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CHEMINFO Record Number: 644
CCOHS Chemical Name: Methylene bromide

Methylene dibromide

Chemical Name French: Bromure de méthylène
Chemical Name Spanish: Bromuro de metileno
CAS Registry Number: 74-95-3
UN/NA Number(s): 2664
RTECS Number(s): PA7350000
EU EINECS/ELINCS Number: 200-824-2
Chemical Family: Halogenated aliphatic hydrocarbon / saturated halogenated hydrocarbon / halogenated alkane / haloalkane / dihaloalkane / bromoalkane / dibromoalkane
Molecular Formula: C-H2-Br2
Structural Formula: Br-CH2-Br


Appearance and Odour:
Clear, colourless liquid

Odour Threshold:
No information available

Warning Properties:
Insufficient information for evaluation

Uses and Occurrences:
Used primarily as a solvent; also used as an intermediate in organic synthesis (for example, production of herbicides).


Clear, colourless liquid. Will not burn. Can decompose at high temperatures forming toxic gases such as hydrogen bromide. Central nervous system depressant. Vapour may cause headache, nausea, dizziness, drowsiness, incoordination, confusion, unconsciousness and death.


Effects of Short-Term (Acute) Exposure

Methylene bromide may cause slight nose and throat irritation as well as central nervous system (CNS) depression.
Low concentrations may cause mild CNS depression characterized by light-headedness, dizziness, nausea, numbness in hands and feet, fatigue, inability to concentrate, and reduced coordination.
Prolonged and/or repeated high-level exposures may cause liver and kidney damage. Very high concentrations may result in loss of consciousness and death.
No human information is available. These effects were observed in limited animal studies with methylene bromide and in studies of a related chemical, methylene chloride (CHEMINFO 76E).

Skin Contact:
Methylene bromide has been described as a slight skin irritant in animals. As well, methylene bromide vapours were absorbed through the skin in animal tests. The effects of extensive absorption through the skin may be similar to those described for inhalation.

Eye Contact:
Methylene bromide has been described as a slight eye irritant in animals. A similar chemical, methylene chloride, is an irritant. Therefore, the liquid or concentrated vapours may cause irritation. The liquid may also cause temporary corneal damage.

Methylene bromide is not very toxic in short-term ingestion studies with animals. High doses may result in CNS depression. Symptoms would be similar to those described for inhalation.

Effects of Long-Term (Chronic) Exposure

There is one unconfirmed report of workers exposed to unspecified concentrations of both methylene bromide and tetrabromoethane.
After exposure for one to one and a half years, a number of workers reported CNS and behavioural problems such as dizziness, headaches, irritability, emotional instability and memory loss. Some symptoms were still observed one year after removal from the exposure area.(8)
Limited animal information and information for a very similar chemical (methylene chloride), suggests that prolonged and/or repeated exposures to near-fatal concentrations may result in CNS depression and liver, kidney and lung damage.


No information available.

The International Agency for Research on Cancer (IARC) has not evaluated the carcinogenicity of this chemical.

The American Conference of Governmental Industrial Hygienists (ACGIH) has no listing for this chemical.

The US National Toxicology Program (NTP) has not listed this chemical in its report on carcinogens.

Teratogenicity and Embryotoxicity:
No information available

Reproductive Toxicity:
No information available

Methylene bromide was weakly positive in short-term bacterial tests. No animal or human data is available.

Toxicologically Synergistic Materials:
No information available

Potential for Accumulation:
Methylene bromide is metabolized to carbon monoxide, formic acid and bromide.(3,9) The presence of carbon monoxide may cause elevated blood levels of carboxyhemoglobin.(1,3)


Take proper precautions to ensure your own safety before attempting rescue (e.g. wear appropriate protective equipment, use buddy system). Remove source of contamination or move victim to fresh air. If breathing is difficult, trained personnel should begin artificial respiration (AR) or, if the heart has stopped, cardiopulmonary resuscitation (CPR) immediately. Avoid mouth-to-mouth contact. Immediately transport victim to an emergency care facility.

