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Le Thallium
(technologie),
Oxyde de
Thallium (III) - Toxicologie, Thallium (technology), Thallium
Oxide (III) - Toxicology
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THALLIUM
by
Smart.Conseil
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- Characteristics :
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- The characteristics of
Thallium resemble those of heavy metals like lead. It
is especially employed in optical glassmaking for its
very high index of refraction which it confers onto
the glass (even higher than that of lead glasses), one
also uses it in jewellery for this same reason. Just
like lead, it gives high density glasses , its atomic
weight is 204.37g (compared to 207.2 for Pb). Thallium
is at the same monovalent and trivalent. Between 800
and 1100°C, the oxide Tl2O3 dissociates to give
of Tl2O, even under the effect of a strongly oxidizing
composition, its valence is thus rather difficult to
control.
- Just as lead, Thallium can
form a continuous vitreous network in the presence of
small quantities of silica. But contrary to lead, the
formation of Tl2O-SiO2 binary glasses is less wide. It
ceases near 60% Tl2O (molar), whereas for this value
glasses with lead-silica are still very stable. It
results that glasses with a high content of Tl2O are
opacified by the effect of the separation of
nonmiscible phases.
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- Technology :
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- In the production process of
Thallium glasses, this element is introduced in the
form of oxide compounds (as in the production of lead
glasses) with low melting point generally below
800°C.
- Thallium and its compounds
are powerful poisons such as lead and arsenic.
Thallium affects the nervous system, the digestive
tract and the kidneys. The loss of hair is typical of
poisoning by Thallium.
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- Effects on the
properties of glasses :
- Density : the density of glasses strongly
increases with Thallium, more than with lead under the
same conditions. Thermal dilation coefficient
: It increases with
an increasing Thallium content , whereas viscosity,
the point of transformation and of softening decrease.
As for lead glasses, glasses with Thallium become more
abrasion resistant if the Thallium content
increases.
- Chemical resistance
: It strongly falls
with the increase in the Thallium content.
- Optical properties
: It is on this point
that the properties of Thallium are most interesting.
As for lead glasses or those with bismuth, glasses
with Thallium have a high index of refraction (more
than those with lead).
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- Reference : Chemical
Approach to Glass, by Milos .B Volf, Elsevier
1984.
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- Smart.Conseil © July
2004-07-11
- http://perso.wanadoo.fr/smart2000/
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THALLIUM Oxide (III)
by
Edouard Bastarache
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- Introduction
:
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- Formula : Tl2O3
- CAS # : 1314-32-5
- Insoluble in water.
-
- Uses :
- Thallium oxide has been used
to produce glasses with a high index of refraction.
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- Toxicology
:
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- I-Routes of Entry :
- Inhalation,
- Skin,
- Ingestion.
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- II-Effects of Exposure
:
- To the best of our knowledge
the acute and chronic toxicity of this substance
- is not fully known.
- Oral Lethal Dose Fifty
(LD50) = 44 mg/kg (rat)
- The main symptoms of
thallium poisoning are peripheral neuropathy and loss
of hair.
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- A-Acute Effects
:
- -paresthesias,
- -ataxia,
- -alopecia,
- -fever,
- -coryza,
- -abdominal pain,
- -nausea,
- -vomiting,
- -lethargy,
- -speech disorders,
- -tremors,
- -cyanosis,
- -convulsions,
- -pulmonary oedema,
- -bronchopneumonia,
- -kidney, liver and brain
damage,
- -death.
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- B-Chronic Effects
:
- -alopecia,
- -salivation,
- -blue line on the
gums,
- -gastrointestinal, endocrine
system and kidney damage .
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- C-Inhalation :
- Inhalation of thallium will
cause irritation of mucous membranes and the
respiratory tract. Can cause pulmonary edema.
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- D-Ingestion :
- Ingestion of thallium
compounds can cause the effects described
above.
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- E-Skin :
- Strong skin irritant. Skin
contact may cause dermatitis on first contact.
- Thallium compounds can be
absorbed through the skin to cause effects described
above.
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- F-Eye :
- Strong eye irritant.
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- G-Medical Conditions
Generally Aggravated by Exposure :
- Lung disorders, liver and
kidney damage.
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- Pregnancy
:
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- Thallium poisoning during
the first trimester of pregnancy can cause skeletal
deformations, alopecia, low birth weight and premature
birth.
