Substance profile
Bromomethane
Bromomethane is colorless, transparent, easily liquified gas or volatile liquid and is odorless.
01 · Identification
What Bromomethane is
Bromomethane is colorless, transparent, easily liquified gas or volatile liquid and is odorless. Its molecular formula is CH3Br and its molecular weight is 94.94 g/mol. It boils at 3.4 °C, melts at -93.7 °C.
Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).
02 · Identifiers
Bromomethane identifiers and molecular data
Bromomethane CAS number and EC number
Bromomethane molecular formula and molecular weight
Other names for Bromomethane
- methylbromide
03 · GHS classification
Bromomethane hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Bromomethane pictograms and signal word
Bromomethane hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Acute toxicity - oral GHS chapter 3.1 | Category 3 | H301 | GHS06 |
| Acute toxicity - inhalation GHS chapter 3.1 | Category 3 | H331 | GHS06 |
| Skin corrosion/irritation GHS chapter 3.2 | Category 2 | H315 | GHS07 |
| Serious eye damage/eye irritation GHS chapter 3.3 | Category 2A | H319 | GHS07 |
| Germ cell mutagenicity GHS chapter 3.5 | Category 2 | H341 | GHS08 |
| Specific target organ toxicity - single exposure GHS chapter 3.8 | Category 3 | H335 | GHS07 |
| Specific target organ toxicity - repeated exposure GHS chapter 3.9 | Category 2 | H373 | GHS08 |
| Hazardous to the aquatic environment - acute GHS chapter 4.1 | Category 1 | H400 | GHS09 |
| Hazardous to the ozone layer GHS chapter 4.2 | Category 1 | H420 | GHS07 |
Bromomethane hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H341 | Suspected of causing genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H331 | Toxic if inhaled. |
| H301 | Toxic if swallowed. |
| H335 | May cause respiratory irritation. |
| H373 | May cause damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H315 | Causes skin irritation. |
| H319 | Causes serious eye irritation. |
| H400 | Very toxic to aquatic life. |
| H420 | Harms public health and the environment by destroying ozone in the upper atmosphere |
This page lists only the codes assigned to Bromomethane. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.
Safety Data Sheet
Getting an SDS for Bromomethane
A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of Bromomethane issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.
04 · Precautionary statements
Bromomethane precautionary statements
CLP Annex VI assigns 22 precautionary statements to Bromomethane. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.
Prevention
What to do before and during handling so the hazard never happens.
Response
What to do once exposure, spillage or fire has already happened.
Disposal
What has to happen to the contents and the empty container.
Reading the notation. … is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.
05 · Names in the regulation
Bromomethane name in 23 EU languages
CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.
| Language | Name in CLP Annex VI Part 3 |
|---|---|
| Bulgarian български | бромометан метилбромид |
| Spanish español | Bromometano bromuro de metilo |
| Czech čeština | brommethan methylbromid |
| Danish dansk | brommethan methylbromid |
| German Deutsch | Brommethan Methylbromid |
| Estonian eesti | bromometaan metüülbromiid |
| Greek ελληνικά | βρωμομεθάνιο μεθυλοβρωμίδιο |
| English English | bromomethane methylbromide |
| French français | bromométhane bromure de méthyle |
| Croatian hrvatski | brommetan metil-bromid |
| Italian italiano | bromometano metilbromuro |
| Latvian latviešu | brommetāns metilbromīds |
| Lithuanian lietuvių | brommetanas metilbromidas |
| Hungarian magyar | brómmetán metil-bromid |
| Maltese Malti | bromometan metilbromur |
| Dutch Nederlands | broommethaan methylbromide |
| Polish polski | bromometan bromek metylu |
| Portuguese português | bromometano brometo de metilo |
| Romanian română | bromometan bromură de metil |
| Slovak slovenčina | brómmetán metylbromid |
| Slovenian slovenščina | bromometan metilbromid |
| Finnish suomi | bromimetaani metyylibromidi |
| Swedish svenska | brommetan metylbromid |
All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.
06 · Label elements
Bromomethane GHS label elements
Everything CLP Annex VI fixes for Bromomethane, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Bromomethane
- Suspected of causing genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- Toxic if inhaled.
- Toxic if swallowed.
- May cause respiratory irritation.
- May cause damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- Causes skin irritation.
- Causes serious eye irritation.
- Very toxic to aquatic life.
- Harms public health and the environment by destroying ozone in the upper atmosphere
- Obtain special instructions before use.
