4-Chlorophenyl Isocyanate

Colorless to slightly yellow liquid or crystals

White solid or crystals

110 °C

230 °F

204 °C

BP: 116 °C at 45 mm Hg

95.4 [mmHg]

VP: 95.4 mm Hg at 20 °C

19.4 mm Hg at 25 °C (extrapolated)

P-chlorophenyl isocyanate appears as colorless to yellow liquid or crystals. Used as an intermediate in pesticide and pharmaceutical manufacture.

Colorless to yellow liquid or white solid; [Hawley] White crystalline solid; mp = 29-31 deg C; [MSDSonline]

Danger

H302: Harmful if swallowed [Warning Acute toxicity, oral]

P233, P260, P261, P264, P264+P265, P270, P271, P273, P280, P284, P301+P317, P302+P352, P304+P340, P305+P354+P338, P316, P317, P319, P320, P321, P330, P332+P317, P342+P316, P362+P364, P391, P403, P403+P233, P405, and P501 (click each P-code to see the statement)

Danger

H301 (32.6%): Toxic if swallowed [Danger Acute toxicity, oral]

P233, P260, P261, P264, P264+P265, P270, P271, P273, P280, P284, P301+P316, P301+P317, P302+P352, P304+P340, P305+P354+P338, P316, P317, P319, P320, P321, P330, P332+P317, P342+P316, P362+P364, P391, P403, P403+P233, P405, and P501 (click each P-code to see the statement)

Hazard Traits - Respiratory Toxicity

Status: Active Update: 03-12-2015 https://echa.europa.eu/registration-dossier/-/registered-dossier/1148

4-Chlorophenyl isocyanate: Does not have an individual approval but may be used under an appropriate group standard

A strong irritant of the skin and eyes; [Hawley] An irritant; May cause lacrimation and serious injury to eyes; May cause respiratory sensitization after prolonged contact; [MSDSonline] Could be carcinogenic for man but not conclusive because of insufficient data (3B); [MAK] See MONOISOCYANATES.

Section 8(a) of TSCA requires manufacturers of this chemical substance to report preliminary assessment information concerned with production, exposure, and use to EPA as cited in the preamble in 51 FR 41329. Effective date: 10/29/90; Reporting date: 12/27/90.

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Benzene, 1-chloro-4-isocyanato- is included on this list. Effective date: 10/29/90; Sunset date: 6/30/98.

Isocyanates and thioisocyanates are incompatible with many classes of compounds, reacting exothermically to release toxic gases. Reactions with amines, aldehydes, alcohols, alkali metals, ketones, mercaptans, strong oxidizers, hydrides, phenols, and peroxides can cause vigorous releases of heat. Acids and bases initiate polymerization reactions in these materials. Some isocyanates react with water to form amines and liberate carbon dioxide. Base-catalysed reactions of isocyanates with alcohols should be carried out in inert solvents. Such reactions in the absence of solvents often occur with explosive violence, [Wischmeyer(1969)].

Acute Tox. 3 (32.6%)

Specific target organ toxicity (single exposure) - category 3

Acute Tox. 2 *

Isocyanates are transported in railroad tank cars, tank trucks, tanks in ships, containers, and drums. They are stored in steel tanks and processed in steel equipment. For long-term storage stainless steel is recommended. To avoid contamination by atmospheric moisture, a dry air or inert gas blanket is essential. /Isocyanates/

Decontamination of spilled isocyanates and disposal of isocyanate waste are best conducted by using aqueous ammonia (3-8% concentrated ammonia solution in 90-95% water with 0.2-5% liquid detergent) or aqueous sodium carbonate (5-10% sodium carbonate in 90-95% water and 0.2-5% liquid detergent). An alcoholic solution (50% ethanol, isopropyl alcohol, or butanol; 45% water; and 5% concentrated ammonia) may be preferred because of the low miscibility of isocyanates with water. /Isocyanates/

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. The completeness of the cleaning procedures should be considered before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at the end of shift, but should remain at employee's place of work for cleaning.

