Bromochloromethane

log Kow = 1.41

1.41

2100 mg/cu m (odor threshold low); 2100 mg/cu m (odor threshold high) sweet.

Chloroform-like odor

1.93 at 77 °F (NTP, 1992) - Denser than water; will sink

1.9344 g/cu cm at 20 °C

Density of saturated air: 1.72 (Air = 1)

Relative density (water = 1): 2.0

1.93

1.93 @ 20°C

0.670 mN.s/sq m at 20 °C

0.33 mm²/s at 20 °C

Clear, colorless liquid

Colorless to pale-yellow liquid

1 to 5 mg/mL at 68 °F (NTP, 1992)

In water, 1.67X10+4 mg/L at 25 °C

0.9 part in 100 parts water

Insoluble in water

Completely miscible with common organic solvents

For more Solubility (Complete) data for Bromochloromethane (8 total), please visit the HSDB record page.

This chemical does not meet GHS hazard criteria for 1.1% (1 of 92) of reports.

Danger

H314 (47.8%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

P260, P261, P264, P264+P265, P271, P280, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P319, P321, P332+P317, P362+P364, P363, P403+P233, P405, P501, and P502 (click each P-code to see the statement)

Aggregated GHS information provided per 92 reports by companies from 12 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Danger

Chemical: Methane, bromochloro-

Methane, bromochloro- is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Methane, bromochloro- are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

TP - indicates a substance that is the subject of a proposed TSCA section 4 test rule.

Status: Active Update: 19-12-2014 https://echa.europa.eu/registration-dossier/-/registered-dossier/7281

Bromochloromethane: Does not have an individual approval but may be used under an appropriate group standard

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

Excerpt from ERG Guide 160 [Halogenated Solvents]:

· Some of these materials may burn, but none ignite readily.

Not combustible. Gives off irritating or toxic fumes (or gases) in a fire. Heating will cause rise in pressure with risk of bursting.

Excerpt from ERG Guide 160 [Halogenated Solvents]:

· Toxic by ingestion.

1887 160

1887 160

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. Methane, bromochloro- is included on this list. Effective date: 6/1/87; Sunset date: 12/19/95.

Excerpt from ERG Guide 160 [Halogenated Solvents]:

In case of fire in the surroundings, use appropriate extinguishing media. In case of fire: keep drums, etc., cool by spraying with water.

Fresh air, rest. Half-upright position. Administration of oxygen may be needed. Artificial respiration may be needed. Refer for medical attention.

Remove contaminated clothes. Rinse and then wash skin with water and soap. Refer for medical attention .

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

Rinse mouth. Do NOT induce vomiting. Give one or two glasses of water to drink. Refer for medical attention .

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

General First Aid:

(General first aid procedures)

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.

Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.

If material involved in fire: Cool all affected containers with flooding quantities of water. Use water in flooding quantities as fog. Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Apply water from as far a distance as possible. Keep run off water out of sewers and water sources.

Personnel protection: ... Wear positive pressure self-contained breathing apparatus when fighting fires involving this material.

For more Fire Fighting Procedures (Complete) data for Bromochloromethane (6 total), please visit the HSDB record page.

Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Light sensitive. Storage class (TRGS 510): Non-combustible, acute toxic Cat.3 / toxic hazardous materials or hazardous materials causing chronic effects

Store in a secure poison location. ... Chlorobromomethane must be stored to avoid contact with chemically active metals, since violent reactions occur. Store in tightly closed containers in a cool, well-ventilated area away from heat.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas; Environmental precautions: Do not let product enter drains; Methods and materials for containment and cleaning up: Soak up with inert absorbent material and dispose of as hazardous waste. Keep in suitable, closed containers for disposal.

1. Ventilate area of spill or leak. 2. Collect for reclamation or absorb in vermiculite, dry sand, earth, or similar material.

Evacuate and restrict persons not wearing protective equipment from area of spill or leak until cleanup is complete. Remove all ignition sources. Ventilate area of spill or leak. Absorb liquids in vermiculite, dry sand, earth, peat, carbon, or a similar material and deposit in sealed containers. It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters.

SRP: 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 air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

Product: Offer surplus and non-recyclable solutions to a licensed disposal company; Contaminated packaging: Dispose of as unused product.

