Diisopropyl methylphosphonate

180.18

180.18

1761635

215-896-0

56V3OG5DC7

DTXSID5024051

2931900090

45.34000

2.65930

0.976 g/cm³

<25 °C

121.05 °C @ Press: 10 Torr

50-51°C/1mm

1.4100

Miscible with water.

-20°C

0.28 mm Hg @ 25 deg C

22-39/23/24/25-23/24/25-11

36/37-45-16-7

SZ9090000

F,T

P264, P270, P301+P312, P330, P501

H302

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.|The IR and UV laser induced photodestruction of diisopropyl methylphosphonate ... was /examined/. The excimer lasers ArF (193 nm), KrF (248 nm), XeCl (308 nm), quadrupled Nd:YAG (266 nm) and pulsed CO2 laser were used. Samples were irradiated in the vapor and liquid phases. Photodissociation was observed at all irradiation wavelengths, being most efficient when ArF irradiated diisopropyl methylphosphonate /was/ in the vapor phase in the air or O2. Pulsed, focused CO2 radiation led to multiple photon dissociation and pyrolytic destruction. Light hydrocarbon gases were the principal decomposition products. H2, CO, CO2 and water were also detected. The residual liquid is likely to be a P bearing acid.

McPhillips DM et al; J Biomed Mater Res 17 (6): 993-1002 (1983). Grafted synthetic sorbents for enhanced removal of toxic agents from plasma /including diisopropyl methylphosphonate/.

|Warning|H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]|P264, P270, P280, P301+P312, P305+P351+P338, P330, P337+P313, and P501|Aggregated GHS information provided by 76 companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Effective procedures associated with storage and disposal of chemical warfare (CW) agents are important for the protection of civilian populations from inadvertent release of these agents. Emergency groups as well as citizens in surrounding communities need to know the relative effectiveness of various chemical protective clothing (CPC) ensembles in the unlikely event of such releases. A method has beeen developed for studying permeation of chemical warfare agent simulants through chemical protective clothing materials. The experimental results characterize some commercially available chemical protective clothing materials. Thirteen different chemical protective clothing materials having widely differing compositions were chosen to study the permeation of four different liquid chemical warfare simulants (dimethyl methyl phosphonate, diisopropyl methyl phosphonate, malathion, and dibutyl sulfide) through these chemical protective clothing materials at 25 °C. This permeation study involved a newly developed analytical technique employing room temperature fluorescence quenching of an indicator compound, phenanthrene, on filter paper. Various experimental factors such as breakthrough time, rate of permeation and uptake were investigated. on the basis of breakthrough time, the 13 chemical protective clothing materials could be divided into three groups: most resistant, moderately resistant, and least resistant. Materials in the most resistant category exhibited no permeation by any of the simulants for at least 24 hours. Breakthrough occurred in the least resistant materials in generally less than an hour, and sometimes as soon as a few minutes.

Diisopropyl methylphosphonate is a chemical by-product resulting from the manufacture of Sarin (GB), a nerve gas that was produced by the Army in the 1950s. A chemical by-product is a chemical that is formed while making another substance. Sarin was produced and stored only in the Rocky Mountain Arsenal outside of Denver, Colorado. Production of Sarin in the United States was discontinued in 1957. Diisopropyl methylphosphonate is not known to occur naturally in the environment. It is not likely to be produced in the United States in the future because of the signing of a chemical treaty that bans the use, production, and stockpiling of poison gases. Diisopropyl methylphosphonate is a colorless liquid. Other names for it are DIMP, diisopropyl methane-phosphonate, phosphonic acid, and methyl-bis-(1-methylethyl)ester.

Diisopropyl methylphosphonate concns in brine effluent from GB chemical agent disposal ranged from 9 to 31 ppb(1).

Diisopropyl methylphosphonate was qualitatively identified in soil where the chemical warfare agent sarin was believed to have been used(1). Soil collected at the Rocky Mountain Arsenal in January 1978 and August 1979 contained the following concns of diisopropyl methylphosphonate: Pit #1 - 0.10, 0.11 ppm; Pit #4 - 1.71, 9.10 ppm; Lake F - 0.54 ppm, North Bog 0.050 ppm(2).