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

The open points at the interface between different forms of protective clothing, e.g., the opening that forms between the sleeve of a protective suit and a glove, should be sealed to prevent exposure through the interface. A common and effective method for sealing these interfaces is to use duct tape to join the two different forms of protective clothing. /Isocyanate-containing substances/

NIOSH recommends that employers provide workers with appropriate training on the inhalation and dermal exposure hazards associated with isocyanate-containing materials and on the proper use of personal protective equipment (PPE) associated with protection from these exposures. /Isocyanate-containing substances/

NIOSH recommends that empoloyers conduct industrial hygiene (IH) surveys on all workers potentially exposed to isocyanates. /Isocyanates/

Excerpt from ERG Guide 156 [Substances - Toxic and/or Corrosive (Combustible / Water-Sensitive)]:

NIOSH investigators recommend that dermal exposures to isocyanate-containing substances be prevented. Employers should provide protective clothing, gloves, and footwear that is impervious to isocyanate--containing compounds. The protective clothing should either be disposed or laundered after each use (e.g., at the end of the work shift). The gloves should be elbow-length and made of an isocyanate-resistant material. /Isocyanate-containing substances/

Face-shields and aprons should be used whenever there is a possibility of a splash or a spill of liquids containing isocyanate-containing materials. /Isocyanate-containing substances/

TERRESTRIAL FATE: Isocyanates hydrolyze readily(1), suggesting that adsorption of 4-chlorophenyl isocyanate is not expected to be an important fate process in moist soil(SRC). 4-Chlorophenyl isocyanate is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 0.194 mm Hg at 25 °C(4). Biodegradation data in soil were not available(SRC, 2012).

AQUATIC FATE: Isocyanates hydrolyze rapidly(1), indicating that adsorption to sediments, volatilization from water and moist soil and bioconcentration of 4-chlorophenyl isocyanate are not expected to be important environmental fate processes(SRC). Biodegradation data in water were not available(SRC, 2012).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 4-chlorophenyl isocyanate, which has a vapor pressure of 0.194 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 4-chlorophenyl isocyanate 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 7 days(SRC), calculated from its rate constant of 1.5X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). 4-Chlorophenyl isocyanate does not contain chromophores that absorb at wavelengths >290 nm(4), and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

IDENTIFICATION AND USE: 4-Chlorophenyl isocyanate is colorless to slightly yellow liquid or crystals. It can also exist as a white solid or crystalline material. It is soluble in water and organic solvents. It is used as a chemical intermediate for pharmaceuticals, herbicides and pesticides. HUMAN EXPOSURE AND TOXICITY: Acute effects include airway irritation, cough, dyspnea, asthma, sensitization, and reduced pulmonary function. Occupational asthma was detected in workers exposed to isocyanates. Isocyanates may cause dermatitis when contacting the skin and vapors are highly irritating to the mucous membranes of the eyes nose and throat. Exposure to isocyanates may produce gastrointestinal symptoms. Occupational exposure may occur through inhalation of dust and dermal contact.

/HUMAN EXPOSURE STUDIES/ Sera of six workers with conclusive evidence for IgE-mediated sensitization to isocyanates were used for evaluation of immunologic cross-reactivities among eight different isocyanate-protein conjugates. In all cases RAST and/or skin-test investigations revealed the presence of IgE antibodies reacting specifically with HSA conjugated with those isocyanates to which workers were exposed as well as with other isocyanates with which they had not been in contact. By the RAST inhibition technique, moderate to strong mutual cross-reactivities between all tested isocyanate-HSA conjugates--even between aromatic and aliphatic ones--could be demonstrated in tests with five sera. The magnitudes of cross-reactivities differed, however, from one patient to another. One serum contained IgE antibodies that were almost completely specific to TDI-HSA; with this serum only weak cross-reactivities with other isocyanate conjugates could be demonstrated. These results indicate the predominance of closely related antigenic determinants in HSA conjugated with different isocyanates. The common antibody-binding regions are obviously recognized to different extents by antibodies of clinically sensitized workers, indicating individual differences in specificities and avidities of antibody populations. Nearly complete lack of IgE binding of ovalbumin-bound TDI in RAST and RAST inhibition indicates carrier-specific antigenicity of isocyanate-protein conjugates. In addition, since unmodified HSA did not bind IgE, antigenic determinants of the conjugates studied should be predominantly formed by the isocyanate-protein bond regions and concurrently by neighboring amino acid residues of the HSA molecule. /Isocyanates/

/SIGNS AND SYMPTOMS/ ISOCYANATES MAY CAUSE DERMATITIS WHEN CONTACTING SKIN & VAPORS ARE HIGHLY IRRITATING TO MUCOUS MEMBRANES OF EYES, NOSE, & THROAT, & TO LUNGS. /ISOCYANATES/

/SIGNS AND SYMPTOMS/ Strong mucous membrane irritation causes eye, pulmonary, and gastrointestinal tract symptoms. These compounds are potent pulmonary sensitizers which cause bronchospasm, even in patients without prior airway hyperreactivity. Diisocyanate compounds act either as inducers of nonspecific bronchial hyperreactivity or as direct pharmacologic agonists. Isocyanates apparently have the potential to sensitize certain segments of the population. Elevated humoral antibodies (ie, specific IgE antibodies to the p-tolyl determinant but not the diisocyanate conjugate) were detected in sensitized workers, but cell-mediated immunity also may produce hypersensitivity reactions. In the absence of renewed exposure, radioallergosorbent titers may not distinguish sensitive from nonsensitized workers. At high doses, toluene diisocyanate may act directly on bronchial mucosa by interfering with cholinergic and adrenergic mechanisms. /Isocyanates/

