dibromomethane

H332: Harmful if inhaled [Warning Acute toxicity, inhalation]

H412: Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P261, P271, P273, P304+P340, P317, and P501 (click each P-code to see the statement)

H301 (22.4%): Toxic if swallowed [Danger Acute toxicity, oral]

H332 (82.4%): Harmful if inhaled [Warning Acute toxicity, inhalation]

H412 (82.4%): Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

P261, P264, P270, P271, P273, P301+P316, P304+P340, P317, P321, P330, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 125 reports by companies from 9 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

H315: Causes skin irritation [Warning Skin corrosion/irritation]

H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H336: May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]

H361: Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]

H402: Harmful to aquatic life [Hazardous to the aquatic environment, acute hazard]

P203, P261, P264, P264+P265, P271, P273, P280, P302+P352, P304+P340, P305+P351+P338, P317, P318, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

P261, P271, P304+P340, P319, P403+P233, P405, and P501 (click each P-code to see the statement)

Fresh air, rest. 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.

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. Refer for medical attention .

INHALATION: Remove from exposure. Give oxygen if needed.

INGESTION: No specific antidote.

CONTACT WITH SKIN AND EYES: Remove contaminated clothing; wash skin or eyes if affected. (USCG, 1999)

General First Aid:

· Call 911 or emergency medical service.

· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.

· Move victim to fresh air if it can be done safely.

· Administer oxygen if breathing is difficult.

· If victim is not breathing:

-- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance.

-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).

-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.

· Remove and isolate contaminated clothing and shoes.

· For minor skin contact, avoid spreading material on unaffected skin.

· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.

· For severe burns, immediate medical attention is required.

· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.

· Keep victim calm and warm.

· Keep victim under observation.

· For further assistance, contact your local Poison Control Center.

· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.

Specific First Aid:

· Wash skin with soap and water.

Excerpt from ERG Guide 160 [Halogenated Solvents]:

SMALL FIRE: Dry chemical, CO2 or water spray.

LARGE FIRE: Dry chemical, CO2, alcohol-resistant foam or water spray. If it can be done safely, move undamaged containers away from the area around the fire. Dike runoff from fire control for later disposal.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. (ERG, 2024)

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

If material involved in fire: Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.) Use foam, dry chemical, or carbon dioxide.

· 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.

· Keep unauthorized personnel away.

· Stay upwind, uphill and/or upstream.

· Many gases are heavier than air and will spread along the ground and collect in low or confined areas (sewers, basements, tanks, etc.).

· Ventilate closed spaces before entering, but only if properly trained and equipped.

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

· Stop leak if you can do it without risk.

Small Liquid Spill

· Pick up with sand, earth or other non-combustible absorbent material.

Large Spill

· Dike far ahead of liquid spill for later disposal.

· Prevent entry into waterways, sewers, basements or confined areas.

Excerpt from ERG Guide 160 [Halogenated Solvents]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 50 meters (150 feet) in all directions.

LARGE SPILL: Consider initial downwind evacuation for at least 100 meters (330 feet).

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

Immediate precautionary measure

· Isolate spill or leak area for at least 50 meters (150 feet) in all directions.

· Consider initial downwind evacuation for at least 100 meters (330 feet).

· If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.

Personal protection: filter respirator for organic gases and vapours adapted to the airborne concentration of the substance. Ventilation. 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.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U068, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

A potential candidate for rotary kiln incineration at a temperature range of 820 to 1,600 °C and residence times of seconds for liquids and gases, and hours for solids. A potential candidate for fluidized bed incineration at a temperature range of 450 to 980 °C and residence times of seconds for liquids and gases, and longer for solids.

If material not on fire and not involved in fire: Build dikes to contain flow as necessary.

Personnel protection: Avoid breathing vapors. ... Avoid bodily contact with the material.

Excerpt from ERG Guide 160 [Halogenated Solvents]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Stop leak if you can do it without risk.

SMALL LIQUID SPILL: Pick up with sand, earth or other non-combustible absorbent material.

LARGE SPILL: Dike far ahead of liquid spill for later disposal. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2024)

Separated from food and feedstuffs, strong oxidants, strong bases and metals. Do NOT store or transport in containers made from aluminium or plastic. Ventilation along the floor.

... MATERIALS WHICH ARE TOXIC AS STORED OR WHICH CAN DECOMP INTO TOXIC COMPONENTS DUE TO CONTACT WITH HEAT, MOISTURE, ACID, OR ACID FUMES, SHOULD BE STORED IN COOL, WELL VENTILATED PLACE, OUT OF DIRECT RAYS OF SUN, AWAY FROM AREAS OF HIGH FIRE HAZARD & SHOULD BE PERIODICALLY INSPECTED & MONITORED.

· Wear positive pressure self-contained breathing apparatus (SCBA).

· Wear chemical protective clothing that is specifically recommended by the manufacturer when there is NO RISK OF FIRE.

· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

21 [mg/m3]

230 [mg/m3]

1400 [mg/m3]

Small Fire

· Dry chemical, CO2 or water spray.

Large Fire

· Dry chemical, CO2, alcohol-resistant foam or water spray.

· If it can be done safely, move undamaged containers away from the area around the fire.

· Dike runoff from fire control for later disposal.

Fire Involving Tanks, Rail Tank Cars or Highway Tanks

· Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles.

· Cool containers with flooding quantities of water until well after fire is out.

· Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank.

· ALWAYS stay away from tanks in direct contact with flames.

Max allowable concn (USSR) 10 mg/cu m

A harmful contamination of the air can be reached very quickly on evaporation of this substance at 20 °C.

The substance is mildly irritating to the eyes, skin and respiratory tract. If swallowed the substance may cause vomiting and could result in aspiration pneumonitis. The substance may cause effects on the central nervous system, blood and heart. Exposure could cause carbon monoxide poisoning. This may result in impaired functions. The effects may be delayed. Exposure at high concentrations could cause unconsciousness or death.

Repeated or prolonged contact with skin may cause dermatitis. The substance may have effects on the central nervous system, liver, kidneys and lungs.

Organic vapor canister mask, safely glasses, protective clothing. (USCG, 1999)

Respiratory protection: 200 ppm or less: Any supplied-air respirator. Any self contained breathing apparatus; 1000 ppm or less: Any supplied air respirator with a full facepiece, helmet, or hood. Any self contained breathing apparatus with a full facepiece; 2000 ppm or less: A Type C supplied air respirator operated in pressure demand or other positive pressure mode; Greater than 2000 ppm or entry and escape from unknown concentrations: Self contained breathing apparatus with a full facepiece operated in pressure demand or other positive pressure mode, or a combination respirator which includes a Type C supplied air respirator with a full facepiece operated in pressure demand, or other positive pressure or continuous flow mode and an auxillary self contained breathing apparatus operated in pressure demand or other positive pressure mode; Escape: Any gas mask providing protection against organic vapors, or any self contained breathing apparatus. /Methyl bromide/

Methylene bromide breakthrough times greater than one hour reported by (normally) two or more testers for polyvinyl alcohol.

See Chemical Dangers

PREVENT GENERATION OF MISTS! STRICT HYGIENE!

Use ventilation, local exhaust or breathing protection.

Protective gloves. Protective clothing.

Wear safety spectacles or eye protection in combination with breathing protection.

Do not eat, drink, or smoke during work.

Dibromomethane appears as a colorless liquid with a pleasant odor. Insoluble in water and denser than water. May be toxic by ingestion. Used as a solvent and as a motor fuel.

Colorless liquid with a sweet, pleasant odor; [CHRIS] Clear colorless liquid; [Sigma-Aldrich MSDS]

COLOURLESS LIQUID.

Clear, colorless liquid

206.6 °F at 760 mmHg (USCG, 1999)

97 °C @760 [mm Hg]

-62.5 °F (USCG, 1999)

-52.5 °C

-52.7 °C

11.70 g/1000 g water @ 15 °C; 11.93 g/1000 g water @ 30 °C

Miscible with chloroform, alcohol, ether, acetone

> 10% in acetone

> 10% in ether

For more Solubility (Complete) data for DIBROMOMETHANE (6 total), please visit the HSDB record page.