Chlorobromomethane may be disposed of by absorbing it in vermiculite, dry sand, earth, or a similar material, & disposing in a secured landfill.

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

For more Disposal Methods (Complete) data for Bromochloromethane (6 total), please visit the HSDB record page.

Personal protection: filter respirator for organic gases and vapours adapted to the airborne concentration of the substance. Ventilation. Do NOT let this chemical enter the environment. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 22(SRC), determined from a structure estimation method(2), indicates that bromochloromethane is expected to have very high mobility in soil(SRC). Volatilization of bromochloromethane from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.46X10-3 atm-cu m/mole(SRC) based upon its vapor pressure, 142 mm Hg(3), and water solubility, 1.67X10+4 mg/L(4). Bromochloromethane is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(3). Utilizing the Japanese MITI test, 0% of the Theoretical BOD was reached in 4 weeks(5) indicating that biodegradation is not an important environmental fate process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 22(SRC), determined from a structure estimation method(2), indicates that bromochloromethane 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 1.46X10-3 atm-cu m/mole(SRC), derived from its vapor pressure, 142 mm Hg(4), and water solubility, 1.67X10+4 mg/L(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 4 hrs and 5 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 4(SRC), from its log Kow of 1.41(7) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Utilizing the Japanese MITI test, 0% of the Theoretical BOD was reached in 4 weeks(8) indicating that biodegradation is not an important environmental fate process in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), bromochloromethane, which has a estimated vapor pressure of 142 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase bromochloromethane 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 108 days(SRC), calculated from its rate constant of 8.80X10-14 cu cm/molecule-sec at 25 °C(3). The atmospheric lifetime is further reduced by ocean removal(4). On the basis of its water solubility and assuming that dissolution in the ocean leads to chemical degradation, the atmospheric lifetime will be reduced by approximately a factor of 2(4). Bromochloromethane does not absorb light at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

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

inhalation, ingestion, skin and/or eye contact

IDENTIFICATION AND USE: Chlorobromomethane is a colorless to pale-yellow liquid. The major use of chlorobromomethane is as fire-extinguishing fluid, particularly for aircraft and portable systems. It is also used as an explosion suppression agent, as a solvent, and as an intermediate in the manufacture of some insecticides (chlormephos). HUMAN EXPOSURE AND TOXICITY: Symptoms of exposure to chlorobromomethane include disorientation; dizziness; irritation of the skin, eyes and throat; pulmonary edema; headache; anorexia; nausea; vomiting; abdominal pain; weight loss; memory impairment; paralysis; weakness; tremors; convulsions; and CNS depression. It may cause coughing, chest pain, and difficulty in breathing. It may also cause transient corneal epithelium damage. The compound is extremely destructive to tissue of the mucous membranes, upper respiratory tract, eyes, and skin. One firefighter's cornea was injured when a fire extinguisher containing chlorobromomethane and dichlorodifluoromethane was discharged close to his face. Soon thereafter partial loss of corneal epithelium was observed, but deeper layers of cornea remained clear. ANIMAL STUDIES: Exposure of rabbit eyes to a spray of liquid from fire extinguisher containing a mixture of 75% chlorobromomethane plus 25% dichlorodifluoromethane caused transient corneal epithelial injury and conjunctival edema. When applied repeatedly to open skin of rabbits, chlorobromomethane resulted in some hyperemia and exfoliation. When bandaged on, it produced moderate irritation and hyperemia. Concentrations as low as 3000 ppm produced light narcosis in rats. Transient pulmonary edema was observed at concentrations below 27,000 ppm. At higher concentrations, interstitial pneumonitis resulted in delayed deaths. Delayed deaths were also observed after exposure to 20,000 ppm. Deaths during exposure occurred only from exposures above 27,000 ppm. In dogs, acute exposures to high concentrations produced agitation, cardiac arrhythmias, myocardial sensitization to epinephrine, and epileptiform convulsions within 12 min. Chlorobromomethane was mutagenic toward Salmonella typhimurium strains TA100 and TA1535 which contains rat glutathione S-transferase 5-5. Reverse mutations were observed at the tyr locus in Escherichia coli WU361089 exposed at 10 uL/plate without activation. Prophage induction was also observed in E. coli K394 exposed without activation at 10 uL/plate. In an in vitro test with FAF-cells of Chinese hamsters, the compound produced an increase of the sister chromatid exchange frequency.

