Carbonimidic dichloride, hydroxy-

Toxic Gases & Vapors -> Chemical Weapons

-> NIOSH Emergency Response Categories

Disagreeable, penetrating odor

Intense, penetrating, disagreeable and violently irritating odor

Colorless prismatic crystals

Colorless solid or yellowish-brown liquid

128 °C at 760 mm Hg

Boiling point: 53-54 °C at 24 mm Hg. Decomposes slowly at ambient temperatures.

11.2 [mmHg]

11.2 mm Hg at 25 °C (solid); 13 mm Hg at 40 °C (liquid)

11.2 [mm Hg] @25 °C

Phosgene oxime appears as a chemical warfare blister agent. Colorless liquid, odorless to fruity.

Colorless, crystalline solid or liquid with an "intense, irritating" odor;

Colorless, crystalline solid or yellowish-brown liquid.

It decomposes when in contact with many metals, but it also is corrosive to most metals.

Volatility: 1800 mg/ cu m at 20 °C

Danger

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

P260, P261, P262, P264, P270, P271, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P319, P320, P321, P330, P361+P364, P363, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 2 reports by companies from 1 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Phosgene oxime is a manufactured chemical that was developed as a potential chemical warfare agent, but its use on the battlefield has never been documented. It has a disagreeable penetrating odor. Pure phosgene oxime is a colorless, crystalline solid; the munitions grade compound is a yellowish-brown liquid. Both the liquid and the solid can give off vapors at ambient temperatures.

It causes immediate pain and urticaria followed by tissue destruction after skin contact. Inhalation causes pulmonary edema. It penetrates clothing and rubber faster than other military agents. [ccc.apgea.army.mil] It is a solid below 95 degrees F. The liquid is yellowish brown with a strong odor. Wheals form within 30 minutes, and tissue necrosis occurs within 24 hours. Heavy exposure may cause eye injury and blindness. There are no specific diagnostic tests. The chest x-ray may show pulmonary edema. [Weinstein, p. 140] Mp = 39-40 deg C; Pulmonary edema may also result from skin absorption; Although not a true vesicant, causes extensive tissue damage; Estimated dermal LD50 is 25 mg/kg; [HSDB]

Phosgene oxime is an oxime. Chemically similar to, but more reactive than an amide. Incompatible with strong acids and bases, and especially incompatible with strong reducing agents such as hydrides. Also incompatible with strongly oxidizing acids, peroxides, and hydroperoxides.

/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Health: TOXIC; inhalation, ingestion, or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Fire or Explosion: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.

/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Public Safety: CALL Emergency Response Telephone Number ... . 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. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. Ventilate enclosed areas.

/GUIDE 154: SUBSTANCES - TOXIC AND/OR CORROSIVE (NON-COMBUSTIBLE)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible.

For more DOT Emergency Guidelines (Complete) data for PHOSGENE OXIME (8 total), please visit the HSDB record page.

For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

- Phosgene oxime is non-combustible.

If material on fire or involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use water in flooding quantities as fog. Use "alcohol" foam, dry chemical or carbon dioxide. /Toxic solids, organic, NOS/

Principles and methods for destruction of chemical weapons: ... "Destruction of chemical weapons" means a process by which chemicals are converted in an essentially irreversible way to a form unsuitable for production of chemical weapons, and which in an irreversible manner renders munitions and other devices unusable as such. ... Each State Party shall determine how it shall destroy chemical weapons, except that the following processes may not be used: dumping in any body of water, land burial or open-pit burning. It shall destroy chemical weapons only at specifically designated and appropriately designed and equipped facilities. ... Each State Party shall ensure that its chemical weapons destruction facilities are constructed and operated in a manner to ensure the destruction of the chemical weapons; and that the destruction process can be verified under the provisions of this Convention.