Skin Contact:
As quickly as possible, flush contaminated area with lukewarm, gently running water for at least 20 minutes or until the chemical is removed. Under running water, remove contaminated clothing, shoes, and leather goods (e.g., watchbands, belts). If irritation persists, repeat flushing. If breathing has stopped, trained personnel should begin artificial respiration (AR) or, if the heart has stopped, cardiopulmonary resuscitation (CPR). Obtain medical attention immediately. Completely decontaminate clothing before re-use or discard. Do not re-use contaminated shoes or leather goods.

Eye Contact:
Immediately flush the contaminated eye(s) with lukewarm, gently flowing water for 5 minutes, or until the chemical is removed, holding the eyelid(s) open. Obtain medical advice immediately.

Never give anything by mouth if victim is rapidly losing consciousness, is unconscious or convulsing. Have victim rinse mouth thoroughly with water. DO NOT INDUCE VOMITING. Have victim drink 240 to 300 mL (8 to 10 oz.) of water. If vomiting occurs naturally, rinse mouth and repeat administration of water. If breathing has stopped, trained personnel should begin artificial respiration (AR) or, if the heart has stopped, cardiopulmonary resuscitation (CPR) immediately. Avoid mouth-to-mouth contact. Quickly transport victim to an emergency care facility.

First Aid Comments:
Provide general supportive measures (comfort, warmth, rest).
Consult a doctor and/or the nearest Poison Control Centre for all exposures except minor instances of inhalation or skin contact.
All first aid procedures should be periodically reviewed by a doctor familiar with the material and its conditions of use in the workplace.


Flash Point:
Not applicable (does not burn)

Lower Flammable (Explosive) Limit (LFL/LEL):
Not applicable

Upper Flammable (Explosive) Limit (UFL/UEL):
Not applicable

Autoignition (Ignition) Temperature:
Not applicable

Sensitivity to Mechanical Impact:
No information, but expected to be stable under normal conditions.

Sensitivity to Static Charge:
Not sensitive (does not burn).

Combustion and Thermal Decomposition Products:
Hydrogen bromide

Fire Hazard Summary:
During a fire, irritating/toxic gases such as hydrogen bromide and carbon monoxide may be generated.

Extinguishing Media:
Will not burn. Use extinguishing media suitable for surrounding materials.

Fire Fighting Instructions:
Methylene bromide does not burn. If it can be done without risk, move fire-exposed containers to a safe area. Use water spray to cool fire-exposed containers. Water spray may be used to flush spills away and prevent exposure.
As in any fire, wear self-contained breathing apparatus (SCBA), pressure-demand, (MSHA/NIOSH approved or equivalent) and full protective equipment (Bunker Gear).


NFPA - Comments:
NFPA has no listing for this chemical in Codes 49 or 325.


Molecular Weight: 173.85

Conversion Factor:
1 ppm = 7.31 mg/m3; 1 mg/m3 = 0.14 ppm at 25 deg C

Physical State: Liquid
Melting Point: -52 deg C (-62 deg F)
Boiling Point: 97 deg C (207 deg F)
Relative Density (Specific Gravity): 2.490 at 25 deg C (water = 1)
Solubility in Water: Moderately soluble (1.18 g/100 mL of water at 20 deg C)
Solubility in Other Liquids: Soluble in alcohol, ether, chloroform and acetone.
Coefficient of Oil/Water Distribution (Partition Coefficient): Not available
pH Value: Not available
Vapour Density: 6.05 (air = 1) (9)
Vapour Pressure: 35 mm Hg at 20 deg C (7); 48 mm Hg at 25 deg C (1)
Saturation Vapour Concentration: 63000 ppm at 25 deg C (calc)
Evaporation Rate: Not available
Critical Temperature: Not available


No information available. Probably stable.

Hazardous Polymerization:
Not expected

Incompatibility - Materials to Avoid:

NOTE: Chemical reactions that could result in a hazardous situation (e.g. generation of flammable or toxic chemicals, fire or detonation) are listed here. Many of these reactions can be done safely if specific control measures (e.g. cooling of the reaction) are in place. Although not intended to be complete, an overview of important reactions involving common chemicals is provided to assist in the development of safe work practices.