Sore throat. Cough. Nausea. Headache. Shortness of breath. Dizziness. Drowsiness. Unconsciousness.

Dry skin. Redness.

Redness. Pain.

Abdominal pain. Further see Inhalation.

irritation eyes, skin, throat; confusion, dizziness, central nervous system depression; pulmonary edema

EPA has released the Interactive Chemical Safety for Sustainability (iCSS) Dashboard. The iCSS Dashboard provides an interactive tool to explore rapid, automated (or in vitro high-throughput) chemical screening data generated by the Toxicity Forecaster (ToxCast) project and the federal Toxicity Testing in the 21st century (Tox21) collaboration. /The title compound was tested by ToxCast and/or Tox21 assays/[USEPA; ICSS Dashboard Application; Available from, as of December 17, 2015: http://actor.epa.gov/dashboard/]

The following medical procedures should be made available to each employee who is exposed to chlorobromomethane at potentially hazardous levels: Initial Medical Screening: Employees should be screened for history of certain medical conditions (listed below) which might place the employee at increased risk from chlorobromomethane. Skin disease: Chlorobromomethane can cause dermatitis on prolonged exposure. Persons with existing skin disorders may be more susceptible to effects of this agent. Liver disease: Although chlorobromomethane is not known as a liver toxin in humans, the importance of this organ in the biotransformation and detoxification of foreign substances should be considered before exposing persons with impaired liver function. Kidney disease: Although chlorobromomethane is not known as a kidney toxin in humans, the importance of this organ in the elimination of toxic substances justifies special consideration in those with impaired renal function. Chronic respiratory disease: In persons with impaired pulmonary function, especially those with obstructive airway disease, the breathing of chlorobromomethane might cause exacerbation of symptoms due to its irritant properties. 2. Periodic medical exam: Any employee developing the above listed conditions should be referred for further medical examination.

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. Methane, bromochloro- is included on this list. Effective date: 6/1/87; Sunset date: 12/19/95.

(ME) MAINE 10 ug/L

(FL) FLORIDA 90 ug/L

Protein synthesis and lipid peroxidation were evaluated in rat liver slices incubated in the presence of oxidants and protein synthesis inhibitors. Protein synthesis by rat liver slices was evaluated by [3H]leucine incorporation into the trichloroacetic acid (TCA)-insoluble material, and lipid peroxidation was evaluated by thiobarbituric acid-reactive substances (TBARS) released into the incubation medium. Protein synthesis inhibition by bromotrichloromethane (BrCCl3) or t-butyl hydroperoxide (t-BOOH) depended on the incubation time and oxidant concentration. [(3)H]Leucine incorporation was decreased to 20 and 47% of control values and TBARS were enhanced from the control value of 16.9 to 45.3 and 62.5 nmol/g of liver by incubation for 1 hr with 1 mM BrCCl3 and t-BOOH, respectively. Following incubation, both protein synthesis damage and lipid peroxidation were decreased in control and oxidant-treated slices prepared from rats injected with 200 mg of DL-alpha-tocopherol/kg of body wt. Release of lactate dehydrogenase was not enhanced by oxidant treatment. Protein synthesis inhibitors reversibly decreased [(3)H]leucine incorporation, but the effect of oxidants on protein synthesis was irreversible. Cumene hydroperoxide and methyl ethyl ketone peroxide, but not hydrogen peroxide, damaged protein synthesis and induced lipid peroxidation. The ability of carbon tetrabromide, benzyl chloride, bromoform, bromobenzene, carbon tetrachloride, chloroform, dichloromethane, and bromochloromethane to inhibit protein synthesis was correlated with their ability to induce lipid peroxidation, and with their LD50. The results suggest that oxidant-induced lipid peroxidation and protein synthesis damage occurred concurrently, and that protein synthesis inhibition may be involved in cell injury or death mediated by free radicals.

