7439-97-6 Usage
Description
Mercury, also known as quicksilver or hydrargyrum, is a silver-white metal with the chemical symbol Hg. It has been known since antiquity and was used by alchemists. Mercury has been used commercially and medically for centuries, but its use has been drastically reduced in recent years due to its neurological effects.
Uses
Used in Electrical and Electrolytic Applications:
Mercury is used in mercury batteries and cells for portable radios, microphones, cameras, hearing aids, watches, smoke alarms, and wiring and switching devices. It is also used in mercury vapor lamps, fluorescent tubes, and electrical discharge tubes. Mercury electrodes are widely used in electrolytic cells, and mercury cathodes are employed in the electrolysis of sodium chloride to produce caustic soda and chlorine.
Used in Thermometers, Manometers, Barometers, and Pressure-Sensing Devices:
Mercury is used in thermometers, manometers, barometers, and other pressure-sensing devices due to its unique properties.
Used as a Catalyst in Making Urethane Foams and Vinyl Chloride Monomers:
Mercury is used as a catalyst in the production of urethane foams and vinyl chloride monomers.
Used in Fungicides in Paints and Agriculture:
Mercury and its compounds have been used as fungicides in paints and agriculture.
Used in Medicines, Pigments, and Analytical Reagents:
Mercury compounds are used in medicines, pigments, and analytical reagents.
Used in Mercury Arc Lamps Producing Ultraviolet Rays:
Mercury is used in mercury arc lamps that produce ultraviolet rays.
Used in Mercury Boilers:
Mercury is used in mercury boilers for various applications.
Used in Manufacture of All Mercury Salts, Mirrors:
Mercury is used in the manufacture of all mercury salts and mirrors.
Used as a Catalyst in Oxidation of Organic Compounds:
Mercury is used as a catalyst in the oxidation of organic compounds.
Used in Extracting Gold and Silver from Ores:
Mercury is used in the extraction of gold and silver from ores.
Used in Making Amalgams, Electric Rectifiers, Mercury Fulminate:
Mercury is used in the production of amalgams, electric rectifiers, and mercury fulminate.
Used in Dentistry:
Mercury is used in dentistry for various applications.
Used in Determining Nitrogen by Kjeldahl Method, for Millon's Reagent:
Mercury is used in determining nitrogen by the Kjeldahl method and for Millon's reagent.
Used as Cathode in Electrolysis, Electroanalysis:
Mercury is used as a cathode in electrolysis and electroanalysis.
Used in Pharmaceuticals, Agricultural Chemicals, Anti-Fouling Paints:
Mercury is also used in pharmaceuticals, agricultural chemicals, and anti-fouling paints.
History
Although mercury is known from early times and was used by alchemists, its first modern scientific applications date back to 1643 when Torricelli used it in the barometer to measure pressure and about eight decades later Fahrenheit used it in the thermometer to measure temperature. Before this, mercury’s use was confined to decorative work, gold extraction and medicines. The element was named after the planet mercury and its symbol Hg is taken from the Latin word hydrargyrum, which means liquid silver.
The element does not occur in nature in native form. Its principal mineral is cinnabar, the red mercuric sulfide, HgS. Black mercuric sulfide, metacinnabar, also is found in nature. Other ores are livingstonite, HgSb4S7; coloradite, HgTe; tiemannite, HgSe; and calomel, HgCl. Its concentration in the earth’s crust is estimated to be 0.08 mg/kg. The average concentration in sea water is about 0.03 μg/L.
History
The name of Hg derives from the Roman god “Mercury”, the nimble messenger of the gods, since the ancients used that name for the element, which was known from prehistoric times. The name mercury originated in 6th-century alchemy, in which the symbol of the planet was used to represent the metal; the chemical symbol Hg derives from the Latin hydrargyrum, “liquid silver or quick silver.” Although its toxicity was recognized at an early date, its main application was for medical purposes.
Production Methods
Mercury mostly is obtained from its sulfide ore, cinnabar. The process involves roasting cinnabar in a furnace between 600 to 700°C. Mercury vapors are cooled and condensed into metal:
HgS + O2 → Hg + SO2
Mercury may also be extracted from cinnabar by reduction of the ore with lime at elevated temperature:
4HgS + 4CaO → 4Hg + 3CaS + CaSO4
Smaller quantities of metal are recovered from mercury-containing industrial and municipal wastes, such as amalgams and batteries. The scrap material is heated in a retort and the vapors of mercury are condensed into highpurity metal.