Solubility in water, g/100ml at 15 °C: 1.2 (moderate)

2.497 at 68 °F (USCG, 1999) - Denser than water; will sink

2.4969 g/cc @ 20 °C

Relative density (water = 1): 2.5

2.497 @ 20°C

6.05 (Air= 1)

Relative vapor density (air = 1): 6.0

87.89 mmHg (USCG, 1999)

44.4 [mmHg]

Vapor pressure: 40 mm Hg @ 23.3 °C

44.4 mm Hg @ 25 °C

Vapor pressure, kPa at 20 °C: 4.7

44.4 [mm Hg] @25 °C

log Kow = 1.70

1.88 (estimated)

Henry's Law constant: 8.22E-4 atm cu m/mol @ 20 °C

When heated to decomp it emits toxic fumes of /hydrogen bromide/.

1.320 mPa @ 0 °C; 0.980 mPa @ 25 °C

0.39 mm²/s at 25 °C

32.92 kJ/mol @ 97 °C; 36.97 kJ/mol @ 25 °C

Index of refraction: 1.5420 @ 20 °C/D

Enthalpy of formation: -3.53 kcal/mole; Gibbs energy of formation: -3.87 kcal/mole; entropy: 70.10 cal/deg-mole @ 298.15 K; heat capacity 13.04 cal/deg-mole

Dielectric constant: 7.7 @ 10 °C & 6.7 @ 40 °C; dipole moment: 1.43 (gas), 1.85 @ 20 °C (liq)

Hydroxyl radical rate constant =1.13X10-13 @ 25 °C

Coriolis coupling

Gibbs energy

Insoluble in water.

Halogenated Organic Compounds

Halogenated aliphatic compounds, such as DIBROMOMETHANE, are moderately or very reactive. Halogenated organics generally become less reactive as more of their hydrogen atoms are replaced with halogen atoms. Low molecular weight haloalkanes are highly flammable and can react with some metals to form dangerous products. Materials in this group are incompatible with strong oxidizing and reducing agents. Also, they are incompatible with many amines, nitrides, azo/diazo compounds, alkali metals (potassium), and epoxides.

Although apparently stable on contact, mixtures of potassium (or its alloys) with a wide range of halocarbons are shock-sensitive & may explode with great violence on light impact. Chloroethane, dichloroethane ... dibromomethane & diiodomethane are among those investigated. Sensitivity increases generally with the degree of substitution ...

Bromine is a powerful oxidizing agent and is able to release oxygen free radicals from the water in mucous membranes. These free radicals are also potent oxidizers and produce tissue damage. In additon, the formation of hydrobromic and bromic acids will result in secondary irritation. The bromide ion is also known to affect the central nervous system, causing bromism. This is believed to be a result of bromide ions substituting for chloride ions in the in actions of neurotransmitters and transport systems, thus affecting numerous synaptic processes. (L626, L627, A543)

Dibromomethane

Volatile Organic Compound (VOC) (Pesticide/Volatile Organic Compound (VOC))

Smith, C.D. and Nowell, L.H., 2024. Health-Based Screening Levels for evaluating water-quality data (3rd ed.). DOI:10.5066/F71C1TWP

No indication of carcinogenicity to humans (not listed by IARC).

Bromine vapour causes irritation and direct damage to the mucous membranes. Elemental bromine also burns the skin. The bromide ion is a central nervous system depressant and chronic exposure produces neuronal effects. This is called bromism and can result in central reactions reaching from somnolence to coma, cachexia, exicosis, loss of reflexes or pathologic reflexes, clonic seizures, tremor, ataxia, loss of neural sensitivity, paresis, papillar edema of the eyes, abnormal speech, cerebral edema, delirium, aggressiveness, and psychoses. (L625, L626, L627)

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

Oral (L626) ; inhalation (L626) ; dermal (L626)

Cough. Dizziness. Drowsiness. Headache. Nausea. Weakness. Unconsciousness.