/SIGNS AND SYMPTOMS/ Exposure to isocyanates is irritating to the skin, mucous membranes, eyes, and respiratory tract. The most common adverse health outcome associated with isocyanate exposure is asthma due to sensitization; less prevalent are contact dermatitis (both irritant and allergic forms) and hypersensitivity pneumonitis (HP). Contact dermatitis can result in symptoms such as rash, itching, hives, and swelling of the extremities. /Isocyanates/

For more Human Toxicity Excerpts (Complete) data for 4-Chlorophenyl Isocyanate (9 total), please visit the HSDB record page.

4-Chlorophenyl isocyanate's production and use as a chemical intermediate for pharmaceuticals, herbicides, and pesticides(1) may result in its release to the environment through various waste streams(SRC). The compound is a photodecomposition product of the herbicide, monuron(2).

Isocyanates hydrolyze readily in water(1). Therefore, adsorption to sediments and volatilization of 4-chlorophenyl isocyanate from water and moist soil are not expected to be an important environmental fate process(SRC). 4-Chlorophenyl isocyanate is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 0.194 mm Hg(2).

The rate constant for the vapor-phase reaction of 4-chlorophenyl isocyanate with photochemically-produced hydroxyl radicals has been estimated as 1/5X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 7 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 4-Chlorophenyl isocyanate does not contain chromophores that absorb at wavelengths >290 nm(2), and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

Isocyanates hydrolyze readily in water to yield a carbamic acid, which decarboxylates to produce CO2 and an amine; the latter immediately reacts with more isocyanate to yield a disubstituted urea(1). /Isocyanates/

4-Chlorophenyl isocyanate's production and use as a chemical intermediate may result in its release to the environment through various waste streams. The compound is a photodecomposition product of the herbicide, monuron. If released to air, a vapor pressure of 0.194 mm Hg at 25 °C indicates 4-chlorophenyl isocyanate will exist solely as a vapor in the atmosphere. Vapor-phase 4-chlorophenyl isocyanate 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 7 days. 4-Chlorophenyl isocyanate does not contain chromophores that absorb at wavelengths >290 nm, and therefore is not expected to be susceptible to direct photolysis by sunlight. If released to moist soil, 4-chlorophenyl isocyanate is not expected to leach or adsorb to solids nor volatilize due to its rapid degradation reaction with water. 4-Chlorophenyl isocyanate may volatilize from dry soil surfaces based upon its vapor pressure. Biodegradation data in soil or water were not available. If released into water, 4-chlorophenyl isocyanate is not expected to adsorb to suspended solids and sediment based upon its rapid reaction with water. Volatilization from water surfaces and bioconcentration are not expected to be an important fate process based upon the rapid hydrolysis. Hydrolysis is an important environmental fate process since iocyanates hydrolyze readily in water to yield a carbamic acid. Occupational exposure to 4-chlorophenyl isocyanate may occur through inhalation of dust and dermal contact with this compound at workplaces where 4-chlorophenyl isocyanate is produced or used. (SRC)

/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/

/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/

/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/

Section 8(a) of TSCA requires manufacturers of this chemical substance to report preliminary assessment information concerned with production, exposure, and use to EPA as cited in the preamble in 51 FR 41329. Effective date: 10/29/90; Reporting date: 12/27/90.

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Benzene, 1-chloro-4-isocyanato- is included on this list. Effective date: 10/29/90; Sunset date: 6/30/98.

Used to produce pharmaceuticals and pesticides; [Hawley]

Chemical intermediate for pharmaceuticals, herbicides, and pesticides.

(1972) PROBABLY GREATER THAN 4.54X10+5 GRAMS

(1975) PROBABLY GREATER THAN 4.54X10+5 GRAMS

Production volumes for non-confidential chemicals reported under the Inventory Update Rule. [Table#3106]

Benzene, 1-chloro-4-isocyanato-: ACTIVE

PHOTOPRODUCTS OBTAINED FROM IRRIDATION OF 1-(4-CHLOROPHENYL)-3-2,6-DICHLOROBENZOYL)UREA & 1-(4-CHLOROPHENYL)-3-(2,6-DIFLUOROBENZYL)UREA IN METHANOL WAS IDENTIFIED AS PARA-CHLOROPHENYL ISOCYANATE.