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- Carcinogenicity :
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- Thallium oxide is not
considered carcinogenic by most of official
bodies.
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- Emergency
and First Aid Procedures :
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- I-General Information
:
- Immediately remove any
clothing soiled by the product.
- Remove breathing apparatus
only after contaminated clothing has been completely
removed.
- In case of irregular
breathing or respiratory arrest provide artificial
respiration
- II-Inhalation
:
- Supply fresh air. If
required, provide artificial respiration. Keep patient
warm.
- Seek immediate medical
advice.
- III-Ingestion
:
- Do not induce vomiting;
immediately call for medical help.
- Seek immediate medical
advice.
- IV-Skin :
- Brush off material, wash
affected area thoroughly with soap and water, and wash
contaminated clothing before reuse. Seek medical
advice.
- V-Eyes :
- Flush with copious amounts
of water, including under eyelids, for at least 15
minutes. Seek medical attention.
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- Reactivity
Data :
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- I-Stability
:
- Stable
- II-Conditions to Avoid
:
- Moisture
- III-Incompatibility
(Materials to Avoid) :
- Acids
- IV-Hazardous
Decomposition Products :
- Toxic thallium fumes.
- V-Hazardous
Polymerization :
- Will not occur.
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- Spill or
Leak Procedures :
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- I-Steps to Be Taken in
Case Material Is Released or Spilled :
- Isolate area, wear
appropriate protective equipment. Carefully
scoop
- up material, vacuum powder
using HEPA filter, avoid raising dust. Thoroughly
clean spill area.
- II-Waste Disposal Method
:
- Dispose of in accordance
with State, Federal and Local regulations.
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- Special
Protection Information :
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- I-General Protective and
Hygienic Measures :
- The usual precautionary
measures for handling chemicals should be followed.
- Keep away from foodstuffs,
beverages and feed.
- Remove all soiled and
contaminated clothing immediately.
- Wash hands before breaks and
at the end of work.
- Store protective clothing
separately.
- II-Respiratory Protection
(Specify Type) :
- NIOSH approved full face
respirator with high efficiency filters.
- III-Ventilation
:
- Use local exhaust to
maintain concentration at low exposure levels. General
exhaust is not recommended.
- IV-Protective Gloves
:
- Neoprene or nitrile
protective gloves
- V-Eye Protection :
- Approved non-vented safety
goggles
- VI-Other Protective
Equipment :
- Protective clothing to
prevent skin contact or clothing contamination.
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- Handling and
Storage :
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- I-Handling :
- A-Information for Safe
Handling :
- Keep container tightly
sealed.
- Store in cool, dry place in
tightly closed containers.
- Ensure good ventilation at
the workplace.
- Open and handle container
with care.
- B-Information about
Protection against Explosions and Fires :
- The product is not flammable
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- II-Storage
:
- A-Requirements to be Met
by Storerooms and Receptacles :
- No special requirements.
- B-Information about
Storage in One Common Storage Facility :
- Do not store together with
acids.
- C-Further Information
about Storage Conditions :
- Keep container tightly
sealed.
- Store in cool, dry
conditions in well sealed containers.
- Store under lock and key and
with access restricted to technical experts or their
assistants only.
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- Ecological
Information :
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- General Note
:
- Do not allow material to be
released to the environment without proper
governmental permits.
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- Special
Precautions :
-
- Precautions to Be Taken
in Handling and Storage :
- Wash thoroughly after
handling, keep container closed, thallium
compounds
- are extremely poisonous,
avoid all contact.
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- Disclaimer :
- The above information is
believed to be correct, but does not purport to be all
inclusive and shall be used only as a guide.
- The author shall not be held
liable for any damage resulting from handling or from
contact with the above product.
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-
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- References :
-
- 1-Occupational
Medicine,Carl Zenz, last edition.
- 2-Clinical Environmental
Health and Toxic Exposures, Sullivan & Krieger;
last edition.
- 3-Sax's Dangerous
Properties of Industrial Materials, Lewis C., last
edition.
- 4-Toxicologie
Industrielle et Intoxications Professionnelles,
Lauwerys R.R. last edition.
- 5-Chemical Hazards of the
Workplace, Proctor & Hughes, 4th
edition
- 6- Alfa Aesar, A Johnson
Matthey Company, MSDS, Thallium Oxide, June
2004
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