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Chemical Datasheet

METHYL BROMIDE AND NONFLAMMABLE, NONLIQUEFIED COMPRESSED GAS MIXTURE

2.3 - Poisonous gas
Chemical Identifiers | Hazards | Response Recommendations | Physical Properties | Regulatory Information | Alternate Chemical Names

Chemical Identifiers

The Chemical Identifier fields include common identification numbers, the NFPA diamond U.S. Department of Transportation hazard labels, and a general description of the chemical. The information in CAMEO Chemicals comes from a variety of data sources.
CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 74-83-9   (METHYL BROMIDE)
  • Poison Gas
none
NIOSH Pocket Guide International Chem Safety Card
Methyl bromideexternal_link
NFPA 704
Diamond Hazard Value Description
1
3 0
Blue Health 3 Can cause serious or permanent injury.
Red Flammability 1 Must be preheated before ignition can occur.
Yellow Instability 0 Normally stable, even under fire conditions.
White Special
Note: NFPA ratings shown are for methyl bromide, CAS number 74-83-9.
(NFPA, 2010)
General Description
A colorless odorless gas at room temperature and pressure. Readily liquefied by moderate pressure or by cooling to 4.5oC. A poison that causes respiratory distress and neurotoxic effects from which recovery may be slow. Often "stenched" with chloropicrin in use, which adds an irritating chloroform-like odor. Prolonged or repeated skin contact may cause severe burns and possible absorption of toxic quantities. Mixed with a non-reactive, nonflammable gas to dilute and carry for use as a fumigant. This mixture is then handled as a gas. Under prolonged exposure to fire or intense heat the container may rupture violently and rocket.

Hazards

The Hazard fields include special hazard alerts air and water reactions, fire hazards, health hazards, a reactivity profile, and details about reactive groups assignments and potentially incompatible absorbents. The information in CAMEO Chemicals comes from a variety of data sources.
Reactivity Alerts
none
Air & Water Reactions
Even pure methyl bromide is nonflammable over a wide range of concentrations in air. Thus this mixture presents practically no fire hazard. Slightly water soluble (NTP, 1992). Methyl bromide reacts with water to generate hydrobromic acid and methanol but the reaction is so slow that it can be disregarded for most practical purposes.
Fire Hazard
Excerpt from ERG Guide 123 [Gases - Toxic]:

Some may burn but none ignite readily. Vapors from liquefied gas are initially heavier than air and spread along ground. Cylinders exposed to fire may vent and release toxic and/or corrosive gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket. (ERG, 2020)
Health Hazard
Excerpt from ERG Guide 123 [Gases - Toxic]:

TOXIC; may be fatal if inhaled or absorbed through skin. Vapors may be irritating and/or corrosive. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may cause environmental contamination. (ERG, 2020)
Reactivity Profile
METHYL BROMIDE is incompatible with metals, dimethyl sulfoxide, ethylene oxide. [Lewis]. Can give flammable products if mixed with potassium hydroxide, sodium hydroxide and other strong bases. Methyl bromide in a steel tank reacted with an aluminum tube (part of the level gauge) producing methyl aluminum bromide. When the latter was subsequently exposed to air, enough heat was produced to ignite the methyl bromide-compressed air mixture above the liquid layer. The ensuing explosion shattered the tank (also incompatible with zinc, magnesium, and alloys)[Chem. Eng. Pro. 58(8). 1962]. A reaction between methyl bromide and dimethyl sulfoxide resulted in an explosion that shattered the apparatus [NFPA 491M. 1991].
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

No information available.

Response Recommendations

The Response Recommendation fields include isolation and evacuation distances, as well as recommendations for firefighting, non-fire response, protective clothing, and first aid. The information in CAMEO Chemicals comes from a variety of data sources.
Isolation and Evacuation
Excerpt from ERG Guide 123 [Gases - Toxic]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area for at least 100 meters (330 feet) in all directions.

SPILL: See ERG Table 1 - Initial Isolation and Protective Action Distances on the UN/NA 1955 datasheet.

FIRE: If tank, rail car or tank truck 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, 2020)
Firefighting
Excerpt from ERG Guide 123 [Gases - Toxic]:

SMALL FIRE: Dry chemical or CO2.

LARGE FIRE: Water spray, fog or regular foam. Do not get water inside containers. If it can be done safely, move undamaged containers away from the area around the fire. Damaged cylinders should be handled only by specialists.