Dry skin. Redness.

Redness.

See Inhalation.

Bromine vapour causes irritation and direct damage to the mucous membranes. Symptoms include lacrimation, rhinorrhoea, eye irritation with mucous secretions from the oropharyngeal and upper airways, coughing, dyspnoea, choking, wheezing, epistaxis, and headache. The bromide ion is a central nervous system depressant producing ataxia, slurred speech, tremor, nausea, vomiting, lethargy, dizziness, visual disturbances, unsteadiness, headaches, impaired memory and concentration, disorientation and hallucinations. This is called bromism. (L626, L627)

Neurotoxin - Acute solvent syndrome

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

Methylene Bromide

9 x 10^-3 mg/kg-day

PDF Document

Inadequate information to assess carcinogenic potential

SCREEN Current

HEAST Archive

PPRTV Current

LC50 (rat) = 40,000 mg/m3/2hr

LD50: 3738 mg/kg (Subcutaneous, Mouse) (T14)

LC50: 40 g/m3 over 2 hours (Inhalation, Rat) (T14)

LC50 Rat ihl 40 g/cu m/2 hr

LD50 Mouse sc 3738 mg/kg

EYES: irrigate opened eyes for several minutes under running water.

INGESTION: do not induce vomiting. Rinse mouth with water (never give anything by mouth to an unconscious person). Seek immediate medical advice.

SKIN: should be treated immediately by rinsing the affected parts in cold running water for at least 15 minutes, followed by thorough washing with soap and water. If necessary, the person should shower and change contaminated clothing and shoes, and then must seek medical attention.

INHALATION: supply fresh air. If required provide artificial respiration.

Treatment of Sprague-Dawley rats with SKF 525-A (39 mg/kg) or diethyl maleate (0.6 ml/kg) 30 min prior to ip admin of 3 mmol/kg dibromomethane resulted in decreased blood carbon monoxide levels.

Basic treatment: Establish a patent airway. Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations as needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Minimize physical activity and provide a quiet atmosphere. Monitor for pulmonary edema and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with normal saline during transport ... . Do not use emetics. Rinse mouth and administer 5 mI/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . Treat frostbite with rapid rewarming techniques ... . /Chlorinated fluorocarbons (CFCs) and related compounds/

Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious or in respiratory arrest. Positive pressure ventilation techniques with a bag valve mask device may be beneficial. Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start an IV with D5W /SRP: "To keep open", minimal flow rate/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. Consider drug therapy for pulmonary edema ... . Treat seizures with diazepam (Valium) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Chlorinated fluorocarbons (CFCs) and related compounds/

... Exerts ... /CNS depression/ and irritant effects; it causes liver and kidney disorders and produces blood changes incl neutrophil leukocytosis with relative lymphocytosis and vitamin C deficiency. Its toxic effects are in many respects similar to those of bromoform; however, bromoform is more toxic than dibromomethane.

METHYLENE BROMIDE IS MORE TOXIC THAN EITHER METHYLENE CHLORIDE OR METHYLENE CHLOROBROMIDE.

MICROBIAL ASSAYS WITH SALMONELLA TYPHIMURIUM, STRAINS TA1535 & TA100, WERE USED TO DETERMINE MUTAGENIC ACTIVITIES OF DIHALOMETHANES. AMONG THE DIHALOMETHANES, METHYLENE BROMIDE WAS THE MOST MUTAGENIC. APPROX MUTAGENIC ACTIVITY WAS 3250 REVERTANTS/PER MILLION CELLS @ 0.3 UL OF METHYLENE BROMIDE IN STRAIN TA100.

THE VAPORS ... MAY CAUSE CARDIAC ARRHYTHMIAS.

