Diisopropyl Fluorophosphate

H300 (100%): Fatal if swallowed [Danger Acute toxicity, oral]

H310 (100%): Fatal in contact with skin [Danger Acute toxicity, dermal]

H330 (100%): Fatal if inhaled [Danger Acute toxicity, inhalation]

P260, P262, P264, P270, P271, P280, P284, P301+P316, P302+P352, P304+P340, P316, P320, P321, P330, P361+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 40 reports by companies from 3 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

Warning: Effects may be delayed up to 12 hours. Caution is advised.

Note: Isofluorphate is a cholinesterase inhibitor.

Signs and Symptoms of Acute Isofluorphate Exposure: Acute exposure to isofluorphate 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 isofluorphate 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 isofluorphate.

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. Rush to a health care facility.

Dermal/Eye Exposure:

1. Remove victims from exposure. Emergency personnel should avoid self-exposure to isofluorphate.

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. Rush 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 isofluorphate 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 isofluorphate 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. Rush to a health care facility. (EPA, 1998)

Stay upwind; keep out of low areas. Wear positive pressure breathing apparatus and special protective clothing.

(Non-Specific -- Organophosphorous Pesticide, n.o.s.) Dry chemical, carbon dioxide, water spray, or foam. For large fires, water spray, fog, or foam. Fight fire from maximum distance. Dike fire control water for later disposal. (EPA, 1998)

Fire Fighting: Self-contained breathing apparatus with a full facepiece operated in pressure-demand or other positive pressure mode. /Parathion/

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

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 the immediate precautionary measure distance, in the downwind direction, as necessary.

FIRE: If tank, rail tank car or highway tank 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, 2024)

Decontamination may be achieved by using soap washings followed by alcohol-soap washings with tincture of green soap.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number P043, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

Potential for fluidized bed incineration with a temperature of 840-1800 °C with residence times for liquids and gases: seconds; solids: longer.

Potential candidate for rotary kiln incineration with a temperature of 1,500-2,900 °C with residence times for liquids and gases: seconds; solids: hours. /Data from table/

Potential candidate for liquid injection with a temperature of 1,200-2,900 °C with a residence time of 0.1-2 seconds. /Data from table/

Clothing which has had any possibility of being contaminated ... should be placed into closed containers for storage until it can be discarded or provisions are made for ... removal from the clothing. /Parathion/

Provide an emergency eyewash station. /Parathion/

Non-impervious clothing which becomes contaminated ... should be removed immediately and not reworn until ... /provisions are made for/ removal /from/ the clothing. /Parathion/

Skin that becomes contaminated ... should be immediately washed ... with soap or mild detergent and water. /Parathion/

For more Preventive Measures (Complete) data for DIISOPROPYL FLUOROPHOSPHATE (7 total), please visit the HSDB record page.

When handling in open containers, protect the eyes, nose, and mouth with a suitable mask, and avoid contact with skin. (Non-Specific -- Organophosphorus Pesticide, n.o.s.) Stay upwind; keep out of low areas. Ventilate closed spaces before entering them. Remove and isolate contaminated clothing at the site. Do not touch spilled material. Use water spray to reduce vapors. Take up small spills with sand or other noncombustible absorbent material and place in containers for later disposal. Dike far ahead of large spills for later disposal. (EPA, 1998)

... MUST BE STORED IN ITS SEALED ORIGINAL CONTAINERS, IN WELL-AIRED, FRESH & DRY STOREHOUSES OR IN SHADED & POSSIBLY WELL-AIRED PLACES. IT IS RECOMMENDED THAT THE PRODUCT'S TEMP ... NOT EXCEED 25-30 °C, & KEEP ... AWAY FROM SOURCES OF HEAT, FREE FLAMES OR SPARK-GENERATING EQUIPMENT. CONTAINERS MUST BE STACKED IN SUCH A WAY AS TO PERMIT FREE CIRCULATION OF AIR ... AT BOTTOM & INSIDE OF PILES. STORAGE AREAS MUST BE LOCATED AT SUITABLE DISTANCE FROM INHABITED BUILDINGS, ANIMAL SHELTERS, & FOOD STORES; MOREOVER, THEY MUST BE INACCESSIBLE TO UNAUTHORIZED PERSONS, CHILDREN, & DOMESTIC ANIMALS. /DIMETHOATE/

