Zirconium Compounds Toxicity
By Edouard Bastarache
Introduction
:
Zirconium (Zr) constitutes about 0.2% of
the earth's crust, common minerals bind zircon, zirconium dioxide
and zirconates.
Uses :
- in alloys and metals used in nuclear
power, aerospace and various chemical industries;
- in the manufacture of ceramics, glass,
and porcelains;
- in the synthesis of pigments, dyes,
and water repellants;
- in tanning operations;
- in abrasive and polishing
materials
- as igniters in the manufacture of
munitions and detonators;
- in lighter flints;
- in skin ointments and
antiperspirants;
- as a "gas getter" in the manufacture
of high-vacuum tubes;
- as a deoxidizer, denitrifier and
desulfurizer in iron and steel manufacture
Typical Compounds
:
- zirconium hydride (ZrH2),
- zirconium oxide (ZrO2),
- zirconium oxychloride
(ZrOCl2.8H2O),
- zirconium silicate (ZrSiO2),
- zirconium tetrachloride
(ZrCl4),
- zirconyl acetate
(H2ZrO2(C2H3)2)2),
Occupational exposures
:
Potential occupational exposures to
zirconium may be encountered during :
- liberation from refining and casting
operations,
- preparation of alloys.
- In the manufacture of metal or
alloys.
Toxicology
:
Zirconium compounds are generally
considered to be of low toxicity.
Skin :
Granulomata have been produced by
repeated topical applications of zirconium salts to human skin.
Zirconium compounds are commonly used in
antiperspirants and thus sometimes cause granulomata of the
axillary skin. Aluminium zirconium compounds, which are mainly
used today, are considered to be safer in this regard.
Lungs :
Studies among workers exposed to
zirconium compounds fumes have failed to demonstrate adverse
pulmonary effