Iod Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
SCHWARZBLAUE ODER DUNKELVIOLETTE KRISTALLE MIT STECHENDEM GERUCH.
PHYSIKALISCHE GEFAHREN
Iod sublimiert leicht.
CHEMISCHE GEFAHREN
Beim Erhitzen bilden sich giftige Rauche. Starkes Oxidationsmittel. Reagiert mit brennbaren und reduzierenden Stoffen. Reagiert sehr heftig mit Metallpulvern, Antimon, Ammoniak, Acetaldehyd, Acetylen unter Feuer- und Explosionsgefahr.
ARBEITSPLATZGRENZWERTE
TLV: 0.1 ppm (als STEL, ceiling); (ACGIH 2005).
MAK: IIb (nicht festgelegt, aber Informationen vorhanden) (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 schnell eine gesundheitssch?dliche Kontamination der Luft eintreten.
WIRKUNGEN BEI KURZZEITEXPOSITION
WIRKUNGEN BEI KURZZEITEXPOSITION: Tr?nenreizend. Die Substanz reizt stark die Augen, die Atemwege und die Haut. Inhalation des Dampfes kann zu Asthma(Reaktives Atemwegsfunktionsst?rungssyndrom RADS) und zu Lungen?dem führen (s.Anm.). Die Auswirkungen treten u.U. verz?gert ein. ?rztliche Beobachtung notwendig.
WIRKUNGEN NACH WIEDERHOLTER ODER LANGZEITEXPOSITION
Wiederholter oder andauernder Hautkontakt kann in seltenen F?llen zu Hautsensibilisierung und zu asthma?hnlichem Syndrom (RADS) führen. M?glich sind Auswirkungen auf die Schilddrüse.
LECKAGE
Verschüttetes Material in abdichtbaren Beh?ltern sammeln; falls erforderlich durch Anfeuchten Staubentwicklung verhindern. Reste sorgf?ltig sammeln. An sicheren Ort bringen. NICHT mit S?gemehl oder anderen brennbaren Absorptionsmitteln binden. NICHT in die Umwelt gelangen lassen. Pers?nliche Schutzausrüstung: Atemschutzfilter für anorganische Gase und D?mpfe sowie Halogene.
R-S?tze Betriebsanweisung:
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
R50:Sehr giftig für Wasserorganismen.
R20/21:Gesundheitssch?dlich beim Einatmen und bei Berührung mit der Haut.
S-S?tze Betriebsanweisung:
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S61:Freisetzung in die Umwelt vermeiden. Besondere Anweisungen einholen/Sicherheitsdatenblatt zu Rate ziehen.
S25:Berührung mit den Augen vermeiden.
S23:Gas/Rauch/Dampf/Aerosol nicht einatmen(geeignete Bezeichnung(en) vom Hersteller anzugeben).
Aussehen Eigenschaften
I2, elementar, Kristallplättchen tief violett
Gefahren für Mensch und Umwelt
Gefährliche Reaktionen: Mit Alkalimetallen, Ammoniak, Nichtmetallen, Halogen-halogenverb., Acetyliden, Halbmetallen, Aluminium, Acetylen, Acetaldehyd, Carbiden, Fluor, Magnesium, Quecksilber, Lithiumsilicid, Silberazid, Terpentin, Cäsiumoxid, Calciumhydrid
Hautkontakt führt zu Pigmentverlust. Nach Verschlucken treten Metallgeschmack, blutige Durchfälle, Fieber und Kollaps auf. Das Einatmen von Joddämpfen verätzt die Atemwege. Chronische Aufnahme verursacht Hautveränderungen ("Jodakne") und allergische Reaktionen mit Schnupfen, Bindehautentzündung, Bronchitis und Asthma.; LD50 (oral, Ratte): 14000 mg/kg
Schwach wassergefährdend (WGK 1).
Schutzma?nahmen und Verhaltensregeln
Dicht verschlossen, an gut belüftetem Ort.
Bei Auftreten von Dämpfen/Aerosolen
Schutzbrille mit Seitenschutz und oberer Augenraumabdeckung
Neopren-Schutzhandschuhe als kurzzeitiger Spritz- und Staubschutz
Verhalten im Gefahrfall
Reinigungsverfahren: trocken aufnehmen, der Sondermüllentsorgung zuführen, Nachreinigen
Erste Hilfe
Nach Hautkontakt: Mit viel Wasser abwaschen
Nach Augenkontakt: 15 Minuten bei gespreizten Lidern unter fließendem Wasser mit Augendusche ausspülen. Augenarzt konsultieren!