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]

0.0096 [mg/m3]

0.11 [mg/m3]

1.7 [mg/m3]

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)

... WHEN HANDLING ISOFLUROPHATE IN OPEN CONTAINERS, PROTECT THE EYES, NOSE, & MOUTH WITH A SUITABLE MASK, & AVOID CONTACT WITH SKIN.

Data suggest break-through times of approximately an hour or more for protective clothing made of butyl or nitrile rubber. /Organo-phosphorous compounds/

Respiratory protection is as follows: particulate or vapor concentration: 1 mg/cu m or less: Any chemical cartridge respirator with an organic vapor cartridge and dust, fume, and mist filter, including pesticide respirators which meet the requirements of this class, or any supplied-air respirator, or any self-contained breathing apparatus. 5 mg/cu m or less: A chemical cartridge respirator with a full facepiece, organic vapor cartridge, and dust, fume, and mist filter, including pesticide respirators which meet the requirements of this class, or a gas mask with a chin-style or a front- or back-mounted organic vapor canister and dust, fume, and mist filter, including pesticide respirators which meet the requirements of this class, or any supplied-air respirator with a full facepiece, helmet, or hood, or any self-contained breathing apparatus with a full facepiece. 20 mg/cu m or less: A powered air-purifying respirator with an organic vapor cartridge and high efficiency particulate filter, including pesticide respirators which meet the requirements of this class or a type C supplied-air respirator operated in pressure-demand or other positive pressure or continuous-flow mode. Greater than 20 mg/cu m or entry and escape from unknown concentrations: Self-contained breathing apparatus with a full facepiece operated in pressure-demand or other positive pressure mode, or a combination respirator which includes a type C supplied-air respirator with a full facepiece operated in pressure-demand or other positive pressure or continuous-flow mode and an auxiliary self-contained breathing apparatus operated in pressure-demand or other positive pressure mode. Escape: Any gas mask providing protection against organic vapors and particulates or any escape self-contained breathing apparatus. /Parathion/

Isofluorphate appears as oily liquid. Clear, colorless or faintly yellow liquid. This material is used as a research tool in neuroscience for its ability to inhibit cholinesterase (by phosphorylation) on an acute/sub-acute basis and to produce a delayed neuropathy. An insecticide. Used in Germany as a basis for "nerve gases". (EPA, 1998)

Clear colorless or slightly yellow liquid; [HSDB] Clear colorless liquid; [MSDSonline]

CLEAR, COLORLESS OR FAINTLY YELLOW LIQUID

Oily liquid

Very weak fruity odor

144 °F at 9 mmHg (EPA, 1998)

62 °C @ 9 mm Hg; 46 °C @ 5 mm Hg; 183 °C @ 760 mm Hg (by extrapolation)

185 °C @760 [mm Hg]

-116 °F (EPA, 1998)

Solubility in water @ 25 °C: 1.54% wt/wt; sol in vegetable oils; not very sol in mineral oils

Sol in ether

SOL IN ALCOHOL

Soluble in organic solvents, fuel and lubricants.

6.78e+00 g/L

1.055 (EPA, 1998) - Denser than water; will sink

1.07 @25 °C

6.4 (Air= 1)

0.579 mmHg at 68 °F (EPA, 1998)

0.57 [mmHg]

0.579 mm Hg @ 20 °C

0.58 [mm Hg] @25 °C

ANHYDROUS CMPD OR OIL SOLUTIONS ARE STABLE IN GLASS CONTAINERS AT ROOM TEMPERATURES.

When heated to decomposition it emits toxic fumes of /Fluoride and Phosporous Oxide/

Forms hydrogen fluoride in presence of moisture; decomp in water @ pH about 2.5

DFP yields phosphate as a result of decomposition with sulfuric acid.

