2-Chlorobenzylidenemalononitrile

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

Use powder, carbon dioxide.

Fresh air, rest.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Give one or two glasses of water to drink. Refer for medical attention .

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

(General first aid procedures)

1. VENTILATE AREA OF SPILL. 2. FOR SMALL QUANTITIES, SWEEP ONTO PAPER OR OTHER SUITABLE MATERIAL, PLACE IN APPROPRIATE CONTAINER & BURN IN SAFE PLACE (SUCH AS FUME HOOD). LARGE QUANTITIES MAY BE RECLAIMED; HOWEVER, IF THIS IS NOT PRACTICAL, DISSOLVE IN FLAMMABLE SOLVENT (SUCH AS ALCOHOL) & ATOMIZE IN SUITABLE COMBUSTION CHAMBER EQUIPPED WITH APPROPRIATE EFFLUENT GAS CLEANING DEVICE. 3. DECONTAMINATE AREA OF SPILL: (A) BY WASHING WITH A 5% SOLUTION OF SODIUM HYDROXIDE IN 50/50 ETHYL ALCOHOL/WATER; OR (B) BY ADDING FLAKE SODIUM HYDROXIDE TO A SOLUTION OR SLURRY OF THE SPILL IN ISOPROPYL ALCOHOL; OR (C) BY COVERING THE SPILL WITH A 10% SOLUTION OF SODIUM HYDROXIDE IN 50/50 ISOPROPYL ALCOHOL/WATER & LETTING STAND 20 MINUTES BEFORE FLUSHING WITH WATER.

CHEMICAL DISPOSAL METHOD FOR CS WAS DEVELOPED. THE RECOMMENDED REACTION IS AQ ALKALINE HYDROLYSIS OF CS TO O-CHLOROBENZALDEHYDE.

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.

1. BY MAKING PACKAGES OF O-CHLOROBENZYLIDENE MALONONITRILE IN PAPER OR OTHER FLAMMABLE MATERIAL & BURNING IN SUITABLE COMBUSTION CHAMBER EQUIPPED WITH AN APPROPRIATE EFFLUENT GAS CLEANING DEVICE. 2. BY DISSOLVING O-CHLOROBENZYLIDENE MALONONITRILE IN FLAMMABLE SOLVENT (SUCH AS ALCOHOL) & ATOMIZING IN SUITABLE COMBUSTION CHAMBER EQUIPPED WITH APPROPRIATE EFFLUENT GAS CLEANING DEVICE. 3. BY MIXING SOLID WITH 5 PARTS OF 10% SOLUTION OF MONOETHANOLAMINE IN WATER CONTAINING 0.3% OF NONIONIC DETERGENT. 4. BY STIRRING 1 LB OF SOLID FOR 2 HOURS IN 1 GALLON OF A 5-15% SOLUTION OF SODIUM HYDROXIDE IN ETHYLENE GLYCOL, ETHYL ALCOHOL, OR METHYL ALCOHOL.

The worker should immediately wash the skin when it becomes contaminated.

The worker should wash daily at the end of each work shift.

Work clothing that becomes wet or significantly contaminated should be removed or replaced.

Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises.

For more Preventive Measures (Complete) data for 2-CHLOROBENZALMALONONITRILE (6 total), please visit the HSDB record page.

When CS is applied in a solvent, its effect on the cornea is very much influenced by the nature of the solvent, less injury resulting from solutions in trichloroethane or tri(2-ethylhexyl)phosphate than in methylene dichloride, corn oil, or polyethylene glycol 300.