Nach Einatmen: Frischluft.
Nach Verschlucken: Viel milch (evtl. Wasser od.Haferschleim) trinken. Natriumsulfat verabreichen. Arzt befragen!
Ersthelfer: siehe gesonderten Anschlag
Sachgerechte Entsorgung
Falls Recycling nicht möglich, als Sonderabfall entsorgen, zuständige Stellen: Hubland-Herr Riepl:8884711, Klinikum-Herr Uhl:2015557.
Beschreibung
Iodine was discovered in 1811 by Bernard Courtois, and is
classed among the rarer elements. Iodine is found naturally in
seaweed, and is considered and generally recognized as safe
substance by the US Food and Drug Administration (FDA).
Iodine is a required element by many species, including
humans. It has been recognized as preventative against goiter
since 1819, and is used in iodized salt for this purpose. Iodine
is also used as a dough oxidizer in commercial bread making.
Iodine is generally extracted from natural and oil field brines by
means of oxidation of iodide with chlorine, then removal from
solution with an airstream. Iodine is reabsorbed in solution
and reduces to hidrotic acid with sulfur dioxide. The solution is
then chlorinated to precipitate free iodine, and is further
purified by treatment with concentrated sulfuric acid. Iodine is
the heaviest essential element for most life, with tungsten being
used by some bacteria.
Physikalische Eigenschaften
Bluish-black orthorhombic crystals; refractive index 3.34; density of solid4.933 g/cm3at 20°C; density of the element in liquid form at 120°C 3.96 g/cm3;melts at 113.6°C to a black mobile liquid; the solid can be sublimed to vaporbelow its melting point; vapor pressure of solid at 25°C 0.3075 torr; vaporpressure at 113.6°C 90.5 torr; the liquid boils at 184.3°C giving violet vapors;vapor density 6.75 g/L; critical temperature 545.8°C; critical pressure 48.9atm; critical volume 155 cm3/mol; dielectric constant of solid 10.3 at 23°C and liquid 11.08 at 118°C; resistivity 5.85 x 106ohm-cm at 25°C, and 1.10 x 105ohm-cm at 140°C; slightly soluble in water, 0.33 g/L at 25°C; soluble inethanol, carbon disulfide, benzene and chloroform, forming brown solutions;sulfur, selenium, metal iodides and many organic compounds dissolve in liq-uid iodine.
Verwenden
Iodine is used in the manufacture of manyiodine compounds; in photographic materi als; as an antiseptic, disinfectant, and germi cide; and as a reagent in analytical chemistry.It occurs in traces in seawater and in igneousrocks.
Vorbereitung Methode
In the United States, the principal method
used to recover iodine from oil brines involves the oxidation
of iodide by chlorine, followed by removal of the volatile
iodine from solution with an airstream. The iodine is reabsorbed
in solution and reduced to hidrotic acid with sulfur
dioxide. The solution is then chlorinated to precipitate free
iodine, which is further purified by treatment with concentrated
sulfuric acid. The same process is used to recover
iodine from natural brines. In the recovery of iodine from
Chilean nitrate deposits, solutions containing the iodates are
reduced with sodium bisulfite to precipitate the iodine, which
is then purified by sublimation.
Definition
ChEBI: Molecule comprising two covalently bonded iodine atoms with overall zero charge..
Biologische Funktion
Inhibition of the release of thyroid hormone by iodide is the basis for its use in hyperthyroidism. Iodide
decreases the vascularity of the enlarged thyroid gland and also lowers the elevated BMR. It also has been
suggested that excess iodide might change the conformation of thyroglobulin, making the protein less
susceptible to thyroidal proteolysis.
Allgemeine Beschreibung
Violet-black crystals with a metallic luster and a sharp odor. Mp: 133.5°C, bp: 185°C. Emits toxic vapor at room conditions; vapor becomes visibly purple when its concentration builds up in a confined space. Nearly insoluble in water but very soluble in aqueous solutions of iodides.