Index of refraction: 1.3830 @ 25 °C/D

Oil/water partition coefficient: log= 0.93

Carbon tetrachloride/water partition coefficient: 1.57-1.58

The anhydride compd or oil solns are stable in glass containers at room temp.

31P nuclear magnetic resonance spectrum

Boiling point

Chemical shift

Heat of sublimation

Spin-spin coupling constant

Surface tension

Vapor pressure

Viscosity

Pharmaceuticals -> Sensory organs -> Ophthalmologicals

Pharmaceuticals -> Listed in ZINC15

FDA approved drugs -> Active ingredient

Forms hydrogen fluoride in presence of moisture; decomposes in water at pH about 2.5.

Sulfonates, Phosphonates, and Thiophosphonates, Organic

Acyl Halides, Sulfonyl Halides, and Chloroformates

Water-Reactive

Organophosphates, such as ISOFLUORPHATE, 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. Isofluorphate also reacts with water to generate hydrofluoric acid, which can cause severe chemical burns and is one of the few materials that can etch glass. Fluoride is quite reactive, acting as a weak base and participating in some unique reactions. In particular, fluorides react strongly with compounds containing calcium, magnesium, or silicon ions, which means that solutions containing soluble fluorides are corrosive to both living tissue and glass.

Other Poison - Organophosphate

LC50 (rat) = 360 mg/m3/10min

LD50 Rat oral 5 mg/kg

IN SOME CASES ANOTHER PARASYMPATHOMIMETIC AGENT SUCH AS CARBACHOL ... MAY ENHANCE THE EFFECT OF ISOFLUROPHATE. HOWEVER, ACTION OF ISOFLUROPHATE IS INHIBITED BY PRIOR INSTILLATION OF PHYSOSTIGMINE.

Phenyl methyl sulfonyl fluoride (PMSF) was able to protect hens from delayed neurotoxicity when given 4 hr before 1.7 mg/kg sc DFP. However, PMSF was ineffective at preventing paralysis when given later than 4 hr before DFP admin. These results support the notion that PMSF acts at the same site as the organophosphorus esters.

Using the hot-plate test in mice di-isopropylfluorophosphate potentiates the antinociceptive activity of alfentanil but has no effect on the activity of morphine or fentanyl.

Skin penetration of the alkyl phophates, diisopropyl fluorophosphate (DFP) and N,N-dimethylamino-o-ethylcyanophosphate (Tabun), was investigated, in vitro and in vivo, in guinea pigs and rats. As a basis for the development of skin barrier creams (formulations), a series of polyethylene glycols was chosen. For some formulations a short-time inhibition of Tabun-penetration in vitro was found, which could not be verified in vivo. In vivo all formulations gave an enhancement of penetration. Mixed with Tabum (10:1) polyethylene glycol 400 strongly diminished the penetration of the former substance.

For more Interactions (Complete) data for DIISOPROPYL FLUOROPHOSPHATE (7 total), please visit the HSDB record page.

... Since thermoregulatory disturbance may itself contribute to the morbidity and mortality in individuals exposed to cholinesterase inhibitors, and since this may be independent of the effect of the toxin on cholinesterase activity, treatment should be instituted to correct hypothermia as well as to combat cholinergic stimulation directly.

... Hexamethonium, trimethaphan, and mecamylamine are ganglionic blockers which can reduce acetylcholine (ACh) release presynaptically. All these agents are capable of protecting mice from diisopropyl fluorophosphate (DFP) intoxication by prolonging the latent period of death or by completely preventing death. Combinations of these agents with 2-pyridine aldoxime methochloride (2-PAM) (50 mg/kg) improved prophylactic action even further even further. These results indicate that reduction of ACh release presynaptically plus neutralization of organophosphates with 2-PAM could be an effective way to reduce mortality in patients exposed to organophosphorus poisons.