... Inorganic bromide in blood serum and urine /was determined/ in dogs exposed to 1000 ppm of methylene chlorobromide in air. These animals were exposed 7 hr/day, 5 days/week. During the third week, the serum inorganic bromide had increased from a normal of 5 to 10 mg/100 mL to >200 mg. By the 13th and 14th weeks, the concentration was greater than 300 mg of inorganic bromide per 100 mL of blood. ... The ... concentration of volatile bromide /was determined/ expressed as milligrams of methylene chlorobromide per 100 mL of blood. Taken immediately at the end of the exposure, concentrations between 5 and 9 mg of methylene chlorobromide per 100 mL were observed. At periods of 17-65 hr after the end of the last exposure, no volatile bromide was observed in one dog and concentrations of <1 mg in the other. It would appear that methylene chlorobromide as such appears in the blood during exposure to vapors in air, but disappears rapidly on cessation of exposure. Apparently, a significant amount of material is hydrolyzed or metabolized to yield inorganic bromide ... .

Dichloromethane (methylene chloride, DCM) and other dihalomethanes are metabolized to carbon monoxide (CO) which reversibly binds hemoglobin and is eliminated by exhalation. We have developed a physiologically based pharmacokinetic (PB-PK) model which describes the kinetics of CO, carboxyhemoglobin (HbCO), and parent dihalomethane, and have applied this model to examine the inhalation kinetics of CO and of DCM in rats and humans. The portion of the model describing CO and HbCO kinetics was adapted from the Coburn-Forster-Kane equation, after modification to include production of CO by DCM oxidation. DCM kinetics and metabolism were described by a generic PB-PK model for volatile chemicals ... Physiological and biochemical constants for CO were first estimated by exposing rats to 200 ppm CO for 2 hr and examining the time course of HbCO after cessation of CO exposure. These CO inhalation studies provided estimates of CO diffusing capacity under free breathing and for the Haldane coefficient, the relative equilibrium distribution ratio for hemoglobin between CO and O2. The CO model was then coupled to a PB-PK model for DCM to predict HbCO time course behavior during and after DCM exposures in rats. By coupling the models it was possible to estimate the yield of CO from oxidation of DCM. In rats only about 0.7 mol of CO are produced from 1 mol of DCM during oxidation. The combined model adequately represented HbCO and DCM behavior following 4-hr exposures to 200 or 1000 ppm DCM, and HbCO behavior following 1/2-hr exposure to 5160 ppm DCM or 5000 ppm bromochloromethane. The rat PB-PK model was scaled to predict DCM, HbCO, and CO kinetics in humans exposed either to DCM or to CO. Three human data sets from the literature were examined: (1) inhalation of CO at 50, 100, 250, and 500 ppm; (2) seven 1/2-hr inhalation exposures to 50, 100, 250, and 500 ppm DCM; and (3) 2-hr inhalation exposures to 986 ppm DCM. An additional data set from human volunteers exposed to 100 or 350 ppm DCM for 6 hr is reported here for the first time. Endogenous CO production rates and the initial amount of CO in the blood compartment were varied in each study as necessary to give the baseline HbCO value, which varied from less than 0.5% to greater than 2% HbCO. The combined PB-PK model gave a good representation of the observed behavior in all four human studies.

In vivo metabolic constants were determined in male Fischer rats for five chemicals: 1,1-dichloroethylene (1,1-DCE), diethyl ether (DE), bromochloromethane (BCM), methyl chloroform (MC), and carbon tetrachloride (CCl4). A closed recirculated exposure system was used to collect a series of uptake curves for each chemical at a range of initial concentrations. The shapes of these curves were a function of the tissue partition coefficients and the kinetic characteristics of the metabolism of these chemicals. Tissue:air partition coefficients were experimentally determined for each chemical and incorporated into a physiological kinetic model which was then used to simulate the uptake process. An optimal fit of the family of uptake curves for each chemical was obtained by adjusting the biochemical constants for metabolism of the chemical. Metabolism of both 1,1-DCE and CCl4 was represented by a single saturable process while MC required only a first-order pathway. BCM and DE exhibited a combination of both a saturable and a first-order process. Pyrazole, which blocks oxidative microsomal metabolism, inhibited the saturable pathways of 1,1-DCE, BCM, DE, and CCl4 metabolism and abolished the first-order pathway for MC. The maximum velocity of metabolism for the saturable pathway with 1,1-DCE, BCM, DE, and CCl4 for a 225-g rat was 27.2, 19.9, 26.1, and 0.92 mol/hr, respectively. The simulation approach for analyzing gas uptake data distinguishes between single and multiple metabolic pathways and provides kinetic constants that can be used in predictive toxicokinetic models for describing constant concentration inhalation exposure as well as exposures by other routes of administration.

