorption isotherms measured in a river sediment, sandy loam soil and sand(1) can be used to determine respective log Koc values of 5.07, 4.98 and 4.85(1). An experimentally determined log Koc of 3.97 has also been reported(2). According to a suggested classification scheme(3), these estimated Koc values indicate that leptophos is immobile in soil(SRC).

Based upon a measured vapor pressure of 2.3E-8 mm Hg(1) and a water solubility of 0.0047 mg/L at 20 °C(1), the Henry's Law constant for leptophos can be estimated to be 2.65X10-6 atm-cu m/mole(SRC). This value of Henry's Law constant indicates slow volatilization from water(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep flowing 1 m/sec with a wind velocity of 3 m/sec) can be estimated to be about 28 days(2,SRC). The volatilization half-life from a model environmental pond can be estimated to be about 307 days if the effect of adsorption to sediment is ignored(3,SRC); if the maximum effect of adsorption to sediment is included, the estimated volatilization half-life from the pond exceeds five years(3,SRC).

SURFACE WATER: Leptophos has been qualitatively detected in open waters of Lake St Clair of the Great Lakes ecosystem(1).

As part of the US Food and Drug Administration's Total Diet Study (Market Basket Survey of ready-to-eat foods) for fiscal year 1977, leptophos was detected in one of 300 food composites comprised of foods collected from 20 cities nationwide(1); the leptophos was detected in a fruit sample at concn of 0.012 ppm(1). As part of the US Food and Drug Administration's Total Diet Study (Market Basket Survey of ready-to-eat foods) for fiscal year 1976, leptophos was detected in two of 240 food composites comprised of foods collected from 20 cities nationwide(2); the leptophos was detected in garden fruit samples at concns of a trace (concn not available) and 0.009 ppm(2). For fiscal year 1975, leptophos was found in one of 240 food composites (garden fruit class) at a concn of 0.04 ppm(3). For fiscal year 1974, leptophos was found in five of 360 food composites (all in the garden fruit class) at concns of 0.013 to 0.09 ppm(4).

Occupational exposure to leptophos occurs through dermal contact and inhalation of dust and sprays, especially to workers applying the compound as an insecticide(1).

Drug Information

Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics. (See all compounds classified as Insecticides.)

AFTER 50 OR 250 MG/KG DOSE, PHOSVEL CONCN IN PLASMA REACHED MAX IN 3 HR, THEN DECLINED RAPIDLY; AFTER 72 HR NO RESIDUES WERE DETECTABLE. ELIMINATION FROM FAT WAS VERY SLOW.|IN SPITE OF SOME TENDENCY TO STORAGE, LEPTOPHOS, IN THE FORM OF WATER-SOLUBLE METABOLITES, IS EXCRETED RAPIDLY BY RODENTS, WITH VIRTUALLY COMPLETE ELIMINATION IN 48 TO 72 HR. IN MICE FED (14)C LEPTOPHOS AT A RATE OF 25 MG/KG THE RATE OF EXCRETION OF THE PHENOXY MOIETY WAS DISTINCTLY FASTER THAN THAT OF THE PHENYL MOIETY; RADIOACTIVITY WAS FOUND IN THE URINE AS LONG AS 6 DAYS AFTER TREATMENT.|IN RATS, EXCRETION OF RADIOACTIVE CARBON WAS ESSENTIALLY COMPLETE IN 72 HR FOLLOWING A SINGLE DOSE OR THE LAST OF A SERIES OF DOSES OF (14)C LEPTOPHOS. SIX DAYS AFTER THE LAST DOSE, THE HIGHEST CONCN OF (14)C WAS IN THE LIVER, BUT IT CONSTITUTED LESS THAN 0.25% OF THE TOTAL DOSE. MORE THAN 97% OF THE RADIOACTIVITY IN THE URINE OF RATS THAT HAD RECEIVED (14)C LEPTOPHOS WAS ORGANOSOLUBLE.|... FOLLOWING A SINGLE DOSE OF (14)C PHENYL LEPTOPHOS APPLIED TO THE COMBS OF HENS AT A SUBNEUROTOXIC RATE OF 50 MG/KG ... A TOTAL OF 35.4% OF THE APPLIED DOSE WAS ABSORBED DURING A 20-DAY EXPERIMENT. RADIOACTIVITY REACHED A PEAK OF 17.1% OF THE DOSE IN 12 HR AFTER APPLICATION; 5% OF THE DOSE STILL REMAINED AFTER 20 DAYS. THE HIGHEST (14)C CONCN AFTER 20 DAYS WERE IN MUSCLE, BRAIN, SPINAL CORD, CONTENTS OF THE LARGE INTESTINE, & BILE, IN THAT ORDER. COMBINED URINARY-FECAL EXCRETION ACCOUNTED FOR 24.3% OF THE APPLIED DOSE; EXPIRED CARBON DIOXIDE ACCOUNTED FOR 1.3% & EGG ACCOUNTED FOR 4.5%.