... Mice were injected with several drugs which have in common the ability to block sodium-channels. Drugs tested were ketamine, phenobarbital, lidocaine, morphine, prednisolone, and lithium. All mice were injected with DFP (7.6 mg/kg) plus atropine; the treatment groups were simultaneously injected with the test drug, while controls received an equal volume of physiological saline. All the test drugs, at one or more doses, revealed protection, not only in terms of prolonging symptom onset but also in terms of mortality. The reduction in mortality was quantitatively similar for each drug. Although the various drugs could have protected by many different, coincidental mechanisms, a more parsimonious explanation is that the effect could have been due to one property which all had in common; namely, sodium-channel blockade.

Maintaining adequate respiratory function should be the first treatment measure taken. In cases of ingestion, activated charcoal is indicated. Atropine is the drug of first choice ...

... /Authors/ showed that the carbamate anticholinesterase physostigmine could protect cat cholinesterase against inactivation by DFP in vivo ... .

The assessment of exposure to the organophosphate pesticides, bromophos and dicrotophos, can be accomplished through measurement of these compounds in the blood. However, since organophosphate pesticides are rapidly cleared from the blood, it is difficult to be able to detect the pesticides in blood unless very large quantities have been absorbed. This test may be useful for identification of the compound in cases of severe exposure, although documented tests for measurement of specific organophosphate pesticides in blood are very limited. Blood Reference Ranges: Normal - None detected; Exposed - Not detected; Toxic - Not established. Serum or Plasma Reference Ranges: Normal - Not established; Exposed - Not established; Toxic - Not established. Urine: The assessment of organophosphate pesticide exposure can be accomplished through measurement of the following alkyl phosphate metabolites: dimethylphosphate, diethylphosphate, dimethylthiophosphate, diethylthiophosphate, dimethyldithiophosphate, and diethyldithiophosphate. ... The one limitation to measurement of urinary alkyl metabolites is that this test is only useful for assessing recent exposure, due to the short half-life of organophosphate pesticides. Urine Reference Ranges: Normal - Note established; Exposed - Not established; Toxic - Not established. /Organophosphate Pesticides/

Initial Medical Examination: A complete history and physical examination: The purpose is to detect pre-existing conditions that might place the exposed employee at increased risk, and to establish a baseline for future health monitoring. ... Examination of the respiratory system, nervous system, cardiovascular system, eyes, and attention to the cholinesterase levels in the blood should be stressed. The skin should be examined for evidence of chronic disorders. ... The cholinesterase activity in the serum and erythrocytes should be determined by using medically acceptable biochemical tests prior to any new period of exposure. /Parathion/

... A 12-month-old boy, who had received one drop of 0.1% DFP in each eye daily for 2 months, experienced two brief apneic spells, with probable seizure activity for 1 or 2 minutes each time ... miotic, unreactive pupils, profuse nasal discharge & possible motor weakness /noted/. Eight hr after admin, he had a typical grand mal convulsion lasting 2 to 3 minutes. ... The cholinesterase activity of serum collected 60 hr after the last eye drop was below the range of normal & 44% of the average normal.

TREATMENT OF GLAUCOMA WITH POTENT, LONG-ACTING ANTICHOLINESTERASE AGENTS (INCLUDING ... ISOFLUROPHATE) FOR 6 MONTHS OR LONGER CARRIES HIGH RISK OF THE DEVELOPMENT OF A SPECIFIC TYPE OF CATARACT, WHICH BEGINS AS ANTERIOR SUBCAPSULAR VACUOLES. ALTHOUGH FORMATION OF SPONTANEOUS CATARACTS IS QUITE COMMON WITHIN COMPARABLE AGE GROUPS, THE INCIDENCE OF LENTICULAR OPACITIES UNDER SUCH CIRCUMSTANCES CAN BE AS HIGH AS 50%; THE HAZARD IS APPARENTLY INCREASED IN PROPORTION TO THE STRENGTH OF SOLUTION, FREQUENCY OF INSTILLATION, DURATION OF THERAPY, & AGE OF THE PATIENT. THE UNDERLYING MECHANISM REMAINS ELUSIVE ... MISCELLANEOUS OCULAR SIDE EFFECTS THAT MAY OCCUR FOLLOWING LOCAL INSTILLATION OF ANTICHOLINESTERASE AGENTS ARE HEADACHE, BROW PAIN, BLURRED VISION, PHACODINESIS, PERICORNEAL INJECTION, CONGESTIVE IRITIS, VARIOUS ALLERGIC REACTIONS, &, RARELY, RETINAL DETACHMENT.