An oral dose of 6.2 mmoles of diachloromethane (DCM), bromochloromethane (BCM) or dibromomethane (DBM) per kg body mass yielded a maximum carboxyhemoglobin (COHb) level of about 9% (at 6 hr), 11% (at 8 hr) and 22% (at 12 hr), respectively. Pretreatment of rats with isoniazid, 4 x 0.36 mmol/kg i.p., produced significant enhancements of the COHb formation; the values were 18.0 +/- 0.8% COHb after DCM, 24.1 +/- 0.8% COHb after BCM, and 39.0 +/- 1.3% COHb after DBM. Prior administration of phenobarbital, 4 x 0.31 mmol/kg i.p., caused no appreciable alterations in the COHb levels after DCM and slight but significant increases after BCM as well as after DBM. The data indicate that the oxidative metabolism of dihalomethanes to carbon monoxide is mainly catalyzed by cytochrome P-450 IIE1 and that the DCM-evoked COHb formation seems to be a method of testing whether a chemical is an inducer of this form of cytochrome P-450 in vivo.

Quantification of dermal absorption of volatile organic chemicals (VOCs) from aqueous solutions is required to understand the potential health hazards resulting from skin exposure to these chemicals in contaminated water. Male Fischer 344 rats were dermally exposed (3.1-sq cm dorsal skin) to neat, one-third saturated, two-thirds saturated, or saturated aqueous solutions of 14 VOCs for 24 hr. Blood samples were obtained via indwelling jugular catheters during exposure (0, 0.5, 1, 2, 4, 8, 12, and 24 hr), and analyzed for the VOCs by gas chromatography using headspace analysis. Absorption of the neat VOCs in this series of chemicals decreased as water solubility decreased. Peak blood levels of VOCs attained during exposure for 24 hr to neat chemicals were: 1,2-dichloroethane (135.1 ug/mL), bromochloromethane (113.3 ug/mL), chloroform (51.0 ug/mL), benzene (24.2 ug/mL), tetrachloroethylene (21.1 ug/mL), dibromomethane (18.2 ug/mL), trichloroethylene (11.6 ug/mL), toluene (9.5 ug/mL), xylene (8.8 ug/mL), hexane (8.0 ug/mL), ethylbenzene (5.6 ug/mL), styrene (5.3 ug/mL), carbon tetrachloride (5.0 ug/mL), and 1,1,1-trichloroethane (3.4 ug/mL). Blood levels of 1,2-dichloroethane and benzene continued to increase during the 24-hr exposure to neat chemical, while blood levels of the other neat VOCs peaked within 4 hr and then either decreased or remained about the same for the duration of the exposure. Absorption of VOCs from one-third, two-thirds, or saturated aqueous solutions was rapid, and resulted in depletion of the chemical from the solution although only a small amount of water was absorbed. Blood levels of each VOC were directly related to the exposure concentrations. The rapid appearance of VOCs in the blood from aqueous solutions demonstrates that detectable amounts of VOCs were absorbed during exposure of only about 1% of the skin surface area of the rat.

Absorption of chemical vapors through the skin is a passive process that is not easily quantitated, but may be important in the assessment of health hazards in some occupational circumstances. Physiological modeling is a quantitative technique which may provide insight into the system being modeled and can be used for interspecies extrapolation. We developed a physiological model for the penetration of organic vapors through skin in vivo which allows the prediction of blood concentrations, after dermal vapor exposures in the rat, when chemical distribution coefficients, physiological and metabolic parameters, and skin permeability constants are known. We used the model in two distinct ways. First, permeability constants for dibromomethane (DBM), bromochloromethane (BCM), and methylene chloride (DCM) were calculated by using a physiologically based pharmacokinetic model for dihalomethanes to relate blood concentrations during dermal vapor exposures to the total amount of chemical which was absorbed through the skin. Second, a skin compartment was added to the model which had input based on the permeability-area-concentration product. This predictive model adequately described blood concentrations after DBM, BCM, and DCM dermal vapor exposures over a wide range of concentrations. This model could easily be modified for use with other organic vapors, and could be used to extrapolate to human vapor exposure conditions by substituting human physiological parameters for the animal values, providing permeability constants are known or can be determined.

