Brommethan Chemische Eigenschaften,Einsatz,Produktion Methoden

ERSCHEINUNGSBILD

GERUCHLOSES UND FARBLOSES, KOMPRIMIERTES FLüSSIGGAS.

PHYSIKALISCHE GEFAHREN

Das Gas ist schwerer als Luft.

CHEMISCHE GEFAHREN

Zersetzung beim Erhitzen und Verbrennen unter Bildung giftiger und ?tzender Rauche mit Bromwasserstoff, Brom und Acetylbromid. Reagiert mit starken Oxidationsmitteln. Greift viele Metalle in Gegenwart von Wasser an. Greift Aluminium, Zink und Magnesium an unter Bildung selbstentzündlicher Verbindungen. Feuer- und Explosionsgefahr.

ARBEITSPLATZGRENZWERTE

TLV: 1 ppm (als TWA); Hautresorption; Krebskategorie A4 (nicht klassifizierbar als krebserzeugend für den Menschen); (ACGIH 2005).
MAK: Hautresorption; Krebserzeugend Kategorie 3B; (DFG 2005).

AUFNAHMEWEGE

Aufnahme in den K?rper durch Inhalation und über die Haut, auch als Dampf!

INHALATIONSGEFAHREN

Eine gesundheitssch?dliche Konzentration des Gases in der Luft wird beim Entweichen aus dem Beh?lter sehr schnell erreicht.

WIRKUNGEN BEI KURZZEITEXPOSITION

WIRKUNGEN BEI KURZZEITEXPOSITION:
Das Gas reizt die Augen, die Haut und die Atmungsorgane. Inhalation des Gases kann zu Lungen?dem führen (s. Anm.). Schnelle Verdampfung der Flüssigkeit kann zu Erfrierungen führen. M?glich sind Auswirkungen auf Zentralnervensystem, Nieren und Lunge. Exposition gegenüber hohen Konzentrationen kann zum Tod führen. Die Auswirkungen treten u.U. verz?gert ein.

WIRKUNGEN NACH WIEDERHOLTER ODER LANGZEITEXPOSITION

M?glich sind Auswirkungen auf Nervensystem, Nieren, Herz, Leber und Lunge.

LECKAGE

Gefahrenbereich verlassen! Fachmann zu Rate ziehen! Belüftung. Wasserstrahl NIEMALS auf die Flüssigkeit richten. Pers?nliche Schutzausrüstung: Vollschutzanzug mit umgebungsluftunabh?ngigem Atemschutzger?t.

R-S?tze Betriebsanweisung:

R23/25:Giftig beim Einatmen und Verschlucken.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
R48/20:Gesundheitssch?dlich: Gefahr ernster Gesundheitssch?den bei l?ngerer Exposition durch Einatmen.
R50:Sehr giftig für Wasserorganismen.
R59:Gef?hrlich für die Ozonschicht.
R68:Irreversibler Schaden m?glich.
R38:Reizt die Haut.
R20/22:Gesundheitssch?dlich beim Einatmen und Verschlucken.
R11:Leichtentzündlich.
R67:D?mpfe k?nnen Schl?frigkeit und Benommenheit verursachen.
R66:Wiederholter Kontakt kann zu spr?der oder rissiger Haut führen.
R19:Kann explosionsf?hige Peroxide bilden.
R12:Hochentzündlich.

S-S?tze Betriebsanweisung:

S15:Vor Hitze schützen.
S27:Beschmutzte, getr?nkte Kleidung sofort ausziehen.
S36/39:Bei der Arbeit geeignete Schutzkleidung und Schutzbrille/Gesichtsschutz tragen.
S38:Bei unzureichender Belüftung Atemschutzger?t anlegen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn m?glich, dieses Etikett vorzeigen).
S59:Informationen zur Wiederverwendung/Wiederverwertung beim Hersteller/Lieferanten erfragen.
S61:Freisetzung in die Umwelt vermeiden. Besondere Anweisungen einholen/Sicherheitsdatenblatt zu Rate ziehen.
S36/37:Bei der Arbeit geeignete Schutzhandschuhe und Schutzkleidung tragen.
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S24:Berührung mit der Haut vermeiden.
S16:Von Zündquellen fernhalten - Nicht rauchen.
S7:Beh?lter dicht geschlossen halten.

Aussehen Eigenschaften

CH3Br; Methylbromid, Brommethyl; farbloses, süßlich, chloroformartig riechendes Gas (in niedrigen Konzentrationen praktisch geruchlos).