FIRE INVOLVING 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. Do not direct water at source of leak or safety devices; icing may occur. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. (ERG, 2020)
Non-Fire Response
Excerpt from ERG Guide 123 [Gases - Toxic]:

Do not touch or walk through spilled material. Stop leak if you can do it without risk. If possible, turn leaking containers so that gas escapes rather than liquid. Prevent entry into waterways, sewers, basements or confined areas. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Do not direct water at spill or source of leak. Isolate area until gas has dispersed. (ERG, 2020)
Protective Clothing
Excerpt from ERG Guide 123 [Gases - Toxic]:

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. (ERG, 2020)
DuPont Tychem® Suit Fabrics
Tychem® Fabric Legend
QS = Tychem 2000 SFR
QC = Tychem 2000
SL = Tychem 4000
C3 = Tychem 5000
TF = Tychem 6000
TP = Tychem 6000 FR
RC = Tychem RESPONDER® CSM
TK = Tychem 10000
RF = Tychem 10000 FR
Testing Details
The fabric permeation data was generated for DuPont by a third party laboratory. Permeation data for industrial chemicals is obtained per ASTM F739. Normalized breakthrough times (the time at which the permeation rate exceeds 0.1 μg/cm2/min) are reported in minutes. All chemicals have been tested between approximately 20°C and 27°C unless otherwise stated. All chemicals have been tested at a concentration of greater than 95% unless otherwise stated.
Chemical warfare agents (Lewisite, Sarin, Soman, Sulfur Mustard, Tabun and VX Nerve Agent) have been tested at 22°C and 50% relative humidity per military standard MIL-STD-282. "Breakthrough time" for chemical warfare agents is defined as the time when the cumulative mass which permeated through the fabric exceeds the limit in MIL-STD-282 [either 1.25 or 4.0 μg/cm2].
A Caution from DuPont
This information is based upon technical data that DuPont believes to be reliable on the date issued. It is subject to revision as additional knowledge and experience are gained. The information reflects laboratory performance of fabrics, not complete garments, under controlled conditions. It is intended for informational use by persons having technical skill for evaluation under their specific end-use conditions, at their own discretion and risk. It is the user's responsibility to determine the level of toxicity and the proper personal protective equipment needed. Anyone intending to use this information should first verify that the garment selected is suitable for the intended use. In many cases, seams and closures have shorter breakthrough times and higher permeation rates than the fabric. If fabric becomes torn,abraded or punctured, or if seams or closures fail, or if attached gloves, visors, etc. are damaged, end user should discontinue use of garment to avoid potential exposure to chemical. Since conditions of use are outside our control, DuPont makes no warranties, express or implied, including, without limitation, no warranties of merchantability or fitness for a particular use and assume no liability in connection with any use of this information. This information is not intended as a license to operate under or a recommendation to infringe any patent, trademark or technical information of DuPont or others covering any material or its use.
Normalized Breakthrough Times (in Minutes)
Chemical CAS Number State QS QC SL C3 TF TP RC TK RF
Bromo methane 74-83-9 Vapor >480 >480 >480 >480
Methyl bromide 74-83-9 Vapor >480 >480 >480 >480
> indicates greater than.

Special Warning from DuPont: Tychem® and Tyvek® fabrics should not be used around heat, flames, sparks or in potentially flammable or explosive environments. Only...

...Tychem® ThermoPro, Tychem® Reflector® and Tychem® TK styles 600T/601T (with aluminized outer suit) garments are designed and tested to help reduce burn injury during escape from a flash fire. Users of Tychem® ThermoPro, Tychem® Reflector® and Tychem® TK styles 600T/601T (with aluminized outer suit) garments should not knowingly enter an explosive environment. Tychem® garments with attached socks must be worn inside protective outer footwear and are not suitable as outer footwear. These attached socks do not have adequate durability or slip resistance to be worn as the outer foot covering.

(DuPont, 2023)

First Aid
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.

SKIN: CAUTION: Exposure of skin to compressed gases may result in freezing of the skin. Treatment for frostbite may be necessary. Remove the victim from the source of contamination. IMMEDIATELY wash affected areas gently with COLD water (and soap, if necessary) while removing and isolating all contaminated clothing. Dry carefully with clean, soft towels. Call a hospital or poison control center IMMEDIATELY even if no symptoms (such as inflammation or irritation) develop. Be prepared to transport the victim to a hospital for treatment after washing the affected area if advised to do so by a physician.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: This compound is a gas, therefore inhalation is the first route of exposure.