... METHYLENE BROMIDE WAS ADMIN ORALLY TO A SMALL GROUP OF RABBITS @ RATE OF 300 MG/KG/DAY (60 DOSES IN 92 DAYS) WITH NO ALTERATION IN WT GAIN, GENERAL APPEARANCE, OR HISTOPATHOLOGY OF THE LIVER. SIMILAR TREATMENT WITH 400 MG/KG OR MORE PRODUCED MARKED ANESTHESIA.

IN ... STUDIES IN WHICH 10 RATS & 1 RABBIT OF EACH SEX WERE EXPOSED TO NOMINAL CONCN OF 1000 PPM (900 TO 1000 PPM RECOVERED ANALYTICALLY), THERE WAS NO OVERT EVIDENCE OF ADVERSE EFFECT IN RABBITS, BUT LIVER & KIDNEY DEGENERATION WERE OBSERVED @ AUTOPSY FOLLOWING 54 EXPOSURES IN 73 DAYS. ... RATS WERE MUCH MORE AFFECTED. INCOORDINATION & STAGGERING WERE APPARENT DURING EXPOSURE. FAILURE TO GAIN WT, POSSIBLE INCREASED MORTALITY, & HISTOPATHOLOGICAL CHANGES IN LUNGS, LIVER, & KIDNEYS WERE OBSERVED IN RATS RECEIVING 30 TO 40 7-HR EXPOSURES.

For more Non-Human Toxicity Excerpts (Complete) data for DIBROMOMETHANE (7 total), please visit the HSDB record page.

2.40e+01

9.90e+01

4.20e+00

2.40e+01

9.90e+01

4.20e+00

1.80e+01

8.30e+00

5.00e-02

2.10e-03

4.00e-03

Volatile

2.82e+03

7.10e+01

3.00e+02

1.30e+01

5.30e+01

2.50e+01

The substance is harmful to aquatic organisms. The substance may cause long-term effects in the aquatic environment.

Dibromomethane's production and use in chemical synthesis, as a fire suppressant, a solvent and a gage fluid may result in its release to the environment through various waste streams. Natural production by marine algae also adds to its environmental input. If released to air, a vapor pressure of 44.4 mm Hg at 25 °C indicates dibromomethane will exist solely as a vapor in the ambient atmosphere. Vapor-phase dibromomethane 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 142 days. If released to soil, dibromomethane is expected to have very high mobility based upon an estimated Koc of 24. Volatilization from moist soil surfaces is expected to be an important fate process based upon a Henry's Law constant of 8.22X10-4 atm-cu m/mole. Dibromomethane may volatilize from dry soil surfaces based upon its vapor pressure. No significant biotic or abiotic degradative processes have been reported in natural waters or soil. However, catalyzed photolysis may occur in surface layers of some natural waters or soil. If released into water, dibromomethane is not expected to adsorb to suspended solids and sediment in water based upon the Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 2 hours and 6 days, respectively. An estimated BCF of 4 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is estimated to be an extremely slow process. Occupational exposure to dibromomethane may occur through inhalation and dermal contact with this compound at workplaces where dibromomethane is produced or used. The general population will be exposed to low levels of dibromomethane in the atmosphere from both natural and anthropogenic sources. (SRC)

Dibromomethane is a primary emission product of macroalgae (eg. Fucales sargassum, Laminariales lamanaria)(1). Macroalgae are often concentrated along beaches and coastlines and releases of dibromomethane occur though dissolution into seawater followed by volatilization into air or direct release by the algae(1). Four of six species of intertidal macroalgae collected from three sites around Cape Cod produced and released dibromomethane into seawater at release rates that ranged up to 2100 ng/g algae (dry wt)(2). Representative species of brown and green algae released dibromomethane while the red algae did not(2).

Dibromomethane is produced by macroalgae(1-4) and microalgae(5). Experimentally-determined production rates for brown, red and green algae collected from the southern California coastal region ranged from 48 to 240 mg dibromomethane /day/g macroalgae (wet weight)(2). Laboratory and in-situ measurements of dibromomethane production by giant kelp (M. Pyrifera) collected from the southern California coastal region ranged from 22-173 (median = 48) ng/day/g of fresh weight and 14-88 (median = 41) ng/day/g of fresh weight, respectively(4). An estimate of the global production of dibromomethane by kelp and nonkelp seaweeds are 1.7 and 0.9 Gg/year(2).