The dermal absorption of dibromomethane (DBM) and bromochloromethane (BCM) vapors was studied in rats placed in a specially designed chamber incorporating individual respiratory protection to avoid pulmonary uptake. Exposures (DBM: 500 to 10,000 ppm; BCM: 2500 to 40,000 ppm) lasted 4 hr during which time five blood samples were drawn from jugular cannulae for analysis of the parent dihalomethane by gas chromatography. Estimates of the amounts of chemicals stored in tissues and exhaled were based on concentrations in the blood and tissue partition coefficients, tissue volumes, and ventilation rate. Total metabolism was estimated from the amount of bromide released during the 4-hr exposure. The total amount of vapor absorbed through the skin was calculated from the estimates of the amount of parent chemical in blood and tissues, and the amounts exhaled and metabolized. The dermal flux for each concentration (DBM: 0.004 to 0.078 mg/sq cm/hr; BCM: 0.011 to 0.164 mg/sq cm/hr) was calculated by dividing the amount absorbed by exposed surface area and duration of exposure. Flux was divided by exposure concentration to calculate a permeability constant. With each dihalomethane the permeability constants (DBM: congruent to 1.12 cm/hr; BCM: congruent to 0.79 cm/hr) were essentially independent of exposure concentration. This study shows that a whole-body dermal vapor exposure in rodents is technically possible, and quantitation of penetration can be accomplished using calculations based on achieved blood concentrations and some measure of metabolism.

Bromochloromethane (BCM) is a volatile compound and a by-product of disinfection of water by chlorination. Physiologically based pharmacokinetic (PBPK) models are used in risk assessment applications. An updated PBPK model for BCM is generated and applied to hypotheses testing calibrated using vapor uptake data. The two different metabolic hypotheses examined are (1) a two-pathway model using both CYP2E1 and glutathione transferase enzymes and (2) a two-binding site model where metabolism can occur on one enzyme, CYP2E1. Our computer simulations show that both hypotheses describe the experimental data in a similar manner. The two pathway results were comparable to previously reported values (V(max)=3.8 mg/hr, K(m)=0.35 mg/L, and k(GST)=4.7 /hr). The two binding site results were V(max(1))=3.7 mg/hr, K(m(1))=0.3 mg/hr, CL(2)=0.047 L/hr. In addition, we explore the sensitivity of different parameters for each model using our obtained optimized values.

For more Absorption, Distribution and Excretion (Complete) data for Bromochloromethane (6 total), please visit the HSDB record page.

Used in fire extinguishers; [ACGIH]

See CHLOROFLUOROCARBONS

The major use of bromochloromethane is as fire-extinguishing fluid; its effectiveness per unit weight makes it suitable for use in aircraft and portable systems. It is also used as an explosion suppression agent, as a solvent, and as an intermediate in the manufacture of some insecticides (chlormephos).

Both dibromomethane and bromochloromethane (or mixtures of these two compounds) are used as solvents for bromination reactions, especially for the production of polybrominated aromatic compounds and polymers.

Organic synthesis.

2023: 1,000,000 - <8,500,000 lb

(1972) PROBABLY GREATER THAN 4.54X10+5 G

(1975) PROBABLY GREATER THAN 4.54X10+5 G

Non-confidential 2012 Chemical Data Reporting (CDR) information on the production and use of chemicals manufactured or imported into the United States. Chemical: Methane, bromochloro-. National Production Volume: Withheld.

Common routes for its production involve the partial replacement of chlorine in dichloromethane by a halogen exchange reaction using either bromine or hydrogen bromide. Both processes are carried out in the presence of aluminum or aluminum trihalide.

Pesticide, Fertilizer, and Other Agricultural Chemical Manufacturing

Methane, bromochloro-: ACTIVE