- Do not breathe dust/fume/gas/mist/vapours/spray.
- Wash … thoroughly after handling.
- Do not eat, drink or smoke when using this product.
- Use only outdoors or in a well-ventilated area.
- Avoid release to the environment.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- IF ON SKIN:
- IF INHALED:
- IF IN EYES:
- IF exposed or concerned:
- Immediately call a POISON CENTER/doctor/…
- Get medical advice/attention.
- Get medical advice/attention if you feel unwell.
- Rinse mouth.
- If skin irritation occurs:
- If eye irritation persists:
- Remove contact lenses, if present and easy to do. Continue rinsing.
- Wash with plenty of water/…
- Collect spillage.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Bromomethane in the GHS label constructor →
07 · Health hazards
Bromomethane health hazards and exposure limits
Bromomethane hazard summary
Bromomethane is a manufactured chemical. It also occurs naturally in small amounts in the ocean where it is formed, probably by algae and kelp. It is a colorless, nonflammable gas with no distinct smell. Other names for bromomethane are methyl bromide, mono-bromomethane, and methyl fume. Trade names include Embafume and Terabol. Bromomethane is used to kill a variety of pests including rats, insects, and fungi. It is also used to make other chemicals or as a solvent to get oil out of nuts, seeds, and wool.
Source: Agency for Toxic Substances and Disease Registry (ATSDR)
Bromomethane carcinogenicity classification
Under the conditions of these 2-year inhalation studies, methyl bromide caused degenerative changes in the cerebellum and cerebrum, myocardial degeneration and cardiomyopathy, sternal dysplasia, and olfactory epithelial necrosis and metaplasia. Toxic effects persisted although exposure to methyl bromide in the 100 ppm group terminated after 20 weeks. There was no evidence of carcinogenic activity of methyl bromide in male or female B6C3F1 mice exposed to 10, 33, or 100 ppm.
Source: US National Toxicology Program · TR-385: Toxicology and Carcinogenesis Studies of Methyl Bromide (CASRN 74-83-9) in B6C3F1 Mice (Inhalation Studies) (1992 )
Evaluation: There is inadequate evidence in humans for the carcinogenicity of methyl bromide. There is limited evidence in experimental animals for the carcinogenicity of methyl bromide. Overall evaluation: Methyl bromide is not classifiable as to its carcinogenicity in humans (Group 3).
Source: Hazardous Substances Data Bank (HSDB)
An IARC group and a CLP classification answer different questions. IARC judges whether the evidence for cancer in humans is strong enough; CLP Annex VI is the legally binding EU classification. A substance can carry one and not the other.
Bromomethane occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 20 ppm (80 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| PEL | C 20 ppm (80 mg/m3) [skin] See Appendix G | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | Ca See Appendix A | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 250 ppm ; A potential occupational carcinogen. (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 250.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| IDLH | NIOSH considers methyl bromide to be a potential occupational carcinogen. | Hazardous Substances Data Bank (HSDB) |
These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.
08 · Physical and chemical properties
Bromomethane properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
Bromomethane boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 3.4 °C (38.1 °F) | HSDB | |
| 3.33 °C (38 °F) | NIOSH | ||
| 3.56 °C (38.4 °F) | at 760 mmHg | CAMEO |
Bromomethane melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -93.7 °C (-136.7 °F) | HSDB | |
| -93.89 °C (-137 °F) | NIOSH | ||
| -93.33 °C (-136 °F) | CAMEO |
Bromomethane density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.6755 g/cm³ | at 20 °C | HSDB |
| 0.004 g/cm³ | at 0 °C | HSDB |
Bromomethane solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | In water, 18.5 g/L at 20 °C | at 20 °C | HSDB |
| In water, 15,200 mg/L at 25 °C | at 25 °C | HSDB | |
| In water, 13.4 g/L at 25 °C | at 25 °C | HSDB |
Bromomethane vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 1444 mmHg | NIOSH | |
| 14200 mmHg | at 20 °C | HSDB | |
| 1620 mmHg | at 25 °C | HSDB |
Bromomethane flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 194 °C (381.2 °F) | Open cup vs closed cup not specified | HSDB |
| 194 °C (381.2 °F) | ICSC | ||
| NA (Gas) | NIOSH |
Bromomethane autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 537 °C (998.6 °F) | HSDB | |
| 537.22 °C (999 °F) | CAMEO |
Bromomethane lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 10 % by volume | HSDB | |
| 13.5 % by volume | HSDB |
Bromomethane upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 16 % by volume | HSDB | |
| 14.5 % by volume | HSDB |
Bromomethane vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 3.27 (air = 1) | CAMEO | |
| 3.3 (air = 1) | ICSC | ||
| 3.27 (air = 1) | at 20 °C | HSDB |
Bromomethane odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | In mg/cu m: odor low 80; odor high 4,000 | HSDB | |
| Low threshold= 80 mg/cu m, High threshold= 4000 mg/cu m | HSDB | ||
| Odor Threshold Low: 20.0 [ppm] | Haz-Map |
Bromomethane critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 194 °C (381.2 °F) | HSDB |
Bromomethane corrosivity
| Property | Value | Conditions | Source |
|---|---|---|---|
| Corrosivity | Corrosive to aluminum, magnesium & their alloys | HSDB | |
| In presence of moisture, corrosive to tin, zinc, & other alloys. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Bromomethane fire and explosion behaviour
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
Bromomethane fire potential
Not ordinarily combustible except in the presence of high heat or strong oxidizers.