... DFP ... has the property of inducing a ... delayed neurotoxicity. ... The clinical picture is that of a severe polyneuritis that begins several days after exposure to a sufficient single or cumulative amt of the toxic cmpd. It is manifested initially by mild sensory disturbances, ataxia, weakness, and ready weakness of the legs, accompanied by reduced tendon reflexes & ... muscle twitching, fasciculation, & tenderness to palpation. In severe cases, the weakness may progress eventually to complete flaccid paralysis that, over the course of weeks or months, is often succeeded by a spastic paralysis with a concomitant exaggeration of reflexes. During these phases, the muscles show marked wasting. Recovery may require 2 or more yr.

Do not inhale vapors. Avoid contact with skin. Even traces of the vapor cause myosis. Highly toxic; cholinesterase inhibitor.

For more Human Toxicity Excerpts (Complete) data for DIISOPROPYL FLUOROPHOSPHATE (6 total), please visit the HSDB record page.

... IN ANIMALS POISONED WITH DFP, PLASMA CHOLINESTERASE ACTIVITY RETURNS TO NORMAL WITHIN SEVERAL DAYS TO A FEW WK, BECAUSE IT IS RELATIVELY RAPIDLY REPLACED BY NEW ENZYME SYNTHESIZED IN THE LIVER. THE ACETYLCHOLINESTERASE ACTIVITY OF ERYTHROCYTES, HOWEVER, REMAINS DEPRESSED FOR DURATION OF RED CELL'S LIFE.

IN SEVERE POISONING, MOTOR FIBERS ARE INVOLVED, & THERE IS PARALYSIS & EXTENSIVE DAMAGE TO RHOMBENCEPHALON & SPINAL CORD WITH DEGENERATION OF SPINOCEREBELLAR TRACTS, CEREBELLAR PONTINE NUCLEI, & VENTRAL LUMBAR, THORACIC, & CERVICAL TRACTS.

DIISOPROPYL FLUOROPHOSPHATE ADMIN IM TO WISTAR RATS, 0.5 MG/KG EVERY 72 HR FOR 730 DAYS, PRODUCED 16/100 PITUITARY TUMORS (CHROMOPHOBE ADENOMA). SPONTANEOUS INCIDENCE "RARE". /FROM TABLE/

THE ACUTE AND DELAYED BEHAVIORAL EFFECTS OF DFP WERE STUDIED IN WHITE-LEGHORN HENS TRAINED TO KEY-PECK UNDER A MULTIPLE FIXED-RATIO, FIXED-INTERVAL (MULT FR F1) SCHEDULE OF FOOD PRESENTATION. ACUTE EFFECTS CONSISTED OF DOSE-RELATED RESPONSE-RATE DECREASES WHICH WERE SIMILAR FOR BOTH FR AND FI SCHEDULE COMPONENTS. FOLLOWING A RETURN TO CONTROL RESPONDING FOR NO LESS THAN 7 DAYS, DELAYED EFFECTS OCCURRED. BEHAVIORAL EFFECTS PRECEDED NEUROTOXIC EFFECTS. THESE LATTER EFFECTS FIRST APPEARED AS ATAXIA AND PROGRESSED TO LEG PARALYSIS AND SOMETIMES DEATH. DELAYED EFFECTS FOLLOWED BOTH ACUTE (0.5-1.0 MG/KG) DOSES AS WELL AS DOSES (0.125-0.25 MG/KG) HAVING NO OR LITTLE ACUTE BEHAVIORAL EFFECTS.

For more Non-Human Toxicity Excerpts (Complete) data for DIISOPROPYL FLUOROPHOSPHATE (30 total), please visit the HSDB record page.

