Bromochloromethane

Description

Chlorobromomethane is a clear, colorless topale yellow liquid with a chloroform-like odor. Odor threshold=400 ppm. Molecular weight=129.39; Specific gravity (H2O:1)=1.93; Boiling point=68.3℃; Freezing/Melting point=2 88℃; Vapor pressure=115 mmHg at20℃. Hazard Identification (based on NFPA 704 M RatingSystem): Health 2, Flammability 0, Reactivity 0. Insolublein water.

Chemical properties

white to light yellow crystal powder

Chemical properties

Chlorobromomethane is a clear, colorless, to pale-yellow liquid with a chloroform-like odor

Physical properties

Clear, colorless liquid with a sweet, chloroform-like odor

The Uses of Bromochloromethane

Bromochloromethane is used primarily as an extinguishing agent due to its oxygen-depleting properties.

The Uses of Bromochloromethane

Fire fighting agent

Definition

ChEBI: A one-carbon compound substituted by a chloro and a bromo group.

General Description

A clear colorless liquid with a sweet chloroform-like odor. Denser than water (density 1.991 g / cm3) and insoluble in water. Hence sinks in water. Boiling point 68°C. Vapors may cause illness if inhaled. Nonflammable. When exposed to high temperatures may emit toxic fumes. Used as a fire extinguishing agent.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

Bromochloromethane is sensitive to light (may discolor). Incompatible with strong bases and strong oxidizing agents. Also incompatible with active metals, calcium, aluminum, magnesium, zinc and their alloys. Attacks some forms of plastics, rubber and coatings. .

Hazard

By inhalation.

Health Hazard

Toxic by ingestion. Vapors may cause dizziness or suffocation. Exposure in an enclosed area may be very harmful. Contact may irritate or burn skin and eyes. Fire may produce irritating and/or toxic gases. Runoff from fire control or dilution water may cause pollution.

Fire Hazard

Some of these materials may burn, but none ignite readily. Most vapors are heavier than air. Air/vapor mixtures may explode when ignited. Container may explode in heat of fire.

Safety Profile

Mildly toxic by ingestion and inhalation. Mutation data reported. This material has a narcotic action of moderate intensity, although of prolonged duration. Animals exposed for several weeks to 1000 pprn had blood bromide levels as high as 350 mgl100 g. Therefore, until further data are available, it should be considered at least as toxic as carbon tetrachloride and more than minimal exposure to its vapors should be avoided. Dangerous; when heated to decomposition it emits highly toxic fumes of Brand Cl-. See also BROMIDES and CHLORINATED HYDROCARBONS, ALIPHATIC.

Potential Exposure

This compound is used in brominated flame retardants; a fire-extinguishing agent; and in organic synthesis

First aid

If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin,remove contaminated clothing and wash immediately withsoap and water. Seek medical attention immediately. If thischemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, includingresuscitation mask) if breathing has stopped and CPR if heartaction has stopped. Transfer promptly to a medical facility.When this chemical has been swallowed, get medical attention. Give large quantities of water and induce vomiting. Donot make an unconscious person vomit. Medical observationis recommended for 24-48 h after breathing overexposure,as pulmonary edema may be delayed. As first aid for pulmonary edema, a doctor or authorized paramedic may consideradministering a corticosteroid spray.

Carcinogenicity

The U.S. EPA classification is D (not classifiable as to human carcinogenicity). Bromochloromethane is structurally similar to dichloromethane (methylene chloride), which is classified B2 (probable human carcinogen). The classification is based on the lack of data regarding the carcinogenicity of bromochloromethane in humans or animals; however, there are data indicative of genotoxic effects and structural relationships to halogenated methanes classified as B2 (probable human carcinogens).

Source

No MCLGs or MCLs have been proposed, however, a DWEL of 0.5 mg/L was recommended (U.S. EPA, 2000).
Naturally formed by algal biological processes (Orkin et al., 1997) and is a disinfection byproduct in public water treatment systems.

Environmental Fate

Biological. When bromochloromethane (5 and 10 mg/L) was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum for 7 d, 100% biodegradation with rapid adaptation was observed (Tabak et al., 1981).
Photolytic. The following rate constants were reported for the reaction of bromochloromethane and OH radicals as measured by both flash photolysis resonance fluorescence and discharge flow electron paramagnetic resonance techniques (x 10^-13 cm³/molecule?sec): 0.91 at 4 °C, 1.11–1.13 at 25 °C, 1.32–1.34 at 40 °C, 1.55–1.58 at 57 °C, 1.76–1.90 at 76 °C, 2.10–2.26 at 97 °C (Orkin et al., 1997).
Chemical/Physical. Although no products were identified, the estimated hydrolysis half-life in water at 25 °C and pH 7 is 44 yr (Mabey and Mill, 1978). Bromochloromethane reacts with bisulfide ion (HS-), produced by microbial reduction of sulfate, forming 1,3,5-trithiane and dithiomethane. Estimated reaction rate constants at 25 and 35 °C were 7.29 x 10^-5 and 2.42 x 10- 4/M?sec, respectively (Roberts et al., 1992).

storage

Color Code—Blue: Health Hazard/Poison: Storein a secure poison location. Prior to working with thischemical you should be trained on its proper handling andstorage. Chlorobromomethane must be stored to avoid contact with chemically active metals, since violent reactionsoccur. Store in tightly closed containers in a cool, wellventilated area away from heat.

Shipping

UN1887 Bromochloromethane, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.

Incompatibilities

Incompatible with strong oxidizers (possible explosion), reducing agents, bases, carbonates, furyl alcohol, chemically active metals, such as calcium; base metals in the presence of moisture, powdered aluminum; zinc, magnesium. Liquid attacks some plastics, rubber, and coatings.

Waste Disposal

Incinerate together with flammable solvent in furnace equipped with afterburner and alkali scrubber.