Dibromomethane's production and use in chemical synthesis, as a solvent, or as a gauge fluid(1) may result in its release to the environment through various waste streams. A suggested secondary source of bromomethanes is from the chlorination of seawater in which bromine is relatively abundant(2). However this process predominantly generates bromoform.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 24(SRC), determined from a structure estimation method(2), indicates that dibromomethane is expected to have very high mobility in soil(SRC). Volatilization of dibromomethane from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 8.22X10-4 atm-cu m/mole(3). The potential for volatilization of dibromomethane from dry soil surfaces may exist based upon a vapor pressure of 44.4 mm Hg (4). Biodegradation potential in soil is unknown(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 24(SRC), determined from an estimation method(2), indicates that dibromomethane is not expected to adsorb to suspended solids and sediment in water(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 8.22X10-4 atm-cu m/mole(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 2 hours and 6 days, respectively(SRC). Biodegradation potential in water is unknown(SRC). According to a classification scheme(5), an estimated BCF of 4(SRC), from its log Kow of 1.70(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low. The rate constant for the aqueous-phase reaction of dibromomethane with hydroxyl radicals is 9.9X10+7(8). This corresponds to a half-life of about 22 years at an aqueous concn of 1X10-17 mole/L hydroxyl radicals cm.

ATMOSPHERIC FATE: According to a model of gas partitioning of semivolatile organic compounds in the atmosphere(1), dibromomethane, which has a vapor pressure of 44.4 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase dibromomethane 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 142 days(SRC), calculated from its rate constant of 1.13X10-13 cu cm/molecule-sec at 25 °C(3). The ozone depleting potential and atmospheric lifetime for dibromomethane have been calculated as 0.17 and 0.41 years, respectively(3). Dibromomethane is very soluble in water (11,900 g/l at 30 °C(4)) and therefore it should be readily scavenged by rain and snow(SRC).

The rate constant for the vapor-phase reaction of dibromomethane with photochemically-produced hydroxyl radicals is 1.13X10-13 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 1.4X10+2 days at an atmospheric concn of 5X10+5 hydroxyl radicals per cu cm(1). A base-catalyzed second-order hydrolysis rate constant of 2.5X10-8 L/mole-sec(SRC) was estimated using a structure estimation method(2); this corresponds to half-lives of 9X10+6 and 9X10+5 years at pH values of 7 and 8, respectively(2). The rate constant for the aqueous-phase reaction of dibromomethane with hydroxyl radicals is 9.9X10+7(4). This corresponds to an a half-life of about 22 years at an aqueous concn of 1X10-17 mole/L hydroxyl radicals cm.

An estimated BCF of 4.06 was calculated for dibromomethane(SRC), using a log Kow of 1.70(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.

Using a structure estimation method based on molecular connectivity indices(1), the Koc for dibromomethane can be estimated to be 24(SRC). According to a classification scheme(2), this estimated Koc value suggests that dibromomethane is expected to have very high mobility in soil.

The Henry's Law constant for dibromomethane is 8.22X10-4 atm- cu m/mole(1). This Henry's Law constant indicates that dibromomethane is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 2 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 5 days(SRC). Dibromomethane's Henry's Law constant(1) indicates that volatilization from moist soil surfaces may occur(SRC). Dibromomethane is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 44.4 mm Hg(3).

DRINKING WATER: In a survey of 14 treated drinking water supplies of varied sources in England, dibromomethane was detected in seven supplies(1). These supplies were derived from groundwater and surface water sources. Dibromomethane was detected in treated drinking water from the Niagara River in the range 0.2-0.8 ppb(2).

