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Bromomethane
IUPAC name Bromomethane
Other names Methyl bromide, Monobromomethane, Methyl fume, Halon 1001, Curafume, Embafume, R-40 B1, UN 1062
Identifiers
CAS number [74-83-9]
PubChem 6323
EINECS number 200-813-2
RTECS number PA4900000
SMILES CBr
InChI 1/CH3Br/c1-2/h1H3
Properties
Molecular formula CH3Br
Molar mass 94. IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to PubChem is a Database of chemical Molecules The system is maintained by the National Center for Biotechnology Information (NCBI a component The EINECS number (for European Inventory of Existing Chemical Substances) is a registry number given to each Chemical substance commercially available in the Registry of Toxic Effects of Chemical Substances ( RTECS) is a Database of Toxicity information compiled from the open scientific literature without reference The IUPAC International Chemical Identifier ( InChI, pronounced "INchee" is a textual Identifier for Chemical substances designed to provide a A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 94 g/mol
Appearance Colorless gas with chloroform-like odor (at high conc. )
Density 1. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 730 g/cm³ (0°C, liquid) [1]

3. 974 g/l (20 °C, gas)
Melting point

−93. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 66 °C
Boiling point

3. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid 56 °C
Solubility in water 15. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. 22 g/l
log P 1. In the fields of organic and Medicinal chemistry, a partition (P or distribution coefficient (D is 19
Vapor pressure 1900 hPa (20 °C)
Hazards
Main hazards Toxic (T), Dangerous for the environment (N), Carc. Cat. 3
NFPA 704
1
3
0
 
R-phrases R23/24/25, R34, R36/37/38, R45, R48/20, R50, R59, R68
S-phrases (S1/2), S15, S27, S36/39, S38, S45, S59, S61
Flash point < -30 °C (liquid)
Autoignition
temperature		 535 °C
Explosive limits 8. Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium Occupational safety and health is a cross-disciplinary area concerned with protecting the Safety, Health and welfare of people engaged in The term carcinogen refers to any substance Radionuclide or radiation that is an agent directly involved in the promotion of Cancer or in the fatation of its propagation Symbolism The four divisions are typically color-coded with blue indicating level of Health Hazard, red indicating R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. The flash point of a flammable liquid is the lowest Temperature at which it can form an ignitable mixture in air The autoignition temperature or kindling point of a substance is the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external 6 - 20 %
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

The chemical compound bromomethane, commonly known as methyl bromide, is an organic halogen compound with formula CH3Br. In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly A chemical compound is a substance consisting of two or more different elements chemically bonded together in a fixed proportion by Mass. An organic compound is any member of a large class of Chemical compounds whose Molecules contain Carbon. Abundance Owing to their high Reactivity, the halogens are found in the environment only in compounds or as Ions Halide ions and oxoanions A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 It is a colorless, nonflammable gas with no distinctive smell. Its chemical properties are quite similar to those of chloromethane. Chloromethane, also called Methyl chloride, R-40 or HCC 40 is a Chemical compound of the group of Organic compounds called Haloalkanes. It is a recognized ozone-depleting chemical. Ozone depletion describes two distinct but related observations a slow steady decline of about 4 percent per decade in the total amount of Ozone in Earth's It was used extensively as a pesticide until being phased out by most countries in the early 2000s. A pesticide is a substance or mixture of substances used to kill a pest. Some use, notably in the United States, continues. Trade names for bromomethane include Embafume and Terabol.

Contents

Occurrence and manufacture

Bromomethane originates from both natural and human sources. It occurs naturally in the ocean, where it is found in some species of kelp. An ocean (from Greek, ''Okeanos'' (Oceanus) is a major body of saline water, and a principal component of the Hydrosphere. Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales It is also produced in small quantities by certain terrestrial plants, such as members of the Brassicaceae family. Brassicaceae or Cruciferae, also known as the crucifers, the mustard family or cabbage family is a family (the third lowest primary It is manufactured for agricultural and industrial use by reacting methanol with hydrobromic acid. Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naphtha or wood spirits, is a Chemical compound Hydrobromic Acid is formed by dissolving the diatomic molecule Hydrogen bromide in water

Uses

Until its production and use was curtailed by the Montreal Protocol, it was widely used as a soil sterilant, mainly for production of seed but also for some crops such as strawberries. For other similarly-named agreements see Montreal Convention (disambiguation. Soil, often typeset as SOiL, is a four piece rock band from Chicago Illinois United States founded by Shaun Glass Tom Schofield Tim King and Adam Zadel Sterilization (or sterilisation, see spelling differences) refers to any process that effectively kills or eliminates transmissible agents (such as Fungi A seed (in some plants referred to as a kernel) is a small embryonic Plant enclosed in a covering called the seed coat usually with some stored Garden strawberries are a common variety of strawberry cultivated worldwide In commercial large-scale monoculture seed production, unlike crop production, it is of vital importance to avoid contaminating the crop with off-type seed of the same species. The Green Revolution refers to the transformation of Agriculture that began in 1945 at the request of the Mexican government to establish an agricultural research station to Therefore, selective herbicides cannot be used. A herbicide is used to kill unwanted Plants Selective herbicides kill specific targets while leaving the desired Crop relatively unharmed While bromomethane is dangerous to use, it is considerably safer and more effective than the few other soil sterilants available. Its loss to the seed industry has resulted in changes to cultural practices, with increased reliance on soil steam sterilization, mechanical rogueing, and fallow seasons. Soil steam sterilization is a Farming technique that sterilizes Soil with Steam in open fields or greenhouses

Bromomethane was also used as a general-purpose fumigant to kill a variety of pests including rats and insects. Fumigation is a method of Pest control that completely fills an area with gaseous Pesticides to suffocate or poison the pests within Rats are various medium sized long-tailed Rodents of the superfamily Muroidea Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described Bromomethane has poor fungicidal properties. (Bromomethane is the preferred fumigant for ISPM number 15, regulations when exporting wooden packaging to certain countries). It is also a precursor in the manufacture of other chemicals as a methylation agent, and has been used as a solvent to extract oil from seeds and wool. Methylation is a term used in the chemical sciences to denote the attachment or substitution of a methyl group on various substrates. A solvent is a liquid or gas that dissolves a solid liquid or gaseous Solute, resulting in a Solution. Liquid-liquid extraction, also known as solvent extraction and partitioning, is a method to separate compounds based on their relative solubilities in two An oil is a substance that is in a viscous Liquid state ( "oily") at ambient temperatures or slightly warmer and is A seed (in some plants referred to as a kernel) is a small embryonic Plant enclosed in a covering called the seed coat usually with some stored Wool is the fiber derived from the specialized skin cells called follicles of animals in the Caprinae family principally sheep, but the hair of certain species

While the Montreal Protocol has severely restricted the use of bromomethane internationally, the United States has successfully pushed for critical-use exemptions of the chemical. For other similarly-named agreements see Montreal Convention (disambiguation. In 2004, the most recent year with available data, over 7 million pounds of bromomethane were applied to California fields, according to pesticide use statistics compiled by the California Department of Pesticide Regulation.

Ozone depletion

Bromomethane is on the list of banned ozone-depleting substances of the Montreal Protocol. Ozone depletion describes two distinct but related observations a slow steady decline of about 4 percent per decade in the total amount of Ozone in Earth's For other similarly-named agreements see Montreal Convention (disambiguation. Because bromine is 60 times[1] more destructive to ozone than chlorine, even small amounts of bromomethane cause considerable damage to the ozone layer. OZONE is an object oriented Operating system written in the C programming language. Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and The photochemical mechanisms that give rise to the ozone layer were worked out by the British physicist Sidney Chapman in 1930 In 2005 and 2006, however, it was granted a critical use exemption under the Montreal Protocol.