Gefahren für Mensch und Umwelt

Mit Alkali- und Erdalkalimetallen, Leichtmetallen und Zink sind starke exotherme Reaktionen mit Entzündungsgefahr zu erwarten.
Methylbromid ist einer der toxischsten und heimtückischsten Halogenkohlenwasserstoffe. Die Inhalation hoher Konzentrationen, die nicht sofort zu Narkose und Atemstillstand führt, erzeugt nach mehrstündiger Latenz ein Lungenödem, oft mit nach Tagen folgender schwerer Lungenentzündung. Eine weitere Folge akuter wie auch lang anhaltender wiederholter Einwirkungen geringer Dosen sind Veränderungen im Nervensystem. Sie bewirken anfangs Kopfschmerzen und Übelkeit, später EErregung und Tremor, Tobsucht und epileptiforme Krämpfe. Die Flüssigkeit erzeugt auf der Haut schwere Entzündungen. Die systemischen Schäden sind auch als Folge einer Hautresorption möglich.
Stark wassergefährdender Stoff.

Schutzma?nahmen und Verhaltensregeln

Unbedingt im Abzug arbeiten und für geschlossene Apparaturen sorgen. Behälter kühl und geschlossen lagern. In geringen Konzentrationen keine Geruchswarnwirkung! Berührung mit Augen, Haut und Kleidung unbedingt vermeiden.
Schutzhandschuhe aus Gummi (nur kurzzeitig als Spritzschutz).

Verhalten im Gefahrfall

Nach Gasaustritt betroffene Räume sofort räumen. Umluftunabhängiges Atemschutzgerät anlegen.
Im Brandfall Behälter mit Wasser kühlen!

Erste Hilfe

Nach Hautkontakt: Mit viel Wasser abspülen. Abtupfen mit Polyethylenglykol 400. Arzt aufsuchen.
Nach Augenkontakt: Nach Augenkontakt bei geöffnentem Lidspalt mindestens 10 Minuten mit Wasser spülen. Sofort Augenarzt konsultieren.
Nach Einatmen: Frischluft. Gegebenenfalls Atemspende. Rasche Gabe von Auxiloson-Spray. Arzt hinzuziehen.
Nach Verschlucken: Gabe von Paraffin liq., Erbrechen vermeiden. Sofort Arzt konsultieren.
Nach Kleidungskontakt: Kontaminierte Kleidung sofort ausziehen.
Ersthelfer: siehe gesonderten Anschlag

Sachgerechte Entsorgung

Kleinere Mengen Brommethan werden im Abzug vorsichtig in 10% Ammoniaklösung eingeleitet. Benutzte Gerätschaften im Abzug mit Ammoniaklösung reinigen.

Beschreibung

Methyl bromide is a colorless liquid or gas with practically no odor. It is a poisonous gas at room temperature and atmospheric pressure. At high concentrations, it has a chloroform-like odor. Detection of lower concentrations is often facilitated by a warning odorant, chloropicrin, which is added by the manufacturer.
Methyl bromide is flammable only in the range of 10 percent to 16 percent by volume in air. Its physical properties do not meet the definition of a flammable gas as defined by DOT and TC. The onset of thermal decomposition occurs at approximately 752°F (400°C).

Chemische Eigenschaften

Methyl bromide is a colorless gas with a chloroform-like odor at high concentrations. A liquid below 3.3C. Shipped as a liquefied compressed gas.

Physikalische Eigenschaften

Colorless liquid or gas with an odor similar to chloroform at high concentrations. Ruth (1986) reported odor threshold concentrations ranging from 80 to 4,000 mg/m³.

Occurrence

An organic compound, present in the atmosphere as the result of both natural (oceanic production) and anthropogenic (use as a soil fumigant) sources; this compound is the largest single source of bromine to the stratosphere, with a tropospheric mixing ratio of about 10 parts per trillion (by volume).

Verwenden

Methyl bromide is used as a fumigant forpest control, for degreasing wool, and as a methylating agent. Its use as a refrigerant andin fire extinguishers is restrained because ofits health hazards.

Definition

ChEBI: A one-carbon compound in which the carbon is attached by single bonds to three bromine atoms and one hydrogen atom. It is produced naturally by marine algae.

Vorbereitung Methode

The commercial manufacture of methyl bromide is based on the reaction of hydrogen bromide with methanol. The hydrogen bromide used could be generated in situ from bromine and a reducing agent. The uses of sulfur or hydrogen sulfide as reducing agents are described, the latter process having the advantage. A new continuous process for the production of methyl bromide from methanol and aqueous HBr in the presence of a silica supported heteropolyacid catalyst has recently been described. Methyl bromide can also be coproduced with other organic bromine compounds by the reaction of the methanol solvent with hydrogen bromide formed as a by-product. The processes include coproduction of methyl bromide with bromostyrenes, tribromophenol, potassium and sodium bromide, and especially tetrabromo bisphenol A.