GROUNDWATER: No detectible dibromomethane was found in samples from a study of groundwater contamination at 19 municipal and 6 industrial landfill sites in Wisconsin(1). Of the 377 and 282 representative samples of groundwater and surface water in New Jersey that were analyzed for dibromomethane, 12% and 28%, respectively, contained dibromomethane(2). Ninety precent of the samples of both types contained equal or less than 0.1 ppb of dibromomethane(2). The maximum dibromomethane concentration in groundwater was 44.9 ppb and that in surface water was 358.6 ppb(2) Dibromomethane was found at 9 of 17 stations in the Lower Niagara River; levels up to 5 parts per trillion were found(3).

SURFACE WATER: Dibromomethane is a major volatile organic hydrocarbon in Narraganset Bay(1). However levels and distribution of the chemical were not reported. Surface seawater concns of dibromomethane at a site in the South Atlantic, and two sites in the North Atlantic (south of the Canary Islands and west of the Strait of Gibraltar) were 0.26, >1, and 0.3 ng/l(2). In Lake Ontario, dibromomethane was detected in 66% of the 82 stations that were sampled(3). Only 8 samples contained more than trace amounts of dibromomethane and the highest level was 7 parts per trillion. The detection limit was 0.7 parts per trillion. Dibromomethane was detected in surface water samples collected from 58 stations in the Northwest Atlantic Ocean between April 27 and May 31, 1991 at concns ranging from approximately 0.1 to 1.4(4). Dibromomethane was detected in 34 surface water samples collected in the antarctic between October and December of 1987 at concns ranging from 0.38-4.44 ng/l with a mean of 0.94 ng/l(5). Dibromomethane was detected in 3 of 136 samples collected from 30 sites along the lower reach of the Yodo River and its tributaries and the lower reaches of the Neyagawa River basin, near Osaka, Japan between August 1993 and February 1995 at concns between approximately 0.15 and 7 ug/l(6).

RAIN/SNOW: The concentration of dibromomethane in rain collected in Ulm, southern Germany was 1.4 ng/l(1). This rain was in a fast moving front coming from the North Atlantic.

In a comprehensive survey of wastewater from 4000 industrial and publicly owned treatment works (POTWs) sponsored by the Effluent Guidelines Division of the U.S. EPA, dibromomethane was identified in discharges of the following industrial categories (positive occurrences, median concn in ppb): nonferrous metals (8; 2.2), organics and plastics (2; 32.9), inorganic chemicals (2; 1.9), pesticides manufacture (2; 104.6), publicly owned treatment works (9; 0.3)(1). Maximum effluent concn >100 ppb were found in the nonferrous metals industry (286 ppb) and in pesticide manufacturing (151 ppb)(1). In a previous survey of 63 wastewaters from a wide range of chemical manufacturers across the U.S., 1 effluent contained dibromomethane(2). The level of dibromomethane in that sample was >100 ppb.

SOURCE DOMINATED: The median concentration of dibromomethane from six source-related areas in the U.S. (22 measurement), namely, Edison, NJ, Magnolia,AR, Phoenix, AZ, Seattle, WA, Sugas Creek, MO, and Westwood Village, CA was 980 parts per trillion; the range was 190-13,000 parts per trillion(1).

URBAN/SUBURBAN: Dibromomethane was detected in air samples collected in Patterson, Edison and E. Brunswick, NJ in 1976 at concns of 130, 63,000 and 42 ng/cu m, respectively. Dibromomethane was detected in four samples collected in Tsukuba, Japan in April, 1992 at concns ranging from 0.70-1.28 parts per trillion (2). The concn of dibromomethane in air samples collected at Otake Beach, located approximately 50 km east of Tsukuba, ranged from 0.90-1.31 parts per trillion(2).

RURAL/REMOTE: The baseline concn of dibromomethane in marine air far removed from coastal areas and large concns of macroalgae is 2.4 parts per trillion/volume(1). The level of dibromomethane in air decreases with altitude to 1.2 parts per trillion/volume above the marine boundary layer and tradewind inversion(1). Air samples were collected in the South and North Atlantic on a cruise from Capetown to Bremerhaven, on the Azores, Madeira, Bermuda, and Tenerife. The dibromomethane concns reported ranged from 0.8 to 4 parts per trillion/volume with the exception of the beach at Sao Miguel, the Azores which was 50 parts per trillion/volume(1). The concn of dibromomethane measured across the Arctic from Anchorage, AK to Norway and the North Pole during March and April 1983 ranged from 3-60 parts per trillion/volume with a mean of 15 (standard deviation= 12) parts per trillion/volume(3). The monthly average concn of dibromomethane at Point Barrows, AK during 1983 ranged from 4.7 to 5.6 parts per trillion/volume(2). The concn within the Arctic haze that seasonally occurs in Point Barrows is estimated to be 4.2 parts per trillion/volume, while that outside the haze is 2.5 parts per trillion/volume(2). The concn is highest in winter and spring at which times meteorological and atmospheric conditions favor the formation of Arctic haze(2,3). This suggests that dibromomethane may be transported from industrial sources in the mid-latitudes(2). Dibromomethane was measured in background Arctic air and in Arctic haze between March 31 and April 4, 1984 (4). The difference in concn of dibromomethane between the background air and haze was measured as 1.7 parts per trillion/volume(4). Dibromomethane was detected in 67 air samples collected in the Antarctic between October and December of 1987 at concns ranging from 0.3-8.6 parts per trillion/volume with a mean of 3.7 parts per trillion/volume (5). Dibromomethane was detected in air samples collected during three sampling efforts: in the western Pacific between January 31 and February 1991 at concns ranging from 0.47-1.36 parts per trillion/volume, with a mean of 0.87 (n=23); in the western Pacific between September and October 1992 at concns ranging from 0.14-1.58 parts per trillion/volume with a mean of 0.59 parts per trillion/volume (n=48); and in the East China Sea, South China Sea and Bay of Bengal between January and March 1994 at concns ranging from 0.38-1.42 parts per trillion/volume, with a mean of 0.77 parts per trillion/volume (n=73)(6).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 1065 workers (452 of these are female) are potentially exposed to dibromomethane in the US(1). Occupational exposure to dibromomethane may occur through inhalation and dermal contact with this compound at workplaces where dibromomethane is produced or used(SRC). The general population may be exposed to dibromomethane via inhalation of ambient air, ingestion of food and drinking water, and dermal contact with this compound and other products containing dibromomethane(SRC).

AIR INTAKE: Remote areas (assume air concn of 2.4-15 parts per trillion (1,2) and inhalation rate of 20 cu meters/day (4)) - 0.3-2.2 ug, Source areas (assume air concn of 900 parts per trillion(3) and inhalation rate of 20 cu meters/day (4)) - 130 ug; WATER INTAKE: insufficient data; FOOD INTAKE: insufficient data(SRC).

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U068, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

A potential candidate for rotary kiln incineration at a temperature range of 820 to 1,600 °C and residence times of seconds for liquids and gases, and hours for solids. A potential candidate for fluidized bed incineration at a temperature range of 450 to 980 °C and residence times of seconds for liquids and gases, and longer for solids.

/GUIDE 160: HALOGENATED SOLVENTS/ Fire or Explosion: 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.

/GUIDE 160: HALOGENATED SOLVENTS/ Health: 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.

/GUIDE 160: HALOGENATED SOLVENTS/ Public Safety: CALL Emergency Response Telephone Number on Shipping Paper first. If Shipping Paper not available or no answer, refer to appropriate telephone number listed on the inside back cover. As an immediate precautionary measure, isolate spill or leak area for at least 50 meters (150 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Many gases are heavier than air and will spread along ground and collect in low or confined areas (sewers, basements, tanks). Keep out of low areas. Ventilate closed spaces before entering.

/GUIDE 160: HALOGENATED SOLVENTS/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. Structural firefighters' protective clothing will only provide limited protection.

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

UN 2664; Dibromomethane

IMO 6.1; Dibromomethane

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

Do not transport with food and feedstuffs.

Symbol: Xn; R: 20-52/53; S: (2)-24-61

UN Hazard Class: 6.1; UN Pack Group: III