STRONG OXIDIZERS - may react vigorously.

STRONG BASES - may react vigorously.

METALS (eg. aluminum, magnesium, potassium) - forms compounds which are shock sensitive and may explode.(6,7)

Hazardous Decomposition Products:
No information available

Corrosivity to Metals:
No information available


LC50 (rat): 40000 mg/m3 (5600 ppm) (2-hour exposure) (2)

LD50 (oral, rat): Greater than 1000 mg/kg (1)

Eye Irritation:

Caused slight irritation in rabbits.(1)

Skin Irritation:

Caused slight irritation in rabbits.(1)

Effects of Short-Term (Acute) Exposure:

Animals exposed, for an unspecified period of time, to 2400-2800 ppm (17000-20000 mg/m3) developed central nervous system (CNS) disorders; no further details are available.(1)

Skin Contact:
The vapours were absorbed through the skin of rats in one animal study.(4)

Effects of Long-Term (Chronic) Exposure:

Rabbits exposed to approximately 1000 ppm, 54 times within 73 days, showed no obvious problems during the study. However, liver and kidney damage were observed during autopsy. Rats similarly exposed showed signs of CNS disorders (staggering, incoordination) during the exposure period. As well, the rats did not gain weight and there was a possible increased death rate.(1) Liver, kidney and lung damage were observed in rats receiving 30-40, 7-hour exposures at 1000 ppm. Similar exposure of rats and rabbits to 200 ppm produced only minor signs of stress and microscopic changes in the liver and kidneys.(1)

In a very limited study, 60 doses of 300 mg/kg/day over a 92 day period did not appear to cause any problems in rabbits; similar treatment with 400 mg/kg or more did produce loss of feeling (anesthesia).(1)


Selected Bibliography:
(1) Patty's industrial hygiene and toxicology. 3rd rev. ed. Vol. 2B. John Wiley & Sons, 1981. p. 3459-3461
(2) RTECS record for methane, dibromo-. Date of last update 9201
(3) Ullmann's encyclopedia of industrial chemistry. 5th rev. ed. Vol. A4. VCH Verlagsgesellschaft, 1985. p. 413-429
(4) McDougal, J.N., et al. Dermal absorption of dihalomethane vapors. Toxicology and Applied Pharmacology. Vol. 79, no. 1 (1985). p. 150-158
(5) Forsberg, K., et al. Quick selection guide to chemical protective clothing. 4th ed. Van Nostrand Reinhold, 2002
(6) Bretherick, L. Bretherick's handbook of reactive chemical hazards. 3rd ed. Butterworths, 1990. p. 1288-1289
(7) The Sigma-Aldrich library of chemical safety data. Edition II. Vol. 1. Sigma-Aldrich, 1988. p. 1082C
(8) Danilin, V.A., et al. The problem of chronic poisoning from tetrabromoethane and methylene bromide (clinical observations). Gigiena Truda i Professional'nye Zabolevaniya. Vol. 12, no. 12 (1968). p. 39-40
(9) HSDB record for methylene bromide. Last revision date: 90/11/02
(10) European Communities (EC). Commission Directive 2004/73/EC. Apr. 29, 2004
(11) NIOSH pocket guide to chemical hazards. NIOSH, June 1994. p. 200-201

Information on chemicals reviewed in the CHEMINFO database is drawn from a number of publicly available sources. A list of general references used to compile CHEMINFO records is available in the database Help.

Review/Preparation Date: 1992-11-12

Revision Indicators:
Trans PEL-TWA 1993-04-01
TDG 1994-02-01
WHMIS (detailed class) 1994-03-01
Sampling 1996-06-01
Protective equipment 1996-06-01
EU number 1996-06-01
US transport 1998-03-01
Resistance of materials 1998-05-01
EU Risk 1998-11-01
EU Safety 1998-11-01
Resistance of materials for PPE 2004-03-28
Bibliography 2004-11-29
EU classification 2004-11-29
EU comments 2004-11-29

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