... 42 DAYS AFTER APPLICATION OF 2,240 G AI/HA TO CYNODON DACTYLON (BERMUDA GRASS) ... /ITS/ METABOLITE 4-BROMO-2,5-DICHLOROPHENOL 1.30 PPM, /WAS/ ... RECOVERED.|THE BIOTRANSFORMATION IN MICE OF LEPTOPHOS IS RAPID (ONLY SMALL AMOUNTS OF THE PARENT COMPOUND ARE FOUND IN FECES & IN URINE) & PREDICTABLE METABOLITES ARE IDENTIFIED ... 4-BROMO-2,5-DICHLOROPHENOL, MOSTLY CONJUGATED, ACCOUNTED FOR 96% OF A 25 MG/KG DOSE OF [PHENOXY-(14)C]LEPTOPHOS, & TENTATIVE IDENTIFICATION OF THE OXON OF O-DEMETHYL-LEPTOPHOS (1.1%) WAS MADE. COMPLEMENTARY STUDIES WITH [PHENYL-(14)C]LEPTOPHOS REVEALED THAT THE OXON OF O-DEMETHYL-LEPTOPHOS WAS AGAIN ONLY A MINOR URINARY METABOLITE, & THAT METHYL PHENYLPHOSPHONOTHIOIC ACID (56.6%), METHYL PHENYLPHOSPHONIC ACID (17.9%), & PHENYLPHOSPHONIC ACID (15.5%) ACCOUNTED FOR 90% OF THE URINARY LABEL. THE EXTENT OF THE IMPORTANCE OF O-DEMETHYLATION PATHWAYS IN THE BIOTRANSFORMATION OF LEPTOPHOS IS REVEALED BY THE EXCRETION (15.5%) OF PHENYLPHOSPHONIC ACID. THE ABSENCE OF O-DEMETHYL-LEPTOPHOS & PHENYLPHOSPHONOTHIOIC ACID FROM THE URINE MEANS THAT GLUTATHIONE-MEDIATED O-DEMETHYLATION OF LEPTOPHOS IS RELATIVELY UNIMPORTANT, COMPARED WITH THE PRODUCTION OF 4-BROMO-2,5-DICHLOROPHENOL.|LEPTOPHOS OXON WAS MODERATELY HYDROLYZED BY SUSCEPTIBLE SPECIES (LIVER MICROSOMAL FRACTIONS FROM CATS & HENS) & GREATLY HYDROLYZED BY NONSUSCEPTIBLE SPECIES (LIVER MICROSOMAL FRACTIONS FROM RATS & HAMSTERS). RATE OF DETOXIFICATION OF LEPTOPHOS IS INVERSELY CORRELATED WITH IN VIVO SUSCEPTIBILITY OF TESTED SPECIES TO DELAYED NEUROTOXICITY.|WHEN LEPTOPHOS WAS DOSED ENDOTRACHEALLY TO THE RAT, IT WAS METABOLIZED AT A RATE SIMILIAR TO THAT OF AN ORAL DOSE. THE METABOLITES IN THE RAT ARE THE SAME AS THOSE IN THE MOUSE, ALTHOUGH THE PROPORTION OF THE SINGLE METABOLITE THAT HAD RETAINED THE P=S LINKAGE WAS MUCH LESS. THIS IS NOT EXPECTED, AS THE RAT USUALLY MORE EXTENSIVELY OXIDIZES THE P=S GROUP THAN DOES THE MOUSE. RATS DOSED ON THREE CONSECUTIVE DAYS WITH 9.1 & 0.91 MG/KG LEPTOPHOS EXCRETED 30% & 73% RESPECTIVELY OF THE DOSE AS A MIXTURE OF THE THREE KNOWN PHOSPHORUS ACIDS, ACCOMPANIED BY THE SAME YIELD (12 + OR - 1%) OF 4-BROMO-2,5-DICHLOROPHENOL AT EACH DOSAGE.|For more Metabolism/Metabolites (Complete) data for LEPTOPHOS (13 total), please visit the HSDB record page.

