Distickstoffoxid Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
FARBLOSES KOMPRIMIERTES FLüSSIGGAS MIT CHARAKTERISTISCHEM GERUCH.
PHYSIKALISCHE GEFAHREN
Das Gas ist schwerer als Luft. Es kann sich in tiefer gelegenen Bereichen sammeln und den Luftsauerstoff verdrängen.
CHEMISCHE GEFAHREN
Reagiert sehr heftig mit Schwefelsäureanhydrid, amorphem Bor, Phosphorwasserstoff, Ethern, Aluminium, Hydrazin, Phenyllithium und Wolframcarbid Feuer- und Explosionsgefahr. Oberhalb 300 °C ist das Gas ein starkes Oxidationsmittel und kann explosionsfähige Gemische mit Ammoniak, Kohlenmonoxid, Schwefelwasserstoff, öl, Fett und Kraftstoffen bilden.
ARBEITSPLATZGRENZWERTE
TLV: 50 ppm (als TWA); Krebskategorie A4 (nicht klassifizierbar als krebserzeugend für den Menschen); (ACGIH 2005).
MAK: 100 ppm; 180 mg/m? Spitzenbegrenzung: überschreitungsfaktor II(2); Schwangerschaft: Gruppe C; (DFG 2006)
AUFNAHMEWEGE
Aufnahme in den Körper durch Inhalation.
INHALATIONSGEFAHREN
Eine gesundheitsschädliche Konzentration des Gases in der Luft wird beim Entweichen aus dem Behälter sehr schnell erreicht.
WIRKUNGEN BEI KURZZEITEXPOSITION
WIRKUNGEN BEI KURZZEITEXPOSITION: Die Flüssigkeit kann Erfrierungen hervorrufen. Möglich sind Auswirkungen auf das Zentralnervensystem mit nachfolgender Bewusstseinstrübung.
WIRKUNGEN NACH WIEDERHOLTER ODER LANGZEITEXPOSITION
Möglich sind Auswirkungen auf das Knochenmarkund das periphere Nervensystem. Kann fruchtbarkeitsschädigend oder entwicklungsschädigend wirken.
LECKAGE
Gefahrenbereich verlassen! Fachmann zu Rate ziehen! Belüftung. In flüssigem Zustand: NICHT mit Sägemehl oder anderen brennbaren Absorptionsmitteln binden. Wasserstrahl NIEMALS auf die Flüssigkeit richten. Persönliche Schutzausrüstung: Umgebungsluftunabhängiges Atemschutzgerät.
R-Sätze Betriebsanweisung:
R8:Feuergefahr bei Berührung mit brennbaren Stoffen.
S-Sätze Betriebsanweisung:
S38:Bei unzureichender Belüftung Atemschutzgerät anlegen.
Beschreibung
dinitrogen monoxide’s (N2O)
common name is nitrous oxide.Nitrous oxide is a colorless, nonfl ammable,
nontoxic gas with a slightly sweet odor and taste. Nitrous oxide is produced by
the thermal decomposition of ammonium nitrate at approximately 240°C: NH4NO3(g) →
N2O(g) + 2H2O(g).Nitrous oxide is an important greenhouse gas.
Its atmospheric residence time is 120 years. A molecule of N2O has 310 times the potential
for absorbing heat compared to a molecule of CO2. Nitrous oxide is stable and unreactive on
the earth’s surface, but it can be transported to the stratosphere where it absorbs energy and is
converted into reactive forms of nitrogen such as nitric oxide and the nitrate radical contributing
to ozone destruction.
Chemische Eigenschaften
Nitrous oxide is a colorless gas. Slightly sweet
odor. Shipped as a liquefied compressed gas.
Physikalische Eigenschaften
Colorless gas with faint sweet odor and taste; heavier than air, density in air 1.53 (air=1); gas density 1.977 g/L at 0°C; noncombustible gas; supports combustion; liquefies to a colorless liquid at -88.5°C; liquid density 1.226 g/mL at -89°C; freezes to a cubic crystalline solid at -90.8°C; dipole moment 0.166 ; critical temperature 36.5°C; critical pressure 71.7 atm; solubility in water: 130 mL gas dissolves in 100mL water at 0°C and 56.7 mL in 100 mL water at 25°C; soluble in alcohol, ether and sulfuric acid.