Reaktionen

Methyl bromide is present in the atmosphere as the result of both natural (oceanic production) and anthropogenic (use as a soil fumigant) sources; this compound is the largest single source of bromine to the stratosphere, with a tropospheric mixing ratio of about 10 parts per trillion (by volume). Methyl bromide reacts with several nucleophiles and is a useful methylation agent for the preparation of ethers, sulfides, amines, etc. Tertiary amines are methylated by methyl bromide to form quaternary ammonium bromides. The reactivity of methyl bromide is summarized in Figure 1.

Allgemeine Beschreibung

Colorless highly toxic volatile liquid or a gas. Boiling point 3.56°C (38.41°F). Usually odorless, but has a sweetish chloroform-like odor at high concentrations. Used as an insecticide, a rodenticide, a fumigant, a nematocide, a chemical intermediate and as a fire extinguishing agent.

Air & Water Reaktionen

Nonflammable over a wide range of concentrations in air. Slightly soluble in water (about 1.75 g/100 mL of solution at 20° C). Reacts slowly with water to give methyl alcohol and hydrobromic acid. [K-O Vol. 4].

Reaktivit?t anzeigen

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].

Hazard

Toxic by ingestion, inhalation, and skin absorption; strong irritant to skin and upper respiratory tract. Questionable carcinogen.

Health Hazard

Methyl bromide is a dangerous cumulative poison with delayed symptoms of central nervous system intoxication that may appear as long as several months after exposure. High concentrations can produce fatal pulmonary edema. Chronic exposure can cause central nervous system depression and kidney injury. It may cause severe and permanent brain damage. Severe neurological signs may appear when there is a sudden exposure to high concentrations following continuous slight exposure. Methyl bromide has practically no odor or irritating effects and therefore no warning, even at hazardous concentrations.

Brandgefahr

When heated to decomposition, Methyl bromide emits toxic fumes of bromides. Hazardous polymerization may not occur.

Landwirtschaftliche Anwendung

Fumigant, Herbicide, Insecticide, Nematicide: The primary use of methyl bromide is as an insect fumigant to control insects, nematodes, weeds and pathogens in more than 100 crops and for soil, grain storage, warehouses, mills, ships, etc. Use of methyl bromide in the U.S. will be phased out under the requirements of the Montreal Protocol, with some exemptions. Methyl bromide is also used as a chemical intermediate and a methylating agent, a refrigerant, a herbicide, a fire-extinguishing agent, a low-boiling solvent in aniline dye manufacture, for degreasing wool, for extracting oils from nuts, seeds, and flowers, and in ionization chambers. It is used as an intermediate in the manufacture of many drugs. A U.S. EPA restricted Use Pesticide (RUP), NO INERT. Still actively registered for use in the U.S. (2013). As of March 18, 2005, the use of methyl bromide in the EU was banned for most purposes, including quarantine and pre-shipment fumigations.Registered for use in the U.S.

Handelsname

BROM-O-GAS®; BROM-OSOL ®; DAWSON® 100; DOWFUME®; EDCO®; EMBAFUME®; HALON 1001®; ISCOBROME®; KAYAFUME®; MATABROM®; METHO-GAS®; M-B-C FUMIGANT®; R 40B1®; ROTOX®; TERABOL®; TERR-O-GAS®; ZYTOX®

Materials Uses

Dry methyl bromide is inert and noncorrosive in the presence of most structural metals. However, in the presence of impurities such as alcohols and water, reactions will take place on zinc, tin, and iron surfaces. Aluminum and its alloys should not be used for methyl bromide service because of the formation of trimethyl aluminum, which is pyrophoric.

m?gliche Exposition

Methyl bromide is used in fire extinguishers; as a fumigant in pest control and as a methylation agent in industry as an insect fumigant for soil, grain, warehouses, mills, ships, etc. It is also used as a chemical intermediate and a methylating agent; a refrigerant; a herbicide; a low-boiling solvent in aniline dye manufacture; for degreasing wool; for extracting oils from nuts, seeds, and flowers; and in ionization chambers. It is used as an intermediate in the manufacture of many drugs.

Carcinogenicity

Data on the carcinogenicity of bromomethane for oral exposure are lacking, but oral exposure is unlikely due to the volatility of bromomethane. A 1-year study in dogs consuming bromomethane-exposed food found no evidence of carcinogenicity. Data on carcinogenicity in humans following inhalation exposure in humans are not available. Animal inhalation studies exist but do not demonstrate evidence of bromomethane-induced carcinogenic changes. They include studies in F344 and Wistar rats, and in B6C3F1 and Crj:BDF1. The EPA descriptor for cancer is “inadequate information to assess the carcinogenic potential of bromomethane in humans.” Specifically, IRIS states: “Inadequate human and animal data: a single mortality study from which direct exposure associations could not be deduced and studies in several animal species with too few animals, too brief exposure or observation time for adequate power.” Bromomethane has shown genotoxicity. NAS reported that although methyl bromide is genotoxic without metabolic activation and has been shown to alkylate DNA in different organs in in vivo studies, there is no clear evidence of oncogenicity under experimental conditions used in the chronic inhalation studies with rat and mice.

Environmental Fate

Photolytic. When methyl bromide and bromine gas (concentration = 3%) was irradiated at 1850 ?, methane was produced (Kobrinsky and Martin, 1968).
Chemical/Physical. Methyl bromide hydrolyzes in water forming methanol and hydrobromic acid. The estimated hydrolysis half-life in water at 25°C and pH 7 is 20 days (Mabey and Mill, 1978). Forms a voluminous crystalline hydrate at 0–5°C (Keith and Walters, 1992).
When methyl bromide was heated to 550°C in the absence of oxygen, methane, hydrogen, bromine, ethyl bromide, anthracene, pyrene and free radicals were produced (Chaigneau et al., 1966).
Emits toxic bromide fumes when heated to decomposition (Lewis, 1990).

Stoffwechselwegen

Methyl bromide degrades in aqueous and soil environments mainly via dehalogenation to yield bromide ions with the incorporation of the methyl carbon moiety into polar natural components.

Lager

Methyl bromide (Bromomethane) should be kept stored in sealed containers to keep it from evaporating.

Versand/Shipping

UN1062 Methyl bromide, Hazard Class: 2.3; Labels: 2.3-Poisonous gas, Inhalation Hazard Zone C. Cylinders must be transported in a secure upright position, in a well-ventilated truck. Protect cylinder and labels from physical damage. The owner of the compressed gas cylinder is the only entity allowed by federal law (49CFR) to transport and refill them. It is a violation of transportation regulations to refill compressed gas cylinders without the express written permission of the owner

l?uterung methode

Purify it by bubbling through conc H2SO4, followed by passage through a tube containing glass beads coated with P2O5. Also purify it by distillation from AlBr3 at -80o, by passage through a tower of KOH pellets and by partial condensation. [Beilstein 1 IV 68.]

Inkompatibilit?ten

Attacks aluminum to form spontaneously flammable aluminum trimethyl. Incompatible with strong oxidizers, aluminum, dimethylsulfoxide, ethylene oxide; water. Attacks zinc, magnesium, alkali metals and their alloys. Attacks some rubbers and coatings. 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.

Waste disposal

Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform to EPA regulations governing storage, transportation, treatment, and waste disposal. A poisonous gas. Must be handled by experts: the recommended disposal procedure is to spray the gas into the fire box of an incinerator equipped with an afterburner and scrubber (alkali).

Vorsichtsma?nahmen

Occupational workers should use appropriate ventilation during production and formulation of bromomethane at the workplace. The ventilation must be suffi cient to maintain the levels of bromomethane below the prescribed OEL. Local exhaust ventilation at source or vapor extraction may also be used. Gloves or rubber boots should not be used as the liquid or concentrated vapor may be trapped inside them

Brommethan Upstream-Materialien And Downstream Produkte

Upstream-Materialien

Downstream Produkte

74-83-9(Brommethan)Verwandte Suche:

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• caswellno555
• Curafume
• Dawson 100
• dawson100
• Detia gas ex-M
• detiagasex-m
• Dowfume
• Dowfume mc-2
• Dowfume mc-33
• dowfumemc-2
• dowfumemc-2fumigant
• dowfumemc-2r
• dowfumemc-2soilfumigant
• dowfumemc-33
• drexelplantbedgas
• epapesticidechemicalcode053201
• F40B1
• Fumigant-1
• fumigant-1(obs.)
• halon1001
• halon-1001
• Haltox
• Iscobrome
• Kayafume
• mbc-33soilfumigant
• m-b-cfumigant
• mbcsoilfumigant
• m-b-r98
• MBX
• Merth-O-gas
• Metafume
• methane,bromo
• Methogas
• meth-o-gas
• Methybrom
• methylbromide(bromomethane)
• methylbromideandnonflammable,nonliquefiedcompressedgasmixture
• methylbromiderodentfumigant(withchloropicrin)
• methylfume
• Metylu bromek
• metylubromek
• terr-o-cideii
• terr-o-gas
• Terr-O-gas 100
• Terr-O-gas 67
• terr-o-gas100
• terr-o-gas67
• tri-brom
• Zytox
• THIOGLYCOLIC ACID SODIUM SALT REAGENT GR
• ai3-01916
• Brom-methan
• Brom-O-gas
• bromo-gas
• brom-o-gasmethylbromidesoilfumigant
• Brom-O-gaz
• Bromometano
• bromo-methan