Dimethylquecksilber Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
FARBLOSE FLüSSIGKEIT.
PHYSIKALISCHE GEFAHREN
Die D?mpfe sind schwerer als Luft und k?nnen sich am Boden ausbreiten. Fernzündung m?glich.
CHEMISCHE GEFAHREN
Zersetzung beim Verbrennen unter Bildung giftiger Gase mitQuecksilberoxiden. Reagiert mit Halogenenund Oxidationsmitteln unter Feuergefahr.
ARBEITSPLATZGRENZWERTE
TLV: (als Hg) 0.01 mg/m? (als TWA); 0.03 mg/m? (als STEL); Hautresorption; (ACGIH 2005).
MAK: Hautresorption; Sensibilisierung der Haut; Krebserzeugend Kategorie 3B; (DFG 2005).
AUFNAHMEWEGE
Aufnahme in den K?rper durch Inhalation der D?mpfe, über die Haut und durch Verschlucken.
INHALATIONSGEFAHREN
Beim Verdampfen bei 20°C kann sehr schnell eine gesundheitssch?dliche Kontamination der Luft eintreten.
WIRKUNGEN BEI KURZZEITEXPOSITION
WIRKUNGEN BEI KURZZEITEXPOSITION: Die Substanz reizt die Augen, die Haut und die Atemwege. M?glich sind Auswirkungen auf das Zentralnervensystem mit nachfolgenden Funktionsst?rungen. Exposition kann zum Tod führen. Die Auswirkungen treten u.U. verz?gert ein. ?rztliche Beobachtung notwendig.
WIRKUNGEN NACH WIEDERHOLTER ODER LANGZEITEXPOSITION
M?glich sind Auswirkungen auf das Zentralnervensystem. Führt zu Funktionsst?rungen. M?glicherweise krebserzeugend für den Menschen. Fruchtbarkeitssch?digend oder entwicklungssch?digend.
LECKAGE
Zündquellen entfernen. Ausgelaufene Flüssigkeit in abgedeckten Beh?ltern sammeln. Reste mit Sand oder inertem Absorptionsmittel aufnehmen und an einen sicheren Ort bringen. NICHT in die Kanalisation spülen. NICHT in die Umwelt gelangen lassen. Chemikalienschutzanzug mit umgebungsluftunabh?ngigem Atemschutzger?t.
R-S?tze 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 Gew?ssern l?ngerfristig sch?dliche Wirkungen haben.
S-S?tze Betriebsanweisung:
S13:Von Nahrungsmitteln, Getr?nken 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 m?glich, dieses Etikett vorzeigen).
S60:Dieses Produkt und sein Beh?lter sind als gef?hrlicher Abfall zu entsorgen.
S61:Freisetzung in die Umwelt vermeiden. Besondere Anweisungen einholen/Sicherheitsdatenblatt zu Rate ziehen.
Beschreibung
The first indication of the extreme toxicity of dimethylmercury
(DMM) was documented in 1863 when two laboratory assistants
died of DMM poisoning while synthesizing DMM in the
laboratory of Frankland and Duppa. There are numerous reports
of people dying from alkyl mercury compounds including
a chemist who was preparing several thousand grams ofDMMin
his laboratory in 1974. The extreme toxicity was revisited in
1997, when Karen Wetterhahn, an internationally renowned
researcher of the carcinogenic effects of heavy metals on DNA
repair proteins, died within a few months after a single exposure
of less than a milliliter of DMM on her latex-covered hand.
DMM is extremely toxic and lethal at a dose of approximately
400 mg of mercury (equivalent to a few drops) or about
5mgkg-1 of body weight or as little as 0.1 ml
Chemische Eigenschaften
colourless liquid
Verwenden
Dimethylmercury is used as a reagent ininorganic synthesis, and as a reference standardfor mercury nuclear magnetic resonance(Hg NMR). It is an environmental pollutantfound in bottom sediments and also inthe bodies of birds and marine mammalssuch as whales and fishes. It occurs in fishesand birds along with monomethylmercury. Inhumans, its presence is attributed to the consumptionof pilot whale meat, cod fish, andother sea food.
Health Hazard
All alkylmercury compounds are highly toxicby all routes of exposure. There are manyserious cases of human poisoning frommethylmercury (Lu 2003). Outbreaks ofmass poisoning from consumption of contaminatedfish occurred in Japan during the1950s, causing a severe neurological disease,so-called “Minamata disease,” whichresulted in hundreds of deaths. A similaroutbreak of food poisoning from contaminatedwheat caused several hundred deathsin Iraq in 1972. A tragic death from a singleacute transdermal exposure to dimethylmercury(estimated between 0.1 to 0.5 mL) thatpenetrated into the skin through disposablelatex gloves has occurred (Blayney et al.1997; The New York Times, June 11, 1997).The symptoms reported were episodes ofnausea and vomiting occurring three monthsafter the exposure followed by onset ofataxia, slurred speech (dysarthia), and loss ofvision and hearing 2 months after that. Thedeath occurred in about six months after theaccident.
Methylmercury can concentrate in certainfetal organs, such as the brain. Thetarget organs are the brain and the centralnervous system. It can cause death, miscarriage,and deformed fetuses. Unlike inorganicmercury compounds, it can penetrate throughthe membrane barrier of the erythrocyte,accumulating at about 10 times greater concentrationthan that in the plasma (WHO1976). Its rate of excretion on the bloodlevel is very slow. It gradually accumulatesin the blood. Such accumulation was found toreach 60% equilibrium at about 90 days, culminatedafter 270 days (Munro and Willes,1978). Skin absorption exhibits the symptomsof mercury poisoning. The toxic thresholdconcentration of mercury in the wholeblood is usually in the range 40 to 50 μg/L,while the normal range should be below10 μg/L.
Brandgefahr
It is a flammable liquid; flash point 38°C
(101°F). The flammability of this compound,
its ease of oxidation and the energy of decomposition is relatively lower than
the alkyls of lighter metals. It is mildly
endothermic. The heat of formation, △H°f
is ＋75.3 kJ/mol (Bretherick 1995). Unlike
most other metal alkyls formed by elements
of lower atomic numbers, dimethylmercury
does not pose any serious fire or explosion
hazard. Although it does not ignite in air,
the compound is easily inflammable. It dissolves
in lower alcohols without any violent
decomposition. Heating with oxidizing substances
can cause explosion. Violent explosion
is reported with diboron tetrachloride at
－63°C (－81°F) under vacuum (Wartik et al.
1971).
Sicherheitsprofil
Suspected carcinogen.
Highly toxic. Mutation data reported. Easily
flammable. When heated to decomposition
it emits toxic fumes of Hg.
m?gliche Exposition
Dimethyl mercury has been
used as seed disinfectants and for fungicides. It has
also been used in organic synthesis.
Environmental Fate
DMM is a colorless liquid that is volatile at room temperature
(vapor pressure 62.3 mmHg) and is slightly soluble in water
(water solubility 8860 mg l
-1). There are no reports on the
partition behavior of DMM but it is known to readily evaporate
and is thus rarely found in sediment or soil. No reports were
found on the environmental persistence of DMM. While DMM
vaporizes, no studies were found on long range transport. The
lipophilicity ofDMMresults in its accumulation inadipose tissue,
plasma proteins, and brain. DMM has not been found in fish.
Versand/Shipping
UN2025 Mercury compounds, solid, n.o.s.,
Hazard Class: 6.1; Labels: 6.1-Poisonous materials,
Technical Name Required.
Inkompatibilit?ten
Incompatible with oxidizers (chlorates,
nitrates, peroxides, permanganates, perchlorates, chlorine,
bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases,
strong acids, oxoacids, epoxides. May be sensitive to light.
Dimethylquecksilber Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