18.20 Days|THE HALF-LIFE FOR ELIMINATION WAS 17 DAYS.

... DESBROMOLEPTOPHOS HAS BEEN REPORTED AS A MINOR IMPURITY IN TECHNICAL LEPTOPHOS & AS A PRODUCT OF THE CMPD IN THE PRESENCE OF UV LIGHT, EITHER IN THE LABORATORY OR IN PLANTS UNDER FIELD CONDITIONS.

This material is highly toxic; it is capable of causing death or permanent injury by exposure during normal use. (EPA, 1998)

Warning: Effects may be delayed up to 12 hours. Caution is advised. Note: Leptophos is a cholinesterase inhibitor. Signs and Symptoms of Leptophos Exposure: Acute exposure to leptophos may produce the following signs and symptoms: sweating, pinpoint pupils, blurred vision, headache, dizziness, profound weakness, muscle spasms, seizures, and coma. Mental confusion and psychosis may occur. Excessive salivation, nausea, vomiting, anorexia, diarrhea, and abdominal pain may also occur. The heart rate may decrease following oral exposure or increase following dermal exposure. Chest pain may be noted. Hypotension (low blood pressure) may be observed, although hypertension (high blood pressure) is not uncommon. Respiratory symptoms include dyspnea (shortness of breath), pulmonary edema, respiratory depression, and respiratory paralysis. Emergency Life-Support Procedures: Acute exposure to leptophos exposure may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination. Inhalation Exposure: 1. Move victims to fresh air. Emergency personnel should avoid self-exposure to leptophos. 2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer 100% humidified oxygen or other respiratory support. 3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures. 4. Transport to a health care facility. Dermal/Eye Exposure: 1. Remove victims from exposure. Emergency personnel should avoid self-exposure to leptophos. 2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer 100% humidified oxygen or other respiratory support. 3. Remove contaminated clothing as soon as possible. 4. If eye exposure has occurred, eyes must be flushed with lukewarm water for at least 15 minutes. 5. Wash exposed skin areas three times with soap and water. 6. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures. 7. Transport to a health care facility. Ingestion Exposure: 1. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer 100% humidified oxygen or other respiratory support. 2. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures. 3. Vomiting may be induced with syrup of Ipecac. If elapsed time since ingestion of leptophos is unknown or suspected to be greater than 30 minutes, do not induce vomiting and proceed to Step 4. Ipecac should not be administered to children under 6 months of age.Warning: Ingestion of leptophos may result in sudden onset of seizures or loss of consciousness. Syrup of Ipecac should be administered only if victims are alert, have an active gag-reflex, and show no signs of impending seizure or coma. If ANY uncertainty exists, proceed to Step 4.The following dosages of Ipecac are recommended: children up to 1 year old, 10 mL (1/3 oz); children 1 to 12 years old, 15 mL (1/2 oz); adults, 30 mL (1 oz). Ambulate (walk) the victims and give large quantities of water. If vomiting has not occurred after 15 minutes, Ipecac may be readministered. Continue to ambulate and give water to the victims. If vomiting has not occurred within 15 minutes after second administration of Ipecac, administer activated charcoal. 4. Activated charcoal may be administered if victims are conscious and alert. Use 15 to 30 g (1/2 to 1 oz) for children, 50 to 100 g (1-3/4 to 3-1/2 oz) for adults, with 125 to 250 mL (1/2 to 1 cup) of water. 5. Promote excretion by administering a saline cathartic or sorbitol to conscious and alert victims. Children require 15 to 30 g (1/2 to 1 oz) of cathartic; 50 to 100 g (1-3/4 to 3- 1/2 oz) is recommended for adults. 6. Transport to a health care facility. (EPA, 1998)