The inhibition of nonspecific esterase activity, and/or inhibition of aromatic amino acid esterase activity, and/or potential effects on specific cellular functions (phagocytosis, immunoglobulin G synthesis, and inflammatory and immune mediator release) were evaluated with organic chemicals added to human peripheral blood monocytes. Diisopropyl phosphorofluoridate at a concentration of 1.5 mM inhibited monocyte alpha-naphthyl acetate esterase activity by 65% (assay method not reported).

Persons with a history of reduced pulmonary function, convulsive disorders, or recent exposure to anticholinesterase agents would be expected to be at an increased risk. /Parathion/

Diisopropyl fluorophosphate's production and use as a cholinergic and miotic may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 0.54 mm Hg at 25 °C indicates diisopropyl fluorophosphate will exist solely in the vapor-phase in the ambient atmosphere. Vapor-phase diisopropyl fluorophosphate will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 5 hrs. If released to soil, diisopropyl fluorophosphate is expected to have very high mobility based upon an estimated Koc of 31. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 3.2X10-6 atm-cu m/mole. Diisopropyl fluorophosphate will not volatilize from dry soil surfaces based upon its vapor pressure. If released into water, diisopropyl fluorophosphate is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 250 hrs and 120 days, respectively. An estimated BCF of 1 suggests the potential for bioconcentration in aquatic organisms is low. Diisopropyl fluorophosphate does undergo hydrolysis to HF and diisopropyl phosphate; half-lives range from 16.7 hrs to 2.2 days at temperatures of 37 to 25 °C and 72 hrs to several days at temperatures of 15 to 30 °C. Occupational exposure to diisopropyl fluorophosphate may occur through dermal contact with this compound at workplaces where diisopropyl fluorophosphate is produced or used. (SRC)

Diisopropyl fluorophosphate's production and use as a cholinergic and miotic (in veterinary medicine)(1) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 31(SRC), determined from a structure estimation method(2), indicates that diisopropyl fluorophosphate is expected to have very high mobility in soil(SRC). Volatilization of diisopropyl fluorophosphate from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.2X10-6 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Diisopropyl fluorophosphate does undergo hydrolysis to HF and diisopropyl phosphate; half-lives range from 16.7 hrs-2.2 days at temperatures of 37-25 °C(5,6) and 72 hrs-several days at temperatures of 15-30 °C(7,8). Diisopropyl fluorophosphate is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 0.54 mm Hg(SRC), determined from a fragment constant method(4).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 31(SRC), determined from an estimation method(2), indicates that diisopropyl fluorophosphate is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 3.2X10-6 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 250 hr and 120 days, respectively(SRC). Diisopropyl fluorophosphate does undergo hydrolysis to HF and diisopropyl phosphate; half-lives range from 16.7 hrs-2.2 days at temperatures of 37-25 °C(8,9) and 72 hrs-several days at temperatures of 15-30 °C(10,11). According to a classification scheme(5), an estimated BCF of 1(SRC), from an estimated log Kow of 1.13(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low.

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), diisopropyl fluorophosphate, which has a vapor pressure of 0.54 mm Hg at 25 °C(2), is expected to exist solely in the vapor-phase in the ambient atmosphere. Vapor-phase diisopropyl fluorophosphate is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 5 hrs(SRC), calculated from its rate constant of 8.0X10-11 cu cm/molecule-sec at 25 °C(3) determined using a structure estimation method(3).

Microbial cell-free extracts were found to contain lysase enzymes capable of hydrolyzing diisopropyl fluorophosphate(1). This indicates that intact microorganisms in the environment may also be capable of biodegrading diisopropyl fluorophosphate. One study reported that Pseudomonas melophthora could degrade diisopropyl fluorophosphate in the presence of yeast extract, mannitol, and acetone(2). Diisopropyl fluorophosphate was found to be rapidly degraded (no quantitative rate was given) in ruminal fluid(3), which contains anaerobic microorganisms.