Responders should be trained and appropriately attired before entering the Hot Zone. If the proper personal protective equipment (PPE) is not available, or if the rescuers have not been trained in its use, call for assistance in accordance with local Emergency Operational Guides (EOG).... /In the Decontamination Zone, rescuers/ should continue to wear the same level of protection as required in the Hot Zone

Decontamination or self-aid immediately after skin and ocular exposure is the only means for preventing or decreasing tissue damage since phosgene oxime is absorbed within seconds. Decontaminable gurneys and back boards should be used if available when managing casualties in a contaminated area. ... The eyes and skin must be decontaminated immediately after exposure because the agent is absorbed from the skin within seconds. Flush the eyes immediately with water for about 5 to 10 minutes by tilting the head to the side, pulling eyelids apart with fingers, and pouring water slowly into eyes. Do not cover eyes with bandages.

Persons whose clothing or skin is contaminated with liquid or solid phosgene oxime can cause secondary contamination by direct contact or through off-gassing vapor. Persons exposed only to phosgene oxime vapor pose no risk of secondary contamination. ... Before transport, all casualties must be decontaminated. ...

If contaminated patients arrive at the Emergency Department, they must be decontaminated before being allowed to enter the facility. Decontamination can take place inside the hospital only if there is a decontamination facility with negative air pressure and floor drains to contain contamination. Personnel should wear the same level of protection required in the Hot Zone. Victims who have undergone decontamination or have been exposed only to phosgene oxime vapor pose no serious risk of secondary contamination to rescuers. In such cases, Support Zone personnel require no specialized protective gear.

For more Preventive Measures (Complete) data for PHOSGENE OXIME (13 total), please visit the HSDB record page.

0.028 [mg/m3]

0.083 [mg/m3]

13 [mg/m3]

For information on chemical warfare blister agents see the ERG Criminal or Terrorist Use of CBR Agents. (ERG, 2024)

Pressure-demand, self-contained breathing apparatus (SCBA) is recommended in response situations that involve exposure to any level of phosgene oxime vapor. Personal Protective Equipment (PPE) and butyl rubber gloves must be worn at all times when skin contact with any form of the material is possible because lesions and dermal absorption may occur.

In liquid or vapor form it is highly corrosive /to skin and mucus membranes/, and it penetrates clothing and rubber readily.

Skin/Ocular Protection /for emergency rescuers/: Personal Protective Equipment (PPE) and butyl rubber gloves must be worn at all times when skin contact with any form of the material is possible because lesions and dermal absorption may occur. Phosgene oxime may attack the butyl rubber in the butyl rubber gloves and boots, which nevertheless, are expected to protect against field concentrations of phosgene oxime until they can be exchanged for fresh gloves and boots.

GENERAL INFORMATION

AEGL 1: Notable discomfort, irritation, or certain asymptomatic non-sensory effects. However, the effects are not disabling and are transient and reversible upon cessation of exposure (Unit: mg/m3)

0.17 mg/m3

0.056 mg/m3

0.028 mg/m3

0.0069 mg/m3

0.0035 mg/m3

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 68(SRC), determined from a structure estimation method(2), indicates that phosgene oxime is expected to have high mobility in soil(SRC). Phosgene oxime is a weak acid with an estimated pKa of 6.5(3). This estimated pKa indicates phosgene oxime will partially exist as an anion in the environment. Volatilization from moist soil is not expected since anions do not volatilize and the estimated Henry's Law constant for the neutral species is 5.5X10-7 atm-cu m/mole(SRC) derived using a fragment constant estimation method(4). The potential to volatilize from dry soil surfaces exists based on a vapor pressure of 11.2 mm Hg at 25 °C(5). Phosgene oxime was reported to hydrolyze in water(6), indicating hydrolysis in moist soils may also be possible. Biodegradation data were not available(SRC, 2008).