1. INSURE THAT A CLEAR AIRWAY EXISTS BY ASPIRATION OF SECRETIONS IF NECESSARY. ADMIN OXYGEN BY MECHANICALLY ASSISTED PULMONARY VENTILATION IF RESPIRATION IS DEPRESSED. IMPROVE TISSUE OXYGENATION AS MUCH AS POSSIBLE BEFORE ADMIN ATROPINE TO MINIMIZE RISK OF VENTRICULAR FIBRILLATION. IN SEVERE POISONINGS, IT MAY BE NECESSARY TO SUPPORT PULMONARY VENTILATION MECHANICALLY FOR SEVERAL DAYS. 2. ADMIN ATROPINE SULFATE IV, OR IM IF IV INJECTION IS NOT POSSIBLE. ... IN MODERATELY SEVERE POISONING: ADULT DOSAGE AND CHILDREN OVER 12 YR: 0.4-2.0 MG REPEATED EVERY 15 MIN UNTIL ATROPINIZATION IS ACHIEVED. MAINTAIN ATROPINIZATION WITH REPEATED DOSAGE OF 0.02-0.05 MG/KG BODY WEIGHT. /ORGANOPHOSPHATE PESTICIDES/|2. SEVERELY POISONED INDIVIDUALS MAY EXHIBIT REMARKABLE TOLERANCE TO ATROPINE; TWO OR MORE TIMES THE DOSAGES SUGGESTED ABOVE MAY BE NEEDED. THE DOSE OF ATROPINE MAY BE INCREASED AND THE DOSING INTERVAL DECREASED AS NEEDED TO CONTROL SYMPTOMS. CONTINUOUS IV INFUSION OF ATROPINE MAY BE NECESSARY WHEN ATROPINE REQUIREMENTS ARE MASSIVE. REVERSAL OF MUSCARINIC SYMPTOMS AND SIGNS, NOT AN ARBITRARY DOSE LIMIT, IS THE DESIRED END-POINT. PRESERVATIVE-FREE ATROPINE PRODUCTS SHOULD BE USED WHENEVER POSSIBLE. NOTE: PERSONS NOT POISONED OR ONLY SLIGHTLY POISONED BY ORGANOPHOSPHATES MAY DEVELOP SIGNS OF ATROPINE TOXICITY FROM SUCH LARGE DOSES. FEVER, MUSCLE FIBRILLATIONS, AND DELIRIUM ARE THE MAIN SIGNS OF ATROPINE TOXICITY. IF THESE APPEAR WHILE THE PATIENT IS FULLY ATROPINIZED, ATROPINE ADMINISTRATION SHOULD BE DISCONTINUED, AT LEAST TEMPORARILY, WHILE THE SEVERITY OF POISONING IS REEVALUATED. /ORGANOPHOSPHATE PESTICIDES/|3. DRAW BLOOD SAMPLE (HEPARINIZED) FOR CHOLINESTERASE ANALYSIS BEFORE ADMINISTRATION OF PRALIDOXIME, WHICH TENDS TO REVERSE THE CHOLINESTERASE DEPRESSION. 4. ADMIN PRALIDOXIME (PROTOPAM, 2-PAM) IN CASES OF SEVERE POISONING...IN WHICH RESP DEPRESSION, MUSCLE WEAKNESS & TWITCHINGS ARE SEVERE. ... ADULT DOSAGE AND CHILDREN OVER 12): GIVE 1.0-2.0 G IV @ NO MORE THAN 0.2 G/MIN. CHILD'S DOSE (UNDER 12 YR): GIVE 20-50 MG/KG (DEPENDING ON SEVERITY) IV, INJECTING NO MORE THAN HALF TOTAL DOSE/MIN. DOSAGE...MAY BE REPEATED IN 1-2 HR, THEN @ 10-12 HR INTERVAL IF NEEDED. IN VERY SEVERE POISONINGS, DOSAGE ... MAY BE DOUBLED. /ORGANOPHOSPHATE PESTICIDES/|4. BE PREPD TO ASSIST PULMONARY VENTILATION MECHANICALLY IF RESP ... DEPRESSED ... . 5. IN PATIENTS WHO HAVE BEEN POISONED BY ORGANOPHOSPHATE CONTAMINATION OF SKIN, CLOTHING, HAIR, AND/OR EYES, DECONTAMINATION MUST PROCEED CONCURRENTLY WITH WHATEVER RESUSCITATIVE AND ANTIDOTAL MEASURES ARE NECESSARY TO PRESERVE LIFE. ... 6. IF ... INGESTED IN QUANTITY PROBABLY SUFFICIENT TO CAUSE POISONING, THE STOMACH AND INTESTINE MUST BE EMPTIED. A. EMPTY THE STOMACH BY INTUBATION, ASPIRATION, AND LAVAGE, USING SLURRY OF ACTIVATED CHARCOAL IN ISOTONIC SALINE. RIGOROUS PRECAUTIONS MUST BE TAKEN TO PROTECT THE AIRWAY FROM ASPIRATION OF REGURGITATED. IF VICTIM IS UNCONSCIOUS OR OBTUNDED, INSERT A CUFFED ENDOTRACHEAL TUBE PRIOR TO GASTRIC INTUBATION. KEEP VICTIM'S HEAD BELOW LEVEL OF STOMACH DURING GASTRIC INTUBATION AND LAVAGE ... . KEEP VICTIM'S HEAD TURNED TO THE LEFT. /ORGANOPHOSPHATE PESTICIDES/|For more Antidote and Emergency Treatment (Complete) data for LEPTOPHOS (8 total), please visit the HSDB record page.