The toxic mechanism of nitriles and the effect of metabolic modifiers in mice were studied in relation to their physicochemical properties. All the test nitriles liberated cyanide both in vivo and in vitro, with the exception of benzonitrile, although the extent of liberation and the effect of carbon tetrachloride pretreatment on the mortality of animals differed among nitriles. From these results, test compounds were tentatively divided into 3 groups. In group 1, acute toxicity was greatly reduced by carbon tetrachloride pretreatment, in group 2, toxicity was not significantly changed or was somewhat enhanced, and in group 3, benzonitrile only, toxicity was clearly enhanced. The amount of cyanide was higher at death in the brains of mice given group 1 compounds, the level being comparable to that found in mice killed by dosing with potassium cyanide. The relation between log (1/LD50) and log p for the compounds in group 1 fitted a parabolic plot, while that for compounds in group 2 was linear. For most nitriles, the in vitro metabolism was inhibited when the incubation mixture contained either SKF-525A, carbon monoxide, or microsomes from mice treated with carbon tetrachloride. When mice were dosed with ethyl alcohol, metabolic enhancement of nitriles was seen compared with the control. However, ethyl alcohol, when added to the incubation mixture, inhibited the in vitro metabolism of nitriles. /Nitriles/

LC50 Rainbow trout 1.28 mg/l/12 hr. /Conditions of bioassay not specified/

LC50 RAINBOW TROUT > 0.1 MG/L < 1 WK.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 1700(SRC), determined from a structure estimation method(2), indicates that 2-chlorobenzalmalononitrile is expected to have low mobility in soil(SRC). 2-Chlorobenzalmalononitrile was applied to snow surfaces in a Norwegian forest; more than 10% remained after 28 days(5). 2-Chlorobenzalmalononitrile was found in Norwegian snow samples 70 m downwind and for as long as 29 days following the detonation of a grenade containing this compound(5). Dusts or powders of 2-chlorobenzalmalononitrile that have settled to the ground after its use as a riot control agent can remain active for as long as 5 days(6); if the compound was formulated with a silicone water repellent, it may persist for as long as 45 days(6). Volatilization of 2- chlorobenzalmalononitrile from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.0X10-8 atm-cu m/mole(SRC), using a fragment constant estimation method(3). The major degradation process for 2-chlorobenzalmalononitrile in moist soil is expected to be hydrolysis(SRC); half-lives of 281.7 min at 0 °C and 14.5 min at 25 °C have been determined(7). Actual environmental degradation rates may be much slower because the rate at which 2-chlorobenzalmalononitrile dissolves in water can be very slow(7). 2-Chlorobenzalmalononitrile is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 3.4X10-5 mm Hg(4).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 1700(SRC), determined from an estimation method(2), indicates that 2-chlorobenzalmalononitrile is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 1.0X10-8 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). 2-Chlorobenzalmalononitrile is expected to hydrolyze in aquatic environments forming 2-chlorobenzaldehyde. Aqueous hydrolysis experiments in seawater have determined hydrolysis half-lives of 281.7 min at 0 °C and 14.5 min at 25 °C(8). However, actual environmental degradation rates may be much slower because the rate at which 2-chlorobenzalmalononitrile dissolves in water can be very slow(8). 2-Chlorobenzalmalononitrile released to water could float and travel for considerable distances before it dissolves(8); once it is dissolved, hydrolysis will proceed rapidly. Bioconcentration is not expected when 2-chlorobenzalmalononitrile is present in the dissolved form as hydrolysis will occur so rapidly(SRC). According to a classification scheme(5), an estimated BCF of 30(SRC), from an estimated log Kow of 2.76(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low. Aquatic volatilization and adsorption to sediment are not expected to be environmentally important(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-chlorobenzalmalononitrile, which has a vapor pressure of 3.4X10-5 mm Hg at 20 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase 2-chlorobenzalmalononitrile 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 110 hrs(SRC), calculated from its rate constant of 3.5X10-12 cu cm/molecule-sec at 25 °C(3) determined using a structure estimation method(3). Particulate-phase 2-chlorobenzalmalononitrile may be removed from the air by wet and dry deposition(SRC). 2-Chlorobenzalmalononitrile when dissolved in water is susceptible to rapid hydrolysis; half-lives range from 281.7-14.5 minutes at 0-25 °C(4). Therefore, dissolution of the compound into clouds or rain will contribute to its atmospheric removal(SRC).

