Benzylalkohol Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
FARBLOSE FLüSSIGKEIT MIT CHARAKTERISTISCHEM GERUCH.
CHEMISCHE GEFAHREN
Reagiert mit starken Oxidationsmitteln. Greift einige Kunststoffarten an. Beim Verbrennen Bildung giftiger Gase mit Kohlenmonoxid.
ARBEITSPLATZGRENZWERTE
TLV nicht festgelegt (ACGIH 2005).
MAK: IIb (nicht festgelegt, aber Informationen vorhanden) (DFG 2005).
AUFNAHMEWEGE
Aufnahme in den Körper durch Inhalation der Dämpfe und durch Verschlucken.
INHALATIONSGEFAHREN
Nur ungenügende Angaben vorhanden über die Geschwindigkeit, mit der eine gesundheitsschädliche Konzentration in der Luft beim Verdampfen bei 20°C erreicht wird.
WIRKUNGEN BEI KURZZEITEXPOSITION
WIRKUNGEN BEI KURZZEITEXPOSITION: Das Aerosol reizt die Augen und die Haut. Möglich sind Auswirkungen auf das Nervensystem.
WIRKUNGEN NACH WIEDERHOLTER ODER LANGZEITEXPOSITION
Wiederholter oder andauernder Kontakt kann zu Hautsensibilisierung führen.
LECKAGE
Ausgelaufene Flüssigkeit in abdichtbaren Behältern sammeln. Reste mit Sand oder inertem Absorptionsmittel aufnehmen und an einen sicheren Ort bringen. Persönliche Schutzausrüstung: Atemschutzfilter für organische Gase und Dämpfe.
R-Sätze Betriebsanweisung:
R20/22:Gesundheitsschädlich beim Einatmen und Verschlucken.
R63:Kann das Kind im Mutterleib möglicherweise schädigen.
R43:Sensibilisierung durch Hautkontakt möglich.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
R23/24/25:Giftig beim Einatmen, Verschlucken und Berührung mit der Haut.
R45:Kann Krebs erzeugen.
R40:Verdacht auf krebserzeugende Wirkung.
S-Sätze Betriebsanweisung:
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S36/37:Bei der Arbeit geeignete Schutzhandschuhe und Schutzkleidung tragen.
S24/25:Berührung mit den Augen und der Haut vermeiden.
S23:Gas/Rauch/Dampf/Aerosol nicht einatmen(geeignete Bezeichnung(en) vom Hersteller anzugeben).
S53:Exposition vermeiden - vor Gebrauch besondere Anweisungen einholen.
Aussehen Eigenschaften
C7H8O; Phenylcarbinol. Farblose Flüssigkeit mit charakteristischem Geruch.
Gefahren für Mensch und Umwelt
Gesundheitsschädlich beim Einatmen und Verschlucken.
Resorption führt zu ZNS-Störungen.
Nicht mit Oxidationsmitteln, Nichtmetallhalogeniden, Polymerisationsinitiatoren oder konz. Schwefelsäure in Berührung bringen.
LD
50 (oral, Mensch): 500 mg/kg
Schutzmaßnahmen und Verhaltensregeln
Geeignete Schutzhandschuhe als kurzzeitiger Spritzschutz.
Verhalten im Gefahrfall
Dämpfe nicht einatmen.
Mit flüssigkeitsbindendem Material, z.B. Rench Rapid aufnehmen. Der Entsorgung zuführen. Nachreinigen.
Pulver, Schaum.
Brennbar. Dämpfe schwerer als Luft. Mit Luft Bildung explosionsfähiger Gemische möglich. Im Brandfall können gefährliche Dämpfe entstehen.
Erste Hilfe
Nach Hautkontakt: Mit reichlich Wasser abwaschen.
Nach Augenkontakt: Mit reichlich Wasser bei geöffnetem Lidspalt mindestens 10 Minuten ausspülen. Sofort Augenarzt hinzuziehen.
Nach Einatmen: Frischluft.
Nach Verschlucken: Kein Erbrechen auslösen (Aspirationsgefahr!). Sofort Arzt hinzuziehen.
Nach Kleidungskontakt: Kontaminierte Kleidung entfernen.
Ersthelfer: siehe gesonderten Anschlag
Sachgerechte Entsorgung
Als halogenfreie, organische Lösemittelabfälle.
Beschreibung
Benzyl alcohol is a component catalyst for epoxy
resins. It is also contained in the color developer C-22.