LD50 Rat oral 826 mg/kg|LD50 Male mouse (Swiss-Webster) oral 1041 mg/kg|LD50 Female mink oral 503 mg/kg|LD50 Male New Zealand rabbit dermal 1100 mg/kg

... Diisopropyl methylphosphonate is a by product of the manufacture of /nerve agent/ sarin.|Diisopropyl methylphosphonate is not produced commercially. It is a byproduct in the production of the chemical agent sarin (GB), constituting up to 20% of the chemical agent(1,2), and may also be used to simulate G-type chemical agents(3), and may be released to the environment through various waste streams.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 87(SRC), determined from a log Kow of 1.03(2) and a regression-derived equation(3), indicates that diisopropyl methylphosphonate is expected to have high mobility in soil(SRC). Volatilization of diisopropyl methylphosphonate from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 4.4X10-5 atm-cu m/mole(SRC), derived from its vapor pressure, 0.28 mm Hg(5), and water solubility, 1.5X10+3 mg/l(5). One volatilization study indicated that 5% and 22% of diisopropyl methylphosphonate applied to dry and moist soil, respectively, volatilized in 10 days(4). Biodegradation in soil is extremely slow; reported half-lives are 1 and 3 years, for acclimated and unacclimated soil, respectively(6). When 1 mg samples of sarin (GB) (containing diisopropyl methylphosphonate as an impurity) were placed on a snow surface and analyzed for persistence after 2 and 4 weeks, the diisopropyl methylphosphonate in the samples were in the range of 10-100% of the initial concns at both sampling periods(7). Diisopropyl methylphosphonate deposited on soil and maintained in an environmental chamber at 25 °C under tungsten light had an half-life of 26 to 28 days(4). The most likely process responsible for the loss of diisopropyl methylphosphonate is volatilization(4). The half-lives after deposition on foliar surfaces under 65% full sunlight, as opposed to tungsten light, was 4.2 days and 3.6 days for tall fescue grass and short-needle pine, respectively(8). The decreased half-life in grass versus soil may have resulted from increased volatilization due to increased surface area of grass compared with soil or the contribution of an enzymatically-mediated degradative process(8).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 87(SRC), determined from a log Kow of 1.03(2) and a regression-derived equation(3), indicates that diisopropyl methylphosphonate 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 4.4X10-5 atm-cu m/mole(SRC), derived from its vapor pressure, 0.28 mm Hg(7), and water solubility, 1.5X10+3 mg/l(7). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 31 hrs and 13 days, respectively(SRC). Diisopropyl methylphosphonate does hydrolyze, primarily by a base-catalyzed reaction resulting in isopropanol and isopropyl methylphosophonate(4). Using data from two studies(4,9) and extrapolation(SRC), hydrolysis is very slow and will not be important at environmental pHs and temperatures. One study indicated that biodegradation did not occur in natural water during a 12 week period(8). According to a classification scheme(5), an estimated BCF of 1.2(SRC), from its log Kow(2) and a regression-derived equation(6), 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 methylphosphonate, which has a vapor pressure of 0.28 mm Hg at 25 °C(2), is expected to exist solely in the vapor-phase in the ambient atmosphere. Vapor-phase diisopropyl methylphosphonate 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). Diisopropyl methylphosphonate does not absorb radiation >290 nm; therefore, direct photolysis cannot occur(4). Indirect photolysis is insignificant in regard to diisopropyl methylphosphonate's environmental fate in Rocky Mountain Arsenal water; diisopropyl methylphosphonate did not photolyze in either distilled or Rocky Mountain Arsenal water, when exposed to light (>290 nm) for 232 hours (9.7 days)(5).

The rate constant for the vapor-phase reaction of diisopropyl methylphosphonate 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 methylphosphonate is a weak UV absorber with absorption bands at 200 and 250 nm; the absorptivity is less than 0.1 L/mole-cm at 250 nm(2). There is no absorption >290 nm; therefore, direct photolysis cannot occur. Earlier studies showing an absorption tail extending into the near UV-visible region(3) were in error. Diisopropyl methylphosphonate (DIMP) did not photolyze in either distilled or Rocky Mountain Arsenal water, when exposed to light (>290 nm) for 232 hours (9.7 days)(3). Thus, indirect photolysis is insignificant in regard to diisopropyl methylphosphonate's environmental fate in Rocky Mountain Arsenal water. Hydrolysis of diisopropyl methylphosphonate is extremely slow. Extrapolations from rate measurements at elevated temperatures indicate a hydrolytic half-life of 663,000 years at pH 7 and 25 °C(4). The hydrolysis products are isopropanol and the half ester(4). The basic and acid rate constants extrapolated to 25 °C are 3.2X10-7 and 6.4X10-9 l/mole-sec, respectively(4). Another investigator obtained hydrolysis rate constants for diisopropyl methylphosphonate in water at 98 °C, 90 °C, and 80 °C of 2.0X10-6, 0.88X10-6, and 0.31X10-6 sec-1, respectively(5). The activation energy and ln A derived from these data are 26.9 and 10.17 kcal/mole, respectively. The half-life is 26 days at 80 °C. Extrapolation to 25 °C yields a half-life of 79 yrs(SRC). While these half-lives are very different, both indicate that hydrolysis will not be a significant loss process(SRC).