Production Methods
Mercury is mined primarily in underground mines as the
metal or as the red sulfide cinnabar (HgS). Like HgO, the
sulfide decomposes at higher temperatures. Heating of the ore and condensation of the mercury vapor constitute a
convenient procedure for reducing, extracting, and purifying
mercury from its ore. In the United States, mercury is
produced primarily from secondary sources; this involves
recycling a variety of industrial waste products. A survey in
1980 conducted by the U.S. National Institute for Occupational
Safety and Health suggested that about 70,000 workers
were exposed to mercury and its compounds; the majority of
these exposures involves mercury vapor. However, this number
has probably already decreased considerably, and occupational
mercury vapor exposure has now become fairly rare
in industrialized countries. On the other hand, numbers of
workers exposed to mercury vapor from informal mining in
developing countries has increased disproportionally and is
causing health risks to workers and their families, including
children.
Toxicity
Elemental mercury and all its compounds are highly toxic by all routes of exposure. The element has significant vapor pressure at ambient temperatures (0.0018 torr at 25°C) that can produce severe inhalation hazard. The symptoms from short exposure to high concentration of mercury vapors are bronchitis, coughing, chest pain, respiratory distress, salivation and diarrhea (Patnaik, P. 1999. A Comprehensive Guide to the Hazardous Properties of Chemical Substances, 2nd ed., New York: John Wiley and Sons). Other symptoms are tremor, insomnia and depression. Mercury can cause damage to kidney, liver, lungs and brain. Organomercury compounds and inorganic salt solutions can be absorbed into the body through skin contact and cause severe poisoning. It accumulates as Hg2+ in the brain and kidneys. US EPA has classified mercury as one of the priority pollutant metals in environmental matrices.
Reactivity Profile
MERCURY forms an explosive acelylide when mixed with acetylene. Can form explosive compounds with ammonia (a residue resulting from such a reaction exploded when an attempt was made to clean MERCURY off a steel rod [Chem. Eng. News 25:2138. 1947]. Chlorine dioxide (also other oxidants, such as: chlorine, bromine, nitric acid, performic acid), and MERCURY explode when mixed [Mellor 2, Supp. 1:381. 1956]. Methyl azide in the presence of MERCURY is potentially explosive [Can. J. Chem. 41:1048. 1963]. Ground mixtures of sodium carbide and MERCURY can react vigorously [Mellor 5:848. 1946-47]. Ammonia forms explosive compounds with gold, MERCURY, or silver. (Eggeman, Tim. mmonia Kirk-Othmer Encyclopedia of Chemical Technology. John Wiley & Sons, Inc. 2001.).
Hazard
Central nervous system impairment,
peripheral nervous system impairment, and kidney damage. (1) Mercury, metallic: Highly toxic
by skin absorption and inhalation of fume or vapor,
absorbed by respiratory and intestinal tract. FDA
permits zero addition to
Health Hazard
Mercury is a non-specific toxin, attacking many of the body s systems. At low levels of exposure, symptoms are mainly related to nerve and brain function and include memory loss, mood instability, tremor, and other stress-like symptoms: poor coordination, headache, and visual and hearing problems. Recently, reproductive health has been shown to be affected, with abnormalities in menstrual cycle, poor outcome of pregnancy, and subfertility in both men and women. The immune system is also damaged by mercury exposure.
Fire Hazard
Behavior in Fire: Not flammable
Flammability and Explosibility
Mercury is not combustible.
Safety Profile
Poison by inhalation.
Human systemic effects by inhalation:
wakefulness, muscle weakness, anorexia,
headache, tinnitus, hypermotihty, darrhea,
liver changes, dermatitis, fever. An
experimental teratogen. Experimental
reproductive effects. Questionable carcinogen with experimental tumorigenic
data. Human mutation data reported. Used
in dental applications, electronics, and
chemical synthesis.
bromopropyne, alkynes + silver perchlorate,
ethylene oxide, lithium, methylsilane +
oxygen (explodes when shaken), peroxyformic acid, chlorine dioxide, tetracarbonylnickel + oxygen. May react with ammonia to
form an explosive product. Mixtures with
methyl azide are shockand spark-sensitive
explosives. The vapor iptes on contact
with boron diiodophosphide. Reacts
violently with acetylenic compounds (e.g.,
acetylene, sodmm acetylide, 2-butyne-l,4
do1 + acid), metals (e.g., aluminum, calcium,
potassium, sodium, rubidium, exothermic
formation of amalgams), Cl2, ClO2, CH3N3,
NazCz, nitromethane. Incompatible with
methyl azide, oxidants. When heated to
decomposition it emits toxic fumes of Hg.
