Thiomersal Chemische Eigenschaften,Einsatz,Produktion Methoden
R-Sätze Betriebsanweisung:
R26/27/28:Sehr giftig beim Einatmen, Verschlucken und Berührung mit der Haut.
R33:Gefahr kumulativer Wirkungen.
R50/53:Sehr giftig für Wasserorganismen, kann in Gewässern längerfristig schädliche Wirkungen haben.
S-Sätze Betriebsanweisung:
S13:Von Nahrungsmitteln, Getränken und Futtermitteln fernhalten.
S28:Bei Berührung mit der Haut sofort abwaschen mit viel . . . (vom Hersteller anzugeben).
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn möglich, dieses Etikett vorzeigen).
S60:Dieses Produkt und sein Behälter sind als gefährlicher Abfall zu entsorgen.
S61:Freisetzung in die Umwelt vermeiden. Besondere Anweisungen einholen/Sicherheitsdatenblatt zu Rate ziehen.
Chemische Eigenschaften
Thimerosal is a light cream-colored crystalline powder with a slight,
characteristic odor.
Verwenden
Thimerosal is used as ophthalmie preservative; topieal anti-infective; topical veterinary antibacterial and antifungal agent; bacteriostat; fungistat;
preservative in vaccines, antitoxins, skin-testing allergens, antiseptics, contact-Iens solutions, and cosmetic products like eye makeup.
Definition
ChEBI: An alkylmercury compound (approximately 49% mercury by weight) used as an antiseptic and antifungal agent.
Vorbereitung Methode
Thimerosal is prepared by the interaction of ethylmercuric chloride,
or hydroxide, with thiosalicylic acid and sodium hydroxide, in
ethanol (95%).
Allgemeine Beschreibung
Light cream-colored crystalline powder with a slight odor: pH (1% aqueous solution) 6.7. Slight odor.
Air & Water Reaktionen
Water soluble.
Reaktivität anzeigen
Thimerosal is incompatible with strong oxidizing agents and strong bases. The oxidation of Thimerosal is greatly accelerated by traces of copper ions. Incompatible with acids, iodine, heavy metal salts and many alkaloids. Can be absorbed by rubber caps. . Stable in air, but not sunlight. May discolor on exposure to light. Dilute aqueous solutions are fairly stable to heat but sensitive to light. Solutions are less stable to heat when acidic than when alkaline. Solutions are most stable to light at pH 5 to 7. Solutions are unstable to heat but not to light in the presence of copper, iron or zinc ions but not in the presence of calcium or magnesium ions.
Hazard
Toxic by ingestion, inhalation.
Brandgefahr
Flash point data for Thimerosal are not available; however, Thimerosal is probably combustible.
Pharmazeutische Anwendungen
Thimerosal has been used as an antimicrobial preservative in
biological and pharmaceutical preparations since the 1930s.
It is used as an alternative to benzalkonium chloride and other
phenylmercuric preservatives, and has both bacteriostatic and
fungistatic activity. Increasing concerns over its safety have,
however, led to questions regarding its continued use in formulations.
Thimerosal is also used in cosmetics and to
preserve soft contact lens solutions.
Therapeutically, thimerosal is occasionally used as a bacteriostatic
and fungistatic mercurial antiseptic, which is usually applied
topically at a concentration of 0.1% w/w. However, its use is
declining owing to its toxicity and effects on the environment.
Kontakt-Allergie
Thiomersal is an organic mercury salt prepared by react-
ing ethylmercuric chloride (or ethylmercuric hydroxide)
with thiosalicylic acid. It is still used as a disinfectant
and a preservative agent, but less commonly than previ-
ously, especially in contact lens fluids, eyedrops, and
vaccines. The ethylmercuric moiety is the major aller-
genic determinant, sometimes associated with mercury
sensitivity. Thiomersal is an indicator of photosensitiv-
ity to piroxicam, through its thiosalicylic moiety.
Sicherheitsprofil
Poison by ingestion,
subcutaneous, and intravenous routes.
Experimental teratogenic and reproductive
effects. An eye irritant. Questionable carcinogen with experimental neoplastigenic
data. Mutation data reported. An ophthalmic
preservative, a topical anti-infective, topical
veterinary antibacterial and antifungal agent.
An FDA over-the-counter drug. When
heated to decomposition it emits very toxic
fumes of Hg, Na2O, and SOx. See also
MERCURY COMPOUNDS.
Environmental Fate
Thimerosal is a cream-colored crystalline powder; it is water
soluble and thus the compound can leach into groundwater.
Aquatic toxicity has been demonstrated at relatively high
concentrations.
Lager
Thimerosal is stable at normal temperatures and pressures;
exposure to light may cause discoloration.
Aqueous solutions may be sterilized by autoclaving but are
sensitive to light. The rate of oxidation in solutions is increased by
the presence of trace amounts of copper and other metals. Edetic
acid or edetates may be used to stabilize solutions but have been
reported to reduce the antimicrobial efficacy of thimerosal
solutions.
The solid material should be stored in a well-closed container,
protected from light, in a cool, dry place.
läuterung methode
Recrystallise this antibacterial from EtOH/Et2O. HIGHLY TOXIC. [Trikojus Nature 158 472 1940, Beilstein 10 III 213.]
Inkompatibilitäten
Incompatible with aluminum and other metals, strong oxidizing
agents, strong acids and bases, sodium chloride solutions,
lecithin, phenylmercuric compounds, quaternary ammonium compounds,
thioglycolate, and proteins. The presence of sodium
metabisulfite, edetic acid, and edetates in solutions can reduce the
preservative efficacy of thimerosal.
In solution, thimerosal may be adsorbed by plastic packaging
materials, particularly polyethylene. It is strongly adsorbed by
treated or untreated rubber caps that are in contact with
solutions.
When it was used with cyclodextrin, the effectiveness of
thimerosal was reduced; however, this was related to the lipid
nature of the other ingredients in the preparation.
Regulatory Status
Included in the FDA Inactive Ingredients Database (IM, IV, and SC
injections; ophthalmic, otic, and topical preparations). Included in
nonparenteral and parenteral medicines licensed in the UK. In the
UK, the use of thimerosal in cosmetics is limited to 0.003% w/w
(calculated as mercury) as a preservative in shampoos and haircreams,
which contain nonionic emulsifiers that would render other
preservatives ineffective. The total permitted concentration (calculated
as mercury) when mixed with other mercury compounds is
0.007% w/w. Included in the Canadian List of Acceptable Nonmedicinal
Ingredients.
Thiomersal Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