History
nitrous oxide was prepared in 1772 by Joseph Priestley (1733 1804) . Priestley called nitric oxide nitrous air, nitrogen dioxide nitrous acid vapor, and nitrous oxide phlogisticated nitrous air, but also referred to the dioxide. Priestley prepared nitric oxide by reacting nitric acid with a metal such as copper: 3Cu(s) + 8HNO3(aq) 2NO(g) + 3Cu(NO3)2(aq) + 4H2O(l).He prepared nitrous oxide by reducing nitric oxide using iron: 2NO(g) + H2O(l) + Fe(s) N2O(g) + Fe(OH)2(aq).For example, the year of discovery for nitrous oxide ranges between 1772 and 1793. Humphrey Davy (1778 1829) examined the physiological effects of nitrous oxide and in 1799 wrote Researches Chemical and Philosophical, Chiefly Concerning Nitrous Oxide.
Verwenden
Nitrous oxide was discovered by Priestley. It is found in the atmosphere in trace concentrations. The gas is used as an anesthetic, especially in dentistry and minor surgery. It produces mild hysteria and laughter preceding the anesthetic effect, for which reason it also is called “laughing gas.” It is used as an aerosol propellant, an aerating agent for whipped cream, and an oxidizing agent at high temperatures. Nitrous oxide also is used in the preparation of nitrites and as a flame gas in flame atomic absorption spectrometry of metals.
Definition
ChEBI: A nitrogen oxide consisting of linear unsymmetrical molecules with formula N2O. While it is the most used gaseous anaesthetic in the world, its major commercial use, due to its solubility under pressure in vegetable fats combined with
ts non-toxicity in low concentrations, is as an aerosol spray propellant and aerating agent for canisters of 'whipped' cream.
Vorbereitung Methode
Nitrous oxide is prepared by heating ammonium nitrate to about
170°C. This reaction also forms water.
synthetische
Prepared by thermal decomposition of ammonium nitrate
NH
4NO
3 → N
2O↑ + 2H
2O
Allgemeine Beschreibung
NITROUS OXIDE is a colorless, sweet-tasting gas. NITROUS OXIDE is also known as "laughing gas". Continued breathing of the vapors may impair the decision making process. NITROUS OXIDE is noncombustible but NITROUS OXIDE will accelerate the burning of combustible material in a fire. NITROUS OXIDE is soluble in water. Its vapors are heavier than air. Exposure of the container to prolonged heat or fire can cause NITROUS OXIDE to rupture violently and rocket. NITROUS OXIDE is used as an anesthetic, in pressure packaging, and to manufacture other chemicals.
Reaktivität anzeigen
NITROUS OXIDE is an oxidizing agent. Nonflammable but supports combustion. Can explode at high temperature (after vaporization). Vapors can undergo a violent reaction with aluminum, boron, hydrazine, lithium hydride, phenyllithium, phosphine, sodium, tungsten carbide [Bretherick, 5th ed., 1995, p. 1686]. Contact of the cold liquefied gas with water may result in vigorous or violent boiling. If the water is hot, a liquid "superheat" explosion may occur. Pressures may build to dangerous levels if liquefied gas contacts water in a closed container [Handling Chemicals Safely 1980].
Hazard
Supports combustion, can form explosive
mixture with air. Narcotic in high concentration.
Central nervous system impairment, hematologic
effects, and embryo/fetal damage. Questionable
carcinogen.
Health Hazard
Toxicity and irritant effects of nitrous oxidein humans are very low. It is an anesthetic.Inhalation of this gas at high concentrationscan produce depression of the central nervous system, decrease in body temperature,and fall in blood pressure. The LC50 valueof a 4-hour exposure in mice is in the rangeof 600 ppm.
Brandgefahr
Behavior in Fire: Will support combustion, and may increase intensity of fire. Containers may explode when heated.
Materials Uses
Nitrous oxide is noncorrosive and may therefore
be used with any of the common, commercially
available metals. Because of its oxidizing action, however, all equipment being prepared to
handle nitrous oxide, particularly at high pressures, must be free of oil, grease, and other
readily combustible materials. Nitrous oxide
may cause swelling ofsome elastomers.