The substance can be absorbed into the body by inhalation, through the skin and by ingestion.

inhalation, skin absorption, ingestion, skin and/or eye contact

Organic nitriles decompose into cyanide ions both in vivo and in vitro. Consequently the primary mechanism of toxicity for organic nitriles is their production of toxic cyanide ions or hydrogen cyanide. Cyanide is an inhibitor of cytochrome c oxidase in the fourth complex of the electron transport chain (found in the membrane of the mitochondria of eukaryotic cells). It complexes with the ferric iron atom in this enzyme. The binding of cyanide to this cytochrome prevents transport of electrons from cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted and the cell can no longer aerobically produce ATP for energy. Tissues that mainly depend on aerobic respiration, such as the central nervous system and the heart, are particularly affected. Cyanide is also known produce some of its toxic effects by binding to catalase, glutathione peroxidase, methemoglobin, hydroxocobalamin, phosphatase, tyrosinase, ascorbic acid oxidase, xanthine oxidase, succinic dehydrogenase, and Cu/Zn superoxide dismutase. Cyanide binds to the ferric ion of methemoglobin to form inactive cyanmethemoglobin. (L97)

Cough. Dizziness. Headache. Laboured breathing. Nausea. Sore throat. Vomiting.

Redness. Burning sensation. Pain. Blisters.

Watering of the eyes. Redness. Pain.

Burning sensation in the throat and chest.

Pain, burn eyes, lacrimation (discharge of tears), conjunctivitis; erythema (skin redness) eyelids, blepharospasm; irritation throat, cough, chest tightness; headache; erythema (skin redness), vesiculation skin

Symptoms include eye irritation, tearing, burning sensation on the nose and throat, rhinorrhoea, excess salivation, constricting sensations in the chest, sneezing, coughing, and stinging or burning sensations in exposed skin.

The following link will take the user to the National Toxicology Program (NTP) Test Agent Search Results page, which tabulates all of the "Standard Toxicology & Carcinogenesis Studies", "Developmental Studies", and "Genetic Toxicity Studies" performed with this chemical. Clicking on the "Testing Status" link will take the user to the status (i.e., in review, in progress, in preparation, on test, completed, etc.) and results of all the studies that the NTP has done on this chemical. [http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchresults&searchterm=2698-41-1]

Using a structure estimation method based on molecular connectivity indices(1), the Koc for 2-chlorobenzalmalononitrile can be estimated to be 1700(SRC). According to a classification scheme(2), this estimated Koc value suggests that 2-chlorobenzalmalononitrile is expected to have low mobility in soil.

Occupational exposures can occur during the manufacturing and formulation of OCBM for a riot control agent; [NIOSH Guidelines for Chemical Hazards]

IT IS USED PRIMARILY AS AN INCAPACITATING AGENT, BOTH BY MILITARY & LAW ENFORCEMENT PERSONNEL. IT CAN BE DISSEMINATED IN BURNING GRENADES & WEAPON-FIRED PROJECTILES, AS AN AEROSOL FROM THE FINELY DIVIDED SOLID CHEMICAL, OR FROM A SOLUTION OF THE CHEMICAL DISSOLVED IN METHYLENE CHLORIDE OR ACETONE.

Riot control agent.

... lachrymatory chemical used for self-defense devices.

CS is a sensory irritant whose moderate degree of toxicity has led to its use as a riot/adversary control agent. Major exposure symptoms include eye irritation, conjunctivitis, excess lacrimation, blepharospasm, burning sensation in the nose and throat, chest tightness, sneezing and coughing, stinging or burning sensations on the exposed skin and possible skin sensitization.

o-Chlorobenzaldehyde + malononitrile (carbonyl condesation)

Prepn: B.B. Corson, R.W. Stoughton, J Am Chem Soc 50: 2825 (1928)