OTHER: Since this chemical is a known or suspected carcinogen you should contact a physician for advice regarding the possible long term health effects and potential recommendation for medical monitoring. Recommendations from the physician will depend upon the specific compound, its chemical, physical and toxicity properties, the exposure level, length of exposure, and the route of exposure. (NTP, 1992)

Physical Properties

The Physical Property fields include properties such as vapor pressure and boiling point, as well as explosive limits and toxic exposure thresholds The information in CAMEO Chemicals comes from a variety of data sources.

Note: For Vapor Density and Specific Gravity, comparing the value to 1.0 can tell you if the chemical will likely sink/rise in air or sink/float in fresh water (respectively). Short phrases have been added to those values below as an aid. However, make sure to also consider the circumstances of a release. The Vapor Density comparisons are only valid when the gas escaping is at the same temperature as the surrounding air itself. If the chemical is escaping from a container where it was pressurized or refrigerated, it may first escape and behave as a heavy gas and sink in the air (even if it has a Vapor Density value less than 1). Also, the Specific Gravity comparisons are for fresh water (density 1.0 g/mL). If your spill is in salt water (density about 1.027 g/mL), you need to adjust the point of comparison. There are some chemicals that will sink in fresh water and float in salt water.
Chemical Formula:
  • CH3Br
Flash Point: data unavailable
Lower Explosive Limit (LEL): 13.5 % (NTP, 1992)
Upper Explosive Limit (UEL): 14.5 % (NTP, 1992)
Autoignition Temperature: 999°F (NTP, 1992)
Melting Point: -135°F (NTP, 1992)
Vapor Pressure: 1250 mmHg at 68°F (NTP, 1992)
Vapor Density (Relative to Air): 3.3 (NTP, 1992) - Heavier than air; will sink
Specific Gravity: 1.6755 at 68°F (NTP, 1992) - Denser than water; will sink
Boiling Point: 38.41°F at 760 mmHg (NTP, 1992)
Molecular Weight: 94.94 (NTP, 1992)
Water Solubility: Slightly soluble (NTP, 1992)
Ionization Energy/Potential: 10.54 eV [From NPG: Methyl bromide] (NIOSH, 2023)
IDLH: 250 ppm ; A potential occupational carcinogen. [From NPG: Methyl bromide] (NIOSH, 2023)

AEGLs (Acute Exposure Guideline Levels)

Final AEGLs for Methyl bromide (74-83-9)
Exposure Period AEGL-1 AEGL-2 AEGL-3
10 minutes NR 940 ppm 3300 ppm
30 minutes NR 380 ppm 1300 ppm
60 minutes NR 210 ppm 740 ppm
4 hours NR 67 ppm 230 ppm
8 hours NR 67 ppm 130 ppm
NR = Not recommended due to insufficient data
(NAC/NRC, 2023)

ERPGs (Emergency Response Planning Guidelines)

Chemical ERPG-1 ERPG-2 ERPG-3
Methyl Bromide (74-83-9) NA 100 ppm 300 ppm
NA = not appropriate.
(AIHA, 2022)

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Methyl bromide; (Bromomethane) (74-83-9) 19 ppm 210 ppm 740 ppm LEL = 100000 ppm
(DOE, 2018)

Regulatory Information

The Regulatory Information fields include information from the U.S. Environmental Protection Agency's Title III Consolidated List of Lists, the U.S. Cybersecurity and Infrastructure Security Agency's Chemical Facility Anti-Terrorism Standards, and the U.S. Occupational Safety and Health Administration's Process Safety Management of Highly Hazardous Chemicals Standard List (see more about these data sources).

EPA Consolidated List of Lists

Regulatory Name CAS Number/
313 Category Code
EPCRA 302
EHS TPQ
EPCRA 304
EHS RQ
CERCLA RQ EPCRA 313
TRI
RCRA
Code
CAA 112(r)
RMP TQ
Bromomethane 74-83-9 1000 pounds 1000 pounds 1000 pounds 313 U029
Methyl bromide 74-83-9 1000 pounds 1000 pounds 1000 pounds X U029

(EPA List of Lists, 2022)

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

No regulatory information available.

OSHA Process Safety Management (PSM) Standard List

Chemical Name CAS Number Threshold Quantity (TQ)
Methyl Bromide 74-83-9 2500 pounds

(OSHA, 2019)

Alternate Chemical Names

This section provides a listing of alternate names for this chemical, including trade names and synonyms.