The rate constant for the vapor-phase reaction of diisopropyl fluorophosphate with photochemically-produced hydroxyl radicals has been estimated as 8.0X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Diisopropyl fluorophosphate does undergo hydrolysis. Diisopropyl fluorophosphate in a 0.03 m bicarbonate buffer with a pH of 7.4 at a temperature of 37 °C had a half-life of 16.7 hours(2). Extrapolation of these data to 25 °C(3) gives a half-life of approximately 2.2 days. Other researchers report a half-life of several days at 30 °C and pH 7.6 and that in dilute solutions (pH not indicated) hydrolysis goes to completion in 72 hr at 15 °C(4,5). A kinetic study of the hydrolysis of diisopropyl fluorophosphate in neutral and acid aqueous solutions found the reaction to be autocatalytic and catalyzed by hydrogen ions for an initial rate of 0.6%/hr that was independent of the initial concentration of diisopropyl fluorophosphate and produced diisopropyl phosphate and HF(5). Cupric ions are extremely effective at catalyzing the hydrolysis of diisopropyl fluorophosphate although other ions are less effective or without effect(4). This suggests that some soils may catalyze hydrolysis but experimental data are lacking.

An estimated BCF of 1 was calculated for diisopropyl fluorophosphate(SRC), using an estimated log Kow of 1.13(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low.

Using a structure estimation method based on molecular connectivity indices(1), the Koc for diisopropyl fluorophosphate can be estimated to be 31(SRC). According to a classification scheme(2), this estimated Koc value suggests that diisopropyl fluorophosphate is expected to have very high mobility in soil.

The Henry's Law constant for diisopropyl fluorophosphate is estimated as 3.2X10-6 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that diisopropyl fluorophosphate is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 250 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 120 days(SRC). Diisopropyl fluorophosphate's Henry's Law constant(1) indicates that volatilization from moist soil surfaces may occur(SRC). Diisopropyl fluorophosphate is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 0.54 mm Hg(SRC), determined from a fragment constant method(3).

Occupational exposure to diisopropyl fluorophosphate may occur through dermal contact with this compound at workplaces where diisopropyl fluorophosphate is produced or used. (SRC)

Diisopropyl fluorophosphate's production and use as a cholinergic and miotic may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 0.54 mm Hg at 25 °C indicates diisopropyl fluorophosphate will exist solely in the vapor-phase in the ambient atmosphere. Vapor-phase diisopropyl fluorophosphate will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 5 hrs. If released to soil, diisopropyl fluorophosphate is expected to have very high mobility based upon an estimated Koc of 31. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 3.2X10-6 atm-cu m/mole. Diisopropyl fluorophosphate will not volatilize from dry soil surfaces based upon its vapor pressure. If released into water, diisopropyl fluorophosphate is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 250 hrs and 120 days, respectively. An estimated BCF of 1 suggests the potential for bioconcentration in aquatic organisms is low. Diisopropyl fluorophosphate does undergo hydrolysis to HF and diisopropyl phosphate; half-lives range from 16.7 hrs to 2.2 days at temperatures of 37 to 25 °C and 72 hrs to several days at temperatures of 15 to 30 °C. Occupational exposure to diisopropyl fluorophosphate may occur through dermal contact with this compound at workplaces where diisopropyl fluorophosphate is produced or used. (SRC)

Diisopropyl fluorophosphate's production and use as a cholinergic and miotic (in veterinary medicine)(1) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 31(SRC), determined from a structure estimation method(2), indicates that diisopropyl fluorophosphate is expected to have very high mobility in soil(SRC). Volatilization of diisopropyl fluorophosphate from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.2X10-6 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Diisopropyl fluorophosphate does undergo hydrolysis to HF and diisopropyl phosphate; half-lives range from 16.7 hrs-2.2 days at temperatures of 37-25 °C(5,6) and 72 hrs-several days at temperatures of 15-30 °C(7,8). Diisopropyl fluorophosphate is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 0.54 mm Hg(SRC), determined from a fragment constant method(4).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 31(SRC), determined from an estimation method(2), indicates that diisopropyl fluorophosphate is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 3.2X10-6 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 250 hr and 120 days, respectively(SRC). Diisopropyl fluorophosphate does undergo hydrolysis to HF and diisopropyl phosphate; half-lives range from 16.7 hrs-2.2 days at temperatures of 37-25 °C(8,9) and 72 hrs-several days at temperatures of 15-30 °C(10,11). According to a classification scheme(5), an estimated BCF of 1(SRC), from an estimated log Kow of 1.13(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low.