Source: Hazardous Substances Data Bank (HSDB)
Corrosivity
When dry (<100 ppm water), methyl bromide is inert toward most materials of construction. Aluminum, magnesium, zinc, and alloys of these metals should not be used because under some conditions, dangerous pyrophoric Grignard-type compounds may be formed. ... Nylon and polyvinyl chloride should be avoided for handling methyl bromide.
Source: HSDB
10 · Handling and storage
Bromomethane storage and handling
Bromomethane safe storage
Fireproof if in building. Separated from strong oxidants, aluminium and cylinders containing oxygen. Cool. Ventilation along the floor.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Bromomethane storage conditions
Poison gas. Color Code-Blue: Health Hazard/ Poison: Store in a secure poison location. Prior to working with this chemical you should be trained on its proper handling and storage. Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Store in well-ventilated area away from direct sunlight. Maintain temperature below 40 °C; avoid heat sources. Protect against physical damage. A regulated, marked area should be established where this chemical is handled, used, or stored in compliance with OSHA Standard 1910.1045.
Source: Hazardous Substances Data Bank (HSDB)
Bromomethane incompatible materials
Incompatible materials: Strong oxidizing agents, Plastics, Rubber, Aluminum, Strong bases, and its alloys, Alkali metals, Zinc.
Source: Hazardous Substances Data Bank (HSDB)
Bromomethane reactivity
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].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Bromomethane in the storage compatibility matrix →
11 · Questions
Bromomethane — frequently asked questions
What is the CAS number of Bromomethane?
The CAS number of Bromomethane is 74-83-9. Its EC number is 200-813-2.
What is the chemical formula of Bromomethane?
The molecular formula of Bromomethane is CH3Br and its molecular weight is 94.94 g/mol.
What does a Bromomethane label have to show?
Under CLP Annex VI the label for Bromomethane carries the pictograms Gas cylinder, Skull and crossbones, Health hazard and Environment and the signal word is Danger.
Is Bromomethane flammable?
CLP Annex VI assigns Bromomethane no flammability hazard class. That is not a statement that it cannot burn: the harmonised list only records the hazards that were assessed for it. The flash point reported for it is 194 °C (381.2 °F), Open cup vs closed cup not specified (HSDB).
Is Bromomethane a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Bromomethane. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health. IARC places it in Group 3: not classifiable as to its carcinogenicity to humans.
What is the exposure limit for Bromomethane?
The US occupational exposure limit reported for Bromomethane is 20 ppm (80 mg/m³) (Occupational Safety and Health Administration (OSHA)). Limits differ by country: the EU sets its own indicative and binding values, and the figure that applies at a given workplace is the one in the local regulation.
What is the boiling point of Bromomethane?
The boiling point reported for Bromomethane is 3.4 °C (38.1 °F) (HSDB).
What is the melting point of Bromomethane?
The melting point reported for Bromomethane is -93.7 °C (-136.7 °F) (HSDB).
How should Bromomethane be stored?
Poison gas. Color Code-Blue: Health Hazard/ Poison: Store in a secure poison location. Prior to working with this chemical you should be trained on its proper handling and storage. Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Store in well-ventilated area away from direct sunlight. Maintain temperature below 40 °C; avoid heat sources. Protect against physical damage. A regulated, marked area should be established where this chemical is handled, used, or stored in compliance with OSHA Standard 1910.1045. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Bromomethane
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