Chemische Eigenschaften
Benzyl alcohol occurs in many essential oils and foods. It is a colorless liquid with a weak, slightly sweet odor. Benzyl alcohol can be oxidized to benzaldehyde, for example, with nitric acid. Dehydrogenation over a copper–magnesium oxide–pumice catalyst also leads to the aldehyde. Esterification of benzyl alcohol results in a number of important fragrance and flavor materials. Diphenylmethane is prepared by a Friedel–Crafts reaction of benzyl alcohol and benzene with aluminum chloride or concentrated sulfuric acid. By heating benzyl alcohol in the presence of strong acids or strong bases, dibenzyl ether is formed.
Physikalische Eigenschaften
Colorless, hygroscopic, air sensitive liquid with a faint, pleasant, aromatic odor. Odor threshold
concentration in water is 10 ppm (Buttery et al., 1988).
Occurrence
The free alcohol is often present in several essential oils and extracts of jasmine, tobacco, tea, neroli, copaiba,
Acacia farnesiana Willd., Acacia cavenia Hook. and Arn., Robinia pseudacacia, ylang-ylang, Pandanus odoratissimus, Michelia
champaca, Prunus laurocerasus, tuberose, orris, castoreum, violet leaves, clove buds and others. Also found in fresh apple, apricot,
mandarin peel oil, high bush blueberry, raspberry, strawberry fruit, American cranberry and cooked asparagus.
History
L
IEBIG and W
O¨HLER first prepared benzyl alcohol from bitter almond oil (benzaldehyde) in 1832. The structure of benzyl alcohol was determined in 1853 by C
ANNIZZARO. C
ANNIZZARO used the reaction named after him, in which benzaldehyde is disproportionated into benzoic acid and benzyl alcohol through the action of an alkali.
Verwenden
benzyl alcohol is a preservative against bacteria, used in concentrations of 1 to 3 percent. It can cause skin irritation.
Definition
ChEBI: Benzyl alcohol is an aromatic alcohol that consists of benzene bearing a single hydroxymethyl substituent. It has a role as a solvent, a metabolite, an antioxidant and a fragrance.
synthetische
Benzyl alcohol is prepared commercially by the distillation of benzyl chloride with potassium or sodium carbonate. It may also be prepared by the Cannizzaro reaction of benzaldehyde and potassium hydroxide.
Weltgesundheitsorganisation (WHO)
Benzyl alcohol has been used as an antimicrobial agent in
pharmaceutical preparations for many years. Parenteral administration of
preparations containing 0.9% benzyl alcohol resulted in the death of 16 neonates in
the USA in the early 1980s. Many countries subsequently warned against using
such preparations in neonates. This decision is not applicable to the use of benzyl
alcohol as a preservative in other circumstances or to its use in topical
preparations and no country has placed a total ban on the compound.
Allgemeine Beschreibung
A clear colorless liquid with a pleasant odor. Slightly denser than water. Flash point 194°F. Boiling point 401°F. Contact may irritate skin, eyes, and mucous membranes. May be slightly toxic by ingestion. Used to make other chemicals.
Air & Water Reaktionen
Slightly soluble in water.
Reaktivität anzeigen
Attacks plastics. [Handling Chemicals Safely 1980. p. 236]. Acetyl bromide reacts violently with alcohols or water [Merck 11th ed. 1989]. Mixtures of alcohols with concentrated sulfuric acid and strong hydrogen peroxide can cause explosions. Example: an explosion will occur if dimethylbenzylcarbinol is added to 90% hydrogen peroxide then acidified with concentrated sulfuric acid. Mixtures of ethyl alcohol with concentrated hydrogen peroxide form powerful explosives. Mixtures of hydrogen peroxide and 1-phenyl-2-methyl propyl alcohol tend to explode if acidified with 70% sulfuric acid [Chem. Eng. News 45(43):73 1967; J, Org. Chem. 28:1893 1963]. Alkyl hypochlorites are violently explosive. They are readily obtained by reacting hypochlorous acid and alcohols either in aqueous solution or mixed aqueous-carbon tetrachloride solutions. Chlorine plus alcohols would similarly yield alkyl hypochlorites. They decompose in the cold and explode on exposure to sunlight or heat. Tertiary hypochlorites are less unstable than secondary or primary hypochlorites [NFPA 491 M 1991]. Base-catalysed reactions of isocyanates with alcohols should be carried out in inert solvents. Such reactions in the absence of solvents often occur with explosive violence [Wischmeyer 1969].
Hazard
Highly toxic.
Health Hazard
Benzyl alcohol is a low acute toxicant witha mild irritation effect on the skin. Theirritation in 24 hours from the pure compoundwas mild on rabbit skin and moderateon pig skin. A dose of 750 μg producedsevere eye irritation in rabbits. The toxicityof benzyl alcohol is of low order,the effects varying with the species. Oralintake of high concentrations of this compoundproduced behavioral effects in rats.The symptoms progressed from somnolenceand excitement to coma. Intravenous administrationin dogs produced ataxia, dyspnea,diarrhea, and hypermotility in the animals.
Adult and neonatal mice treated withbenzyl alcohol exhibited behavioral change,including sedation, dyspnea, and loss ofmotor function. Pretreatment with pyrazoleincreased the toxicity of benzyl alcohol. Withdisulfiram the toxicity remained unchanged.The study indicated that the acute toxicitywas due to the alcohol itself andnot to bezaldehyde, its primary metabolite(McCloskey et al. 1986).
Brandgefahr
Benzyl alcohol is combustible.
Pharmazeutische Anwendungen
Benzyl alcohol is an antimicrobial preservative used in cosmetics,
foods, and a wide range of pharmaceutical formulations,
including oral and parenteral preparations, at concentrations up
to 2.0% v/v. The typical concentration used is 1% v/v, and it has
been reported to be used in protein, peptide and small molecule
products, although its frequency of use has fallen from 48 products
in 1996, 30 products in 2001, to 15 products in 2006. In
cosmetics, concentrations up to 3.0% v/v may be used as a
preservative. Concentrations of 5% v/v or more are employed as a
solubilizer, while a 10% v/v solution is used as a disinfectant.
Benzyl alcohol 10% v/v solutions also have some local anesthetic
properties, which are exploited in some parenterals, cough
products, ophthalmic solutions, ointments, and dermatological
aerosol sprays.
Although widely used as an antimicrobial preservative, benzyl
alcohol has been associated with some fatal adverse reactions when
administered to neonates. It is now recommended that parenteral
products preserved with benzyl alcohol, or other antimicrobial
preservatives, should not be used in newborn infants if at all
possible.
Kontakt-Allergie
Benzyl alcohol is mainly a preservative, mostly used in
topical antimycotic or corticosteroid ointments. It is
also a component catalyst for epoxy resins and is contained
in the color developer C-22. As a fragrance
allergen, it has to be mentioned by name in cosmetics
within the EU.
Carcinogenicity
In an NTP study, F344 rats were
dosed by oral gavage with 0, 200, and 400 mg/kg, 5 days/
week for 2 years. Benzyl alcohol had no effect on the survival
of male rats; female rats had reduced survival, and many of
the early deaths were considered related to the gavage
procedure. There were no treatment-related effects on nonneoplastic
or neoplastic lesions in either sex treated with
benzyl alcohol. It was concluded that under the conditions of
the study, there was no evidence of carcinogenic activity
. In the same NTP study, B6C3F1 mice were dosed by
oral gavage with 0, 100, and 200 mg/kg, 5 days/week for
2 years. No effects on survival or body weight gain were
observed. There were no treatment-related effects on nonneoplastic
or neoplastic lesions in either sex. It was concluded
that under the conditions of the study, there was no
evidence of carcinogenic activity.
Environmental Fate
Biological. Heukelekian and Rand (1955) reported a 5-d BOD value of 1.55 g/g which is 61.5%
of the ThOD value of 2.52 g/g.
Chemical/Physical. Slowly oxidizes in air to benzaldehyde (Huntress and Mulliken, 1941).
Benzyl alcohol will not hydrolyze because it has no hydrolyzable functional group (Kollig, 1993).
Stoffwechsel
Esters of benzyl alcohol are rapidly hydrolysed in vivo to benzyl alcohol, which is then oxidized . The animal organism readily oxidizes benzyl alcohol to benzoic acid, which after conjugation with glycine is rapidly eliminated as hippuric acid in the urine.
Benzyl alcohol is oxidised by alcohol dehydrogenase (AlcDH), a cytoplasmic enzyme present mainly in the liver, but also in the intestine and kidney. This reaction is saturable. The benzaldehyde formed is oxidised by aldehyde dehydrogenases (AldDH), cytoplasmic and mitochondrial enzymes mainly present in the liver, but also in the intestine and numerous organs.