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), diisopropyl fluorophosphate, which has a vapor pressure of 0.54 mm Hg at 25 °C(2), is expected to exist solely in the vapor-phase in the ambient atmosphere. Vapor-phase diisopropyl fluorophosphate is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 5 hrs(SRC), calculated from its rate constant of 8.0X10-11 cu cm/molecule-sec at 25 °C(3) determined using a structure estimation method(3).

Microbial cell-free extracts were found to contain lysase enzymes capable of hydrolyzing diisopropyl fluorophosphate(1). This indicates that intact microorganisms in the environment may also be capable of biodegrading diisopropyl fluorophosphate. One study reported that Pseudomonas melophthora could degrade diisopropyl fluorophosphate in the presence of yeast extract, mannitol, and acetone(2). Diisopropyl fluorophosphate was found to be rapidly degraded (no quantitative rate was given) in ruminal fluid(3), which contains anaerobic microorganisms.

The rate constant for the vapor-phase reaction of diisopropyl fluorophosphate with photochemically-produced hydroxyl radicals has been estimated as 8.0X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Diisopropyl fluorophosphate does undergo hydrolysis. Diisopropyl fluorophosphate in a 0.03 m bicarbonate buffer with a pH of 7.4 at a temperature of 37 °C had a half-life of 16.7 hours(2). Extrapolation of these data to 25 °C(3) gives a half-life of approximately 2.2 days. Other researchers report a half-life of several days at 30 °C and pH 7.6 and that in dilute solutions (pH not indicated) hydrolysis goes to completion in 72 hr at 15 °C(4,5). A kinetic study of the hydrolysis of diisopropyl fluorophosphate in neutral and acid aqueous solutions found the reaction to be autocatalytic and catalyzed by hydrogen ions for an initial rate of 0.6%/hr that was independent of the initial concentration of diisopropyl fluorophosphate and produced diisopropyl phosphate and HF(5). Cupric ions are extremely effective at catalyzing the hydrolysis of diisopropyl fluorophosphate although other ions are less effective or without effect(4). This suggests that some soils may catalyze hydrolysis but experimental data are lacking.

An estimated BCF of 1 was calculated for diisopropyl fluorophosphate(SRC), using an estimated log Kow of 1.13(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low.

Using a structure estimation method based on molecular connectivity indices(1), the Koc for diisopropyl fluorophosphate can be estimated to be 31(SRC). According to a classification scheme(2), this estimated Koc value suggests that diisopropyl fluorophosphate is expected to have very high mobility in soil.

The Henry's Law constant for diisopropyl fluorophosphate is estimated as 3.2X10-6 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that diisopropyl fluorophosphate is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 250 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 120 days(SRC). Diisopropyl fluorophosphate's Henry's Law constant(1) indicates that volatilization from moist soil surfaces may occur(SRC). Diisopropyl fluorophosphate is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 0.54 mm Hg(SRC), determined from a fragment constant method(3).

Occupational exposure to diisopropyl fluorophosphate may occur through dermal contact with this compound at workplaces where diisopropyl fluorophosphate is produced or used. (SRC)

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number P043, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

Potential for fluidized bed incineration with a temperature of 840-1800 °C with residence times for liquids and gases: seconds; solids: longer.

Potential candidate for rotary kiln incineration with a temperature of 1,500-2,900 °C with residence times for liquids and gases: seconds; solids: hours. /Data from table/

Potential candidate for liquid injection with a temperature of 1,200-2,900 °C with a residence time of 0.1-2 seconds. /Data from table/