Clinical Use
The low potency of nitrous oxide (MAC＝ 104%) precludes it from being used alone for surgical anesthesia.To use it as the sole anesthetic agent the patient wouldhave to breathe in pure N
2Oto the exclusion of oxygen. Thissituation would obviously cause hypoxia and potentially leadto death. Nitrous oxide can inactivate methionine synthase, aB12-dependent enzyme necessary for the synthesis of DNAand therefore should be used with caution in pregnant andB12-deficient patients. Nitrous oxide is also soluble in closedgas containing body spaces and can cause these spaces toenlarge when administered possibly leading to adverse occurrences(occluded middle ear, bowel distension, pneumothorax).Nitrous oxide is a popular anesthetic in dentistrywere it is commonly referred to as “laughing gas.” It is usedin combination with more potent anesthetics for surgicalanesthesia and remains a drug of recreational abuse.Nitrous oxide undergoes little or no metabolism.
Sicherheitsprofil
Moderately toxic by
inhalation. Human systemic effects by
inhalation: general anesthetic, decreased
pulse rate without blood pressure fall, and
body temperature decrease. An experimental
teratogen. Experimental reproductive
effects. Mutation data reported. An
asphyxiant. Does not burn but is flammable
by chemical reaction and supports
combustion. Moderate explosion hazard; it
can form an explosive mixture with air.
Violent reaction with Al, B, hydrazine, LiH,
LiC6H5, PH3, Na, tungsten carbide. Also
self-explodes at high temperatures.
Sicherheit(Safety)
Nitrous oxide is most commonly used therapeutically as an
anesthetic and analgesic. Reports of adverse reactions to nitrous
oxide therefore generally concern its therapeutic use, where
relatively large quantities of the gas may be inhaled, rather than
its use as an excipient.
The main complications associated with nitrous oxide inhalation
occur as a result of hypoxia. Prolonged administration may also be
harmful. Nitrous oxide is rapidly absorbed on inhalation.
mögliche Exposition
Used as an anesthetic in dentistry and
surgery; used as a gas in food aerosols, such as whipped
cream; used in manufacture of nitrites; used in rocket fuels;
in firefighting; diesel emissions. Large amounts of nitrous
oxide will decrease the amount of available oxygen.
Nitrous Oxide 2231
Oxygen should be routinely tested to ensure that it is at
least 19% by volume.
Carcinogenicity
The possible carcinogenicity of nitrous
oxide has been studied in dentists and chairside
assistants with occupational exposures. No
effect was observed in male dentists, but a 2.4-
fold increase in cancer of the cervix in heavily
exposed female assistants was reported.7 Other
epidemiological reports of workers exposed to
waste anesthetic gases have been negative.1
Carcinogenic bioassays in animals have yielded
negative results. Nitrous oxide was not genotoxic
in a variety of assays.
Lager
Nitrous oxide is essentially nonreactive and stable except at high
temperatures; at a temperature greater than 500°C nitrous oxide
decomposes to nitrogen and oxygen. Explosive mixtures may be
formed with other gases such as ammonia, hydrogen, and other
fuels. Nitrous oxide should be stored in a tightly sealed metal
cylinder in a cool, dry place.
Versand/Shipping
UN1070 Nitrous oxide, compressed, Hazard
Class: 2.2; Labels: 2.2-Nonflammable compressed gas;
5.1-Oxidizer; UN2201 Nitrous oxide, refrigerated liquid,
Hazard Class: 2.2; Labels: 2.2-Nonflammable compressed
gas; 5.1-Oxidizer. 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.
läuterung methode
Wash the gas with concentrated alkaline pyrogallol solution, to remove O2, CO2, and NO2, then dry it by passing it through columns of P2O5 or Drierite, and collecting in a dry trap cooled in liquid N2. It is further purified by freeze-pump-thaw and distillation cycles under vacuum [Ryan & Freeman J Phys Chem 81 1455 1977, Schenk in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I pp 484-485 1963].
Inkompatibilitäten
Nitrous oxide is a weak oxidizer.
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. Violent reactions with organic peroxides,
hydrazine, hydrogen, hydrogen sulfide; lithium, boron, lithium
hydride, sodium, aluminum, phosphine. This chemical
is a strong oxidizer @ .300C and self-explodes at high
temperature. May form explosive mixtures with ammonia,
carbon monoxide; hydrogen sulfide; oil, grease and fuels.
Waste disposal
Disperse in atmosphere or
spray on dry soda ash/lime with great care; then flush to
sewer.
Regulatory Status
GRAS listed. Accepted for use as a food additive in Europe.
Included in nonparenteral medicines licensed in the UK and USA.
Included in the Canadian List of Acceptable Non-medicinal
Ingredients.
Distickstoffoxid Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