Controversy

Bromomethane is used to prepare golf courses and sod for golf courses and elsewhere, particularly to control Bermuda grass. The Montreal Protocol stipulates that bromomethane use be phased out. For other similarly-named agreements see Montreal Convention (disambiguation. The Bush Administration has adopted exceptions "to prevent market disruptions". The Presidency of George W Bush began on his inauguration on January 20, 2001 as the 43rd and current President of the United States of America The most recent set of 'critical use' exemptions in the US include use of Bromomethane for tomato, strawberry, and ornamental shrub growers, and fumigation of ham/pork products.

Health effects

If inhaled in high concentration for a short period, it produces headaches, dizziness, nausea, vomiting and weakness; this may be followed by mental excitement, convulsions and even acute mania. An epileptic seizure is caused by excessive and/or hypersynchronous electrical Neuronal activity and is usually self-limiting Mania (from Greek μανία and that from μαίνομαι - mainomai, "to rage to be furious" is a severe medical condition More prolonged inhalation of lower concentrations may cause bronchitis and pneumonia. Bronchitis is an Inflammation of the Bronchi. More specifically it may refer to Acute bronchitis, caused by viruses or bacteria and lasting Pneumonia is an inflammatory illness of the Lung. Frequently it is described as lung Parenchyma / alveolar inflammation and abnormal [2]

The liquid burns the skin, producing itching and reddening, then blisters several hours after contact. Both liquid and vapour severely damage the eyes. [2]

Exposure levels leading to death vary from 1,600 to 60,000 ppm, depending on the duration of exposure.

The respiratory, kidney, and neurologic effects are of the greatest concern to people. No cases of severe effects on the nervous system from long-term exposure to low levels have been noted in people, but studies in rabbits and monkeys have shown moderate to severe injury. The nervous system is a Network of specialized cells that communicate information about an animal's surroundings and itself Rabbits are small Mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world A monkey is any member of either the New World monkeys or Old World monkeys two of the three groupings of Simian Primates the third group being

Sources and sinks

Sources of CH3Br include oceanic production, biomass burning, leaded fuel combustion, and fumigation of soils, durable goods, perishables, and structures. Biomass refers to living and recently dead Biological material that can be used as fuel or for industrial production Fumigation is a method of Pest control that completely fills an area with gaseous Pesticides to suffocate or poison the pests within Sinks include photochemical decomposition in the atmosphere (reaction with hydroxyl radicals (OH) and photolysis at higher altitudes), loss to soils, chemical and biological degradation in the ocean, and uptake by green plants. Photochemistry, a sub-discipline of Chemistry, is the study of the interactions between Atoms, small Molecules, and light (or Electromagnetic radiation Hydroxyl in Chemistry stands for a molecule consisting of an Oxygen atom and a Hydrogen atom connected by a Covalent bond. In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell Photodissociation, photolysis, or photodecomposition is a Chemical reaction in which a Chemical compound is broken down by Photons

See also

References

  1. ^ Merck Index, 11th Edition, 5951. The haloalkanes (also known as halogenoalkanes or alkyl halides) are a group of Chemical compounds consisting of Alkanes such as Methane Halomethane compounds are molecules of Methane ( C[[hydrogen H]]4 with one or more of the Hydrogen atoms replaced with Halogen atoms Fluoromethane, also known as methyl fluoride, Freon 41, Halocarbon-41 and HFC-41, is a non-toxic liquefiable and flammable Chloromethane, also called Methyl chloride, R-40 or HCC 40 is a Chemical compound of the group of Organic compounds called Haloalkanes. Iodomethane, commonly called Methyl iodide and commonly abbreviated "MeI" is the Chemical compound with the formula CH3I Dibromomethane or methylene bromide, or methylene dibromide is a Halomethane. Bromoform (CHBr3 is a pale yellowish liquid with a sweet odor similar to chloroform a Halomethane or haloform Tetrabromomethane, CBr4 also known as carbon tetrabromide, is a Carbon Bromide.
  2. ^ a b Muir, GD (ed. ) 1971, Hazards in the Chemical Laboratory, The Royal Institute of Chemistry, London.

External links

Dictionary

bromomethane

-noun

  1. (organic chemistry) The brominated hydrocarbon CH3Br once used as a soil sterilant
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