Reaktivit?t anzeigen
Iodine is an oxidizing agent. Reacts vigorously with reducing materials. Incompatible with powdered metals in the presence of water (ignites), with gaseous or aqueous ammonia (forms explosive products), with acetylene (reacts explosively), with acetaldehyde (violent reaction), with metal azides (forms yellow explosive iodoazides), with metal hydrides (ignites), with metal carbides (ignites easily), with potassium and sodium (forms shock-senstive explosive compounds) and with alkali-earth metals (ignites). Incompatible with ethanol, formamide, chlorine, bromine, bromine trifluoride, chlorine trifluoride.
Hazard
Iodine vapors are an irritant to eyes, nose and mucous membranes.Inhalation can cause headache, irritation, and congestion of lungs. Oralintake can produce burning of the mouth, vomiting, diarrhea, and abdominalcramps. Skin contact can cause rashes.
Health Hazard
The acute toxicity of iodine by inhalation is high. Exposure may cause severe
breathing difficulties, which may be delayed in onset; headache, tightness of the
chest, and congestion of the lungs may also result. In an experimental investigation,
four human subjects tolerated 0.57 ppm iodine vapor for 5 min without eye
irritation, but all experienced eye irritation in 2 min at 1.63 ppm. Iodine in
crystalline form or in concentrated solutions is a severe skin irritant; it is not easily
removed from the skin, and the lesions resemble thermal burns. Iodine is more toxic
by the oral route in humans than in experimental animals; ingestion of 2 to 3 g of the
solid may be fatal in humans.
Iodine has not been found to be carcinogenic or to show reproductive or
developmental toxicity in humans. Chronic absorption of iodine may cause
insomnia, inflammation of the eyes and nose, bronchitis, tremor, rapid heartbeat,
diarrhea, and weight loss.
Flammability and Explosibility
Iodine is noncombustible and in itself represents a negligible fire hazard when
exposed to heat or flame. However, when heated, it will increase the burning rate of
combustible materials.
Environmental Fate
Iodine is released into the environment during nuclear explosions,
as well as around any fuel rods, primarily spent. Due to
iodine’s uses, it is frequently released into the environment, but
adsorbs many minerals as well as organic masses, which inhibit
transport.
Lager
safety goggles and rubber gloves should be worn when handling
iodine, and operations involving large quantities should be conducted in a fume hood to
prevent exposure to iodine vapor or dusts by inhalation.
l?uterung methode
It is usually purified by vacuum sublimation. Preliminary purifications include grinding with 25% by weight of KI, blending with 10% BaO and subliming, subliming with CaO, grinding to a powder and treating with successive portions of H2O to remove dissolved salts, then drying, and recrystallising from *benzene. Barrer and Wasilewski [Trans Faraday Soc 57 1140 1961] dissolved I2 in concentrated KI and distilled it, then steam distilled it three times and washed it with distilled H2O. Organic material is removed by sublimation in a current of O2 over platinum at about 700o, the iodine being finally sublimed under vacuum. HARMFUL VAPOURS.
Inkompatibilit?ten
Iodine is stable under normal temperatures and pressures. Iodine may react violently
with acetylene, ammonia, acetaldehyde, formaldehyde, acrylonitrile, powdered
antimony, tetraamine copper(II) sulfate, and liquid chlorine. Iodine can form
sensitive, explosive mixtures with potassium, sodium, and oxygen difluoride;
ammonium hydroxide reacts with iodine to produce nitrogen triiodide, which
detonates on drying.
Waste disposal
Excess iodine and waste material containing this substance should be placed in an appropriate
container, clearly labeled, and handled according to your institution's waste disposal
guidelines. For more information on disposal procedures, see Chapter 7 of this volume.
Vorsichtsma?nahmen
Students, users, and occupational workers should specially note iodine as: Poison, Danger,
and Corrosive. Exposures cause severe irritation or burns to every area of contact. It may
be fatal if ingested/swallowed/inhaled. The vapors cause severe irritation to the skin,
eyes, and respiratory tract. Iodine is a strong oxidizer and contact with other material may
cause fi re.
Occupational workers should wear impervious protective clothing, boots, gloves, a lab-
oratory coat, apron or coveralls, as appropriate, to prevent skin contact of iodine. Also,
workers should use chemical safety goggles and/or a full-face shield where splashing is
possible. Maintain an eye-wash fountain and quick-drench facilities in the work area.
Iod Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