An estimated BCF of 1.2 was calculated for diisopropyl methylphosphonate(SRC), using a log Kow of 1.03(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. Experimental results with bluegill sunfish confirm that diisopropyl methylphosphonate does not bioconcentrate in fish(5). Diisopropyl methylphosphonate did not concentrate in the adipose tissue of ducks or quail(4). The lack of bioconcentration may be a result of metabolism, which is known to occur in mammals and birds(6,7).

The Koc of diisopropyl methylphosphonate is estimated as 87(SRC), using a log Kow of 1.03(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that diisopropyl methylphosphonate is expected to have high mobility in soil. A 13% reduction in diisopropyl methylphosphonate concn occurred when diisopropyl methylphosphonate-containing medium was circulated for 32 days in a soil percolator to acclimate the soil microorganisms(5). The investigators speculated that adsorption, rather than biodegradation, was responsible for the diisopropyl methylphosphonate reduction because no further diisopropyl methylphosphonate loss occurred during an additional 18 weeks of operation(5). The mobility of diisopropyl methylphosphonate in soil is evidenced by the detection of diisopropyl methylphosphonate in groundwater at the Rocky Mountain Arsenal(4,6). The source of contamination was a waste-disposal pond.

The Henry's Law constant for diisopropyl methylphosphonate is estimated as 4.4X10-5 atm-cu m/mole(SRC) derived from its vapor pressure, 0.28 mm Hg(1), and water solubility, 1.5X10+3 mg/l(1). This Henry's Law constant indicates that diisopropyl methylphosphonate 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 31 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 13 days(SRC). Diisopropyl methylphosphonate's estimated Henry's Law constant(1) indicates that volatilization from moist soil surfaces may occur(SRC). Diisopropyl methylphosphonate is expected to volatilize slowly from dry soil surfaces(SRC) based upon a vapor pressure of 0.28 mm Hg(1). In a study of the volatilization of diisopropyl methylphosphonate from soil, 20 ppm of radiolabeled diisopropyl methylphosphonate was mixed with dry or moist soil in 4 inch deep columns and air was directed across the soil surface(3). After approximately 250 hours (10.4 days), the dry soil retained 95% of the initial radioactivity while the moist soil retained 78%(3). During a soil biodegradation test, 19% of the 14-C-diisopropyl methylphosphonate volatilized from the soil biometer test during the 34 weeks of incubation(4). When diisopropyl methylphosphonate was applied to corn and sugarbeet leaves, 96-97% and 91% volatilized within 24 hr, respectively(5).

Diisopropyl methylphosphonate ... has been detected as a ground water contaminant in Colorado.|SURFACE WATER: In May 1974, diisopropyl methylphosphonate was detected in surface water draining from a marshy bay on the northern boundary of the Rocky Mountain Arsenal(1). Diisopropyl methylphosphonate concns in groundwater at the Rocky Mountain Arsenal ranged from 0.5 ppb, the analytical detection limit, to 44,000 ppb near an abandoned waste-disposal pond(2). The pond received effluent between 1952 and 1956. When the measurements were made in 1974, groundwater contamination covered 73 sq km, spreading beyond the boundaries of the Arsenal. The concn of diisopropyl methylphosphonate measured in water in the North Bog of the arsenal in January 1979 was 0.26 - 0.27 ppm(3). Isopropyl methylphosphonic acid (IMPA) can disproportionate on a GC column to form diisopropyl methylphosphonate and methylphosphonic acid (MPA)(4). Therefore, the detection of diisopropyl methylphosphonate may be an artifact of the analytical system, unless IMPA is removed during sample preparation.