TERRESTRIAL FATE: To assess the feasibility of contaminated debris disposal in municipal solid waste (MSW) landfills, the fate of selected chemical warfare agents (CWAs) and toxic industrial chemicals (TICs) in MSW landfills was predicted with a mathematical model. Five blister agents [sulfur mustard (HD), nitrogen mustard (HN-2), lewisite (L), ethyldichloroarsine (ED), and phosgene oxime (CX)], eight nerve agents [tabun (GA), sarin (GB), soman (GD), GE, GF, VX, VG, and VM], one riot-control agent [CS], and two TICs [furan and carbon disulfide] were studied. The effects of both infiltration (climate) and contaminant biodegradability on fate predictions were assessed. Model results showed that hydrolysis and gas-phase advection were the principal fate pathways for CWAs and TICs, respectively. Apart from CX and the TICs, none of the investigated compounds was predicted to persist in a landfill for more than 5 years. Climate had little impact on CWA/TIC fate, and biodegradability was only important for compounds with long hydrolysis half-lives. Monte Carlo simulations were performed to assess the influence of uncertainty in model input parameters on CWA/TIC fate predictions. Correlation analyses showed that uncertainty in hydrolysis rate constants was the primary contributor to variance of CWA fate predictions, while uncertainty in the Henry's Law constant and landfill gas-production rate accounted for most of the variance of TIC fate predictions. CWA hydrolysates were more persistent than the parent CWAs, but limited information is available on abiotic or biotic transformation rates for these chemicals.

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 68(SRC), determined from a structure estimation method(2), indicates that phosgene oxime is not expected to adsorb to suspended solids and sediment(SRC). Phosgene oxime is a weak acid with an estimated pKa of 6.5(3). This estimated pKa indicates phosgene oxime will partially exist as an anion in water. Volatilization from water is not expected since anions do not volatilize and the estimated Henry's Law constant for the neutral species is 5.5X10-7 atm-cu m/mole(SRC) derived using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of 3(SRC), from an estimated log Kow of 0.73(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). The hydrolysis half-life of phosgene oxime at an unspecified pH and temperature was reported as 83 days(8). Biodegradation data were not available(SRC, 2008).

AQUATIC FATE: Phosgene oxime belongs to a class of agents that dissolve slowly but completely in water, and may take days to decompose once they are in solution(1). Hydrolysis is likely the most important fate of phosgene oxime in water(SRC). Volatilization from water surfaces or bioconcentration in aquatic species are not expected to be important fate processes for phosgene oxime(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), phosgene oxime, which has a vapor pressure of 11.2 mm Hg at 25 °C(2), is expected to exist solely in the vapor-phase in the ambient atmosphere. Phosgene oxime does not contain functional groups that are susceptible to degradation by reaction with photochemically generated hydroxyl radicals or ozone(3). Vapor-phase phosgene oxime may be removed from air by wet and dry deposition(SRC). Phosgene oxime does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight(4). Phosgene oxime belongs to a class of agents

- Immediate pain, inflammation of the membranes (conjunctivitis), corrosion of the cornea (keratitis), excessive tear production (lacrimation), vision loss, and temporary blindness.

- Probable hemorrhagic inflammatory lesions and destruction of the lining of the gastrointestinal (GI) tract.

- Immediate and incapacitating irritation, pain, and local tissue destruction of the upper airways; difficulty breathing or shortness of breath (dyspnea); and cough.

- Immediate pain, whitening (blanching) of the skin surrounded by a red (erythematous) ring, local tissue death (necrosis), itching (pruritus), and hives (urticaria).

Routine laboratory studies should be done for all patients requiring admission. These include CBC, glucose, serum electrolytes, liver enzymes, and kidney function tests. Chest X-ray and pulse oximetry (or ABG measurements) are recommended for inhalation exposures.

Patients with moderate to severe exposures will require hospitalization. Routine laboratory studies should be done for all patients requiring admission. These include CBC, glucose, serum electrolytes, liver enzymes, and kidney function tests. Chest X-ray and pulse oximetry (or ABG measurements) are recommended for inhalation exposures.