See also MERCURY COMPOUNDS.
Potential Exposure
Mercury is used as a catalyst, in dental
applications; and in pharmaceuticals; as a liquid cathode in
cells for the electrolytic production of caustic and chlorine.
It is used in electrical apparatus (lamps, rectifiers, and batteries) and in control instruments (switches, thermometers,
and barometers)
Carcinogenicity
There is no conclusive evidence from epidemiological
studies that mercury increases
cancer risk in humans.12 In the few studies in
which increases have been reported, concomitant
exposure to other known carcinogens has
confounded the results. The IARC has determined
that there is inadequate evidence in
humans for the carcinogenicity of mercury and
mercury compounds.12 In animals there is inadequate
evidence for carcinogenicity of metallic
mercury and limited evidence for the carcinogenicity
of mercuric chloride.
Environmental Fate
Mercury cycles through various environmental phases by exchange from ground to air and back again. Metallic and dimethylmercury, which are volatile, will be released as mercury vapor that can travel long distances before being redeposited. When found in surface waters and soils it will degas into the surrounding air where natural currents and winds spread the materials until they are deposited back on the surface waters and soils. The majority of mercury returned to the soil or water is by wet partition and accounts for almost all of the mercury found in lakes with no other input source. Inert mercury will deposit bound to particulates in aerosols. Once deposited, mercury must adsorb to soil or sediment particulates or be returned to the atmosphere. This cycle continues with a portion of the mercury revolatilizing into the atmosphere in each cycle.
storage
Precautions should be taken to prevent spills of mercury because
drops of the liquid metal can easily become lodged in floor cracks, behind cabinets, and
equipment, etc., with the result that the mercury vapor concentration in the laboratory may
then exceed the safe and allowable limits. Containers of mercury should be kept tightly sealed
and stored in secondary containers (such as a plastic pan or tray) in a well-ventilated area.
When breakage of instruments or apparatus containing significant quantities of Hg is possible,
the equipment should be placed in a plastic tray or pan that is large enough to contain the
mercury in the event of an accident. Transfers of mercury between containers should be
carried out in a fume hood over a tray or pan to confine any spills.
Shipping
UN2809 Mercury, Hazard class: 8; Labels:
8-Corrosive material, 6.1-Poisonous material
Purification Methods
After air has been bubbled through mercury for several hours to oxidise metallic impurities, it is filtered to remove coarser particles of oxide and dirt, then sprayed through a 4-ft column containing 10% HNO3. It is washed with distilled water, dried with filter paper and distilled under vacuum. [Schenk in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I p8 1963.]
Toxicity evaluation
Mercury has a great affinity for sulfhydryl moieties and, hence,
binds and inactivates a variety of enzymes. Methylmercury also
initiates lipid peroxidation, which can produce alterations in
cell membranes. Mercury damages the microtubules in the
brain by reacting with the protein tubulin.
Incompatibilities
Heating mercury causes the formation of
toxic mercury oxide fumes. Reacts violently with alkali
metals; acetylene, azides, ammonia gas; chlorine, chlorine
dioxide; many acids; most metals; ground mixtures of
sodium carbide, and ethylene oxide. Contact with methyl
azide forms shock- and spark-sensitive explosives. Attacks
copper and many other metals, forming amalgams
Waste Disposal
Consult with environmental
regulatory agencies for guidance on acceptable disposal
practices. Generators of waste containing this contaminant
(≥100 kg/mo) must conform to EPA regulations governing
storage, transportation, treatment, and waste disposal.
Accumulate for purification and re-use if possible. Mercury
vapors may be adsorbed or treated with sulfide solutions
and then sent to mercury recovery operations
Check Digit Verification of cas no
The CAS Registry Mumber 7439-97-6 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 7,4,3 and 9 respectively; the second part has 2 digits, 9 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 7439-97:
(6*7)+(5*4)+(4*3)+(3*9)+(2*9)+(1*7)=126
126 % 10 = 6
So 7439-97-6 is a valid CAS Registry Number.
InChI:InChI=1/Hg