LEPTOPHOS HAS BEEN IMPLICATED IN POISONING & PARALYSIS OF SOME WORKERS IN TEXAS FACTORY WHERE IT WAS MANUFACTURED.|LEPTOPHOS PRODUCES TOXIC DISTAL AXONOPATHY INVOLVING AXONAL DEGENERATION IN CENTRAL & PERIPHERAL NERVOUS SYSTEM.|... IN ONE STUDY OF EGYPTIAN FARMERS EXPOSED TO LEPTOPHOS BY BOTH RESPIRATORY & DERMAL ROUTES IN CONNECTION WITH APPLICATION OF THE INSECTICIDE TO COTTON, NO MENTION WAS MADE OF POLYNEUROPATHY. CHARACTERISTIC ILLNESS PROPORTIONAL TO INHIBITION OF RED CELL CHOLINESTERASE ACTIVITY WAS OBSERVED.|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 TOSYMPATHO-ADRENAL DISCHARGE. 5. BRADYCARDIA OR TACHYCARDIA. VARYING DEGREES OF AV HEART BLOCK ... AS WELL AS ARIAL 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/

Leptophos

Leptophos Use and Manufacturing

Methods of Manufacturing

REACTION OF O-METHYL PHENYLTHIOPHOSPHONYL CHLORIDE WITH 4-BROMO-2,5-DICHLOROPHENOL.|PRODUCED BY THE REACTION OF PHENYLPHOSPHONOTHIOIC DICHLORIDE WITH METHANOL & TRIMETHYLAMINE IN TOLUENE AT ROOM TEMPERATURE, FOLLOWED BY REACTION WITH POTASSIUM 4-BROMO-2,5-DICHLOROPHENOXIDE IN BOILING TOLUENE ... .

Uses

Insecticide.

Production

(1972) PROBABLY GREATER THAN 4.54X10+5 G|(1975) PROBABLY GREATER THAN 4.54X10+5 G

NOT PERMITTED FOR USE IN THE USA; EXPERIMENTAL REGISTRATION & TEMPORARY TOLERANCE IN THE US WAS CANCELLED IN LATE 1975 DUE TO DELAYED NEUROTOXIC EFFECTS (1976)

... EMULSIFIABLE CONCN (360 G AI/L); WETTABLE POWDER (450 G/KG); DUST (30 G/KG); GRANULES (50 G/KG). /FORMER/|TECHNICAL MATERIAL, 87.2%; EMULSIFIABLE CONCN, 2.7%.

THE EMULSIFIABLE CONCN IS PARTICULARLY EFFECTIVE AGAINST LEPIDOPTERA, FOR EXAMPLE SPODOPTERA LITTORALIS ON COTTON AT 1.5 KG/HA; ON VEGETABLES & FRUIT AT 100 G/100 L. GRANULES AT 1.5 KG AI/HA ARE EFFECTIVE FOR THE CONTROL OF OSTRINIA NUBILALIS ON MAIZE. THERE IS EVIDENCE THAT IT HAS A POSITIVE TEMPERATURE COEFFICIENT AGAINST LEPIDOPTERA & MAY THEREFORE BE MORE USEFUL IN WARMER CLIMATES. /FORMER/

... BY IR SPECTROSCOPY @ 9.62 UM OR BY GAS LIQUID CHROMATOGRAPHY RESIDUES ARE DETERMINED BY GLC WITH FLAME-PHOTOMETRIC DETECTION OR THERMIONIC DETECTION.|RAPID TLC METHOD FOR ANALYSIS OF LEPTOPHOS & ITS POSSIBLE DEGRADATION PRODUCTS.|CONVENTIONAL ELECTRON IMPACT & METHANE CHEMICAL IONIZATION WERE USED TO OBTAIN POSITIVE ION MASS SPECTRA OF 16 TYPICAL ORGANOPHOSPHORUS PESTICIDES, INCLUDING LEPTOPHOS.|MULTIRESIDUE METHOD FOR ORGANOPHOSPHORUS PESTICIDES. RESIDUES ARE MEASURED BY GLC & IDENTIFIED BY COMBINATIONS OF GAS, THIN LAYER, OR PAPER CHROMATOGRAPHY.|For more Analytic Laboratory Methods (Complete) data for LEPTOPHOS (10 total), please visit the HSDB record page.

INSECTICIDES

Computed Properties

Molecular Weight:412.1
XLogP3:6.3
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:4
Exact Mass:409.86996
Monoisotopic Mass:409.86996
Topological Polar Surface Area:50.6
Heavy Atom Count:20
Complexity:368
Undefined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes

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