Using a structure estimation method based on molecular connectivity indices(1), the Koc of phosgene oxime can be estimated to be 68(SRC). According to a classification scheme(2), this estimated Koc value suggests that phosgene oxime is expected to have high mobility in soil(SRC). Phosgene oxime belongs to a class of agents that are unstable and decompose rapidly in soil(3); therefore, it is likely that phosgene oxime would decompose in soil before it was able to leach to any extent(SRC).

/SIGNS AND SYMPTOMS/ Phosgene oxime is an urticant or nettle agent. ... Post World War II studies indicate that concentrations below 8% cause no or inconsistent effects.

/SIGNS AND SYMPTOMS/ Inhaled phosgene oxime is extremely irritating to the upper airways and causes pulmonary edema. Irritation occurs with exposures to 0.2 mg-min/cu m and becomes unbearable at 3 mg-min/cu m.

/SIGNS AND SYMPTOMS/ Direct contact with phosgene oxime results in immediate pain, irritation, and tissue necrosis. Inhalation and systemic absorption may result in pulmonary edema, necrotizing bronchiolitis, and pulmonary thrombosis. Contact with the eyes may result in severe pain, conjunctivitis, and keratitis.

/SIGNS AND SYMPTOMS/ The mechanism by which it damages tissue is unknown, but its effects are almost instantaneous and produce severe pain.

For more Human Toxicity Excerpts (Complete) data for PHOSGENE OXIME (12 total), please visit the HSDB record page.

An estimated BCF of 3 was calculated for phosgene oxime(SRC), using an estimated log Kow of 0.73(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(SRC). Phosgene oxime belongs to a class of agents that dissolve slowly but completely in water, and may take days to decompose once they are in solution(4).

Phosgene oxime is a weak acid with an estimated pKa of 6.5(1). This estimated pKa indicates phosgene oxime will partially exist as an anion in the environment. Volatilization from moist soil and water is not expected since anions do not volatilize and the estimated Henry's Law constant for the neutral species is 5.5X10-7 atm-cu m/mole(SRC) derived using a fragment constant estimation method(2). Phosgene oxime belongs to a class of agents that dissolve slowly but completely in water, and may take days to decompose once they are in solution(4). The potential to volatilize from dry soil surfaces exists based on a vapor pressure of 11.2 mm Hg at 25 °C(3).

/OTHER TOXICITY INFORMATION/ Animal studies suggest phosgene oxime may induce hemorrhagic inflammatory lesions in the gastrointestinal tract.

/OTHER TOXICITY INFORMATION/ Dichlorophormoxime (I) was synthesized and its irritant, physiological and pathological properties in animals were compared with those exhibited by mustard gas and lewisite. When administered by inhalation, it has a low toxicity in mice, rabbits and guinea pigs. Toxicity by cutaneous absorption (5 mg/100 g body weight) is high but lower than one of the vesicant gases. One drop of a 1.5% benzene solution of I causes erythema ...

Used as a military poison (blistering agent); [HSDB]

Military poison

Blistering agent

Phosgene oxime is an urticant (nettle agent). On contact with the skin, it causes redness (erythema) and hives (wheals and urticaria). Phosgene oxime does not produce blistering (vesication). Very little is known about the effects of phosgene oxime on humans; its mechanism of action is unknown. The effects of phosgene oxime vapor and liquid on the skin, eyes and lungs are almost instantaneous. No other chemical agent is capable of producing immediate extreme pain followed by rapid local tissue death (necrosis). Phosgene oxime was developed as a potential chemical warfare agent (military designation CX), but has not been used on the battlefield. Phosgene oxime is of military interest because it penetrates garments and rubber much more quickly than do other chemical agents. When mixed with other chemical agents (e.g., nerve agents), the rapid skin damage caused by phosgene oxime may make the skin more permeable to the second agent. It has a disagreeable, penetrating odor and a violently irritating vapor. The solid can release enough vapor to cause symptoms.