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

... Three dose levels of diisopropyl methylphosphonate were applied to a shaved area on the backs of Yorkshire-Cross pigs: 400, 40, and 4 ug/sq cm. Additional animals were given 40 mg of diisopropyl methylphosphonate by sc injection, which was equivalent to the high dose applied dermally. Within 24 hr of injection, 91% of the sc administered dose was eliminated in the urine. After 5 days, no further amt was detected in the urine. All tissue specimens collected revealed less than 0.04 ug/g of tissue. For those pigs treated dermally, the total absorbed dose was less than 7% of that applied after 7 days. Over 80% of the absorbed dose was recovered from the urine within 24 hr of treatment. No accumulation in any specific organs could be detected. ...|Single doses (225 mg/kg) of [14C]-radiolabeled diisopropyl methylphosphonate dissolved in polyethylene glycol were admin by gavage to fasted male mice, rats, and dogs ... In mice, the highest level of radioactivity (172 ug/ml) was noted in the blood at 15 min. In rats, plasma concn peaked at 151 ug/ml about 2 hr after cmpd admin ... In dogs, peak plasma concn also occurred at 2 hr post-admin at a concn of 276 ug/ml ... Approx 90% of the diisopropyl methylphosphonate was absorbed from the GI tract. This estimate is based on the small percentage of the label found in the feces in the 2-3-day period after dosing and the 84- 97% excreted in the urine ... .|Diisopropyl methylphosphonate is initially distributed to the liver by way of the portal circulation after absorption from the intestines, and then to the kidneys for excretion ... High concn of radiolabel were detected in the urinary bladder itself, exclusive of any urine of mice at 15 min and persisted for up to 6 hr. A similar pattern of distribution to the liver, kidney, and urinary bladder was seen in rats over the first 6 hr after oral admin of diisopropyl methylphosphonate.|Urine is the principal excretory route for elimination of diisopropyl methylphosphonate after oral admin to mice, rats, pigs, mink, or dogs ... Peak urinary excretion of a single oral dose of 225 mg/kg [14C]- radiolabeled dissiopropyl methylphosphonate occurred at 6 hr in mice, 24 hr in rats, and 72 hr in dogs ... Over the 72-hr period after dosing, a total of 96% of the recovered label was found in the urine of mice, 86% of the recovered label was found in the urine of rats, and 97% was found in the urine of dogs. Fecal excretion was low in some species (3- 30%). Only 0.06% of the label was found in the bile of dogs; biliary excretion in mice and rats was not determined. Minimal label (<0.5%) was removed from the body with exhaled air.

Two metabolites of dissiopropyl methylphosphonate are isopropyl methylphosphonic acid (IMPA) and methylphosphonic acid (MPA). Excretion of these metabolites in animals occurs primarily through the urine.|This study reports the metabolism of carbon-14labeled diisopropyl methylphosphonate (DIMP) in mink and rats, undertaken to better understand the dose-related mortality reported for mink in a previous study. In both male and female mink and rats, diisopropyl methylphosphonate was rapidly absorbed after oral administration; it was metabolized by a saturable pathway to a single metabolite, isopropyl methylphosphonate (IMPA), which was rapidly excreted, primarily in the urine (90%). Fecal radioactivity, also identified as isopropyl methylphosphonate, was 1.7-3.1% of the administered dose. Female rats had a slower rate of conversion of diisopropyl methylphosphonate to isopropyl methylphosphonate and less total excretion of isopropyl methylphosphonate than male rats. Metabolism of diisopropyl methylphosphonate administered intravenously was not very different from that given orally in both species. These data indicate that mink absorb, metabolize, and excrete diisopropyl methylphosphonate (as IMPA) in a manner very similar to mice, rats, and dogs.|Diisopropyl methylphosphonate is metabolized in mammals(1,2) and birds(1). After dosing ducks, quail and mink the biological half-life of diisopropyl methylphosphonate was 12.7 hours(2).

No studies were located for reducing absorption in humans or animals exposed to diisopropyl methylphosphonate. Standard methods such as cathartics or activated carbon could be used. However, exposure would have to be identified within 4-6 hr since diisopropyl methylphosphonate is rapidly absorbed for the GI tract ... Common methods for reducing dermal absorption ... incl removing contaminated clothes and washing contacted skin with soap and water ... Following eye contact ... eyes should be flushed with copious amt of water.

More than 5000 passengers of Tokyo subway trains were injured with toxic chemicals including the nerve gas sarin. Most of the victims examined had marked miosis and decreased serum cholinesterase activity. To monitor the genetic aftereffects of sarin exposure, we measured sister chromatid exchanges (SCEs) of the victims using peripheral blood lymphocytes. The frequency of sister chromatid exchanges was significantly higher in the victims than in the control group. Analyzing results using samples of urine from the victims suggested that the victims were exposed to not only sarin per se, but by-products of sarin synthesis, i.e. diisopropyl methylphosphonate (DIMP), diethyl methylphosphonate (DEMP) and ethyl isopropyl methylphosphonate (EIMP). Thus, the in vitro SCE-inducing effect of diisopropyl methylphosphonate, diethyl methylphosphonate and ethyl isopropyl methylphosphonate was examined using human lymphocytes and we obtained positive results.

diisopropyl methylphosphonate

Hematological (Blood Forming)

Phosphonic acid, P-methyl-, bis(1-methylethyl) ester: ACTIVE|Diisopropyl methylphosphonate is a byproduct from the manufacture of the nerve-agent Sarin|Constitutes up to 20% of Sarin

Interdigitated gate electrode field effect transistor for the selective detection of nitrogen dioxide and diisopropylmethylphosphonate.|Supercritical fluid extraction of chemical warfare agent simulants from soil /including diisopropyl methylphosphonate/.|Detection of gaseous organophosphates /including diisopropyl methylphosphonate/ using secondary ion mass spectrometry.