Lager
Benzyl alcohol oxidizes slowly in air to benzaldehyde and benzoic
acid; it does not react with water. Aqueous solutions may be
sterilized by filtration or autoclaving; some solutions may generate
benzaldehyde during autoclaving.
Benzyl alcohol may be stored in metal or glass containers. Plastic
containers should not be used; exceptions to this include
polypropylene containers or vessels coated with inert fluorinated
polymers such as Teflon.
Benzyl alcohol should be stored in an airtight container,
protected from light, in a cool, dry place.
läuterung methode
It is usually purified by careful fractional distillation under reduced pressure in the absence of air. Benzaldehyde, if present, can be detected by UV absorption at 283nm. It has also been purified by shaking with aqueous KOH and extracting with peroxide-free diethyl ether. After washing with water, the extract is treated with saturated NaHS solution, filtered, washed, dried with CaO and distilled under reduced pressure [Mathews J Am Chem Soc 48 562 1926]. Peroxy compounds can be removed by shaking with a solution of Fe2+ followed by washing the alcohol layer with distilled water and fractionally distilling it. [Beilstein 6 IV 2222.]
Inkompatibilitäten
Benzyl alcohol is incompatible with oxidizing agents and strong
acids. It can also accelerate the autoxidation of fats.
Although antimicrobial activity is reduced in the presence of
nonionic surfactants, such as polysorbate 80, the reduction is less
than is the case with hydroxybenzoate esters or quaternary
ammonium compounds.
Benzyl alcohol is incompatible with methylcellulose and is only
slowly sorbed by closures composed of natural rubber, neoprene,
and butyl rubber closures, the resistance of which can be enhanced
by coating with fluorinated polymers. However, a 2% v/v
aqueous solution in a polyethylene container, stored at 208℃, may
lose up to 15% of its benzyl alcohol content in 13 weeks. Losses
to polyvinyl chloride and polypropylene containers under similar
conditions are usually negligible. Benzyl alcohol can damage
polystyrene syringes by extracting some soluble components
Regulatory Status
Included in the FDA Inactive Ingredients Database (dental
injections, oral capsules, solutions and tablets, topical, and vaginal
preparations). Included in parenteral and nonparenteral medicines
licensed in the UK. Included in the Canadian List of Acceptable
Non-medicinal Ingredients.
Benzylalkohol Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
Benzylbutyrat
Methylbenzolsulfonat
4-BENZYLOXY-2(1 H)-PYRIDONE
DIBENZYL DIISOPROPYLPHOSPHORAMIDITE
Benzenemethanol, ar-methyl-, acetate
CYCLOPROTHRIN
Phenylmethylchloracetat
5-(BENZYLOXY)-1H-PYRROLO[3,2-B]PYRIDINE-2-CARBALDEHYDE
Azobenzol
4-BENZYLOXY-5-BROMO-2-CHLOROPYRIMIDINE
5-(BENZYLOXY)PYRIDIN-3-AMINE
4-(Benzyloxy)pyridine N-oxide
3-Amino-5-hydroxypyridine
4-BENZYLOXY-2-CHLOROPYRIMIDINE
6-benzylaminopurine
2-(Diphenylmethoxy)-N,N-dimethyl-ethanamin
GUSPERIMUS
BENZHYDRYL B-CHLOROETHYL ETHER
3-(BENZYLOXY)-5-BROMOPYRIDINE
Benzylisobutyrat
3-Hydroxy-alpha-((methylamino)-methyl)benzolethanol-hydro-chlorid, (R)
3-Amino-5-fluoropyridine
N5-[Imino(phosphonoamino)methyl]L-ornithin
Benzylisovalerat
Benzylcinnamat
2 , 4-BIS(BENZYLOXY)-5-BROMOPYRIMIDINE
Benzylbutylether
Benzylpropionat
Ameisensäure-phenylmethylester
5,12-DIHYDRO-5,7,12,14-TETRAZAPENTACENE
Phenyl-methyl -hydroxybenzenebutanoate
6-BENZYLOXYPURINE
scavenger of fabric maculae
Dibenzylether
Benzylacetat
Benzylbenzoat
6-O-Benzylguanine
Benzyl-2-methylcrotonat
4,6-Diamino-2-pyrimidinol
PHOSPHO-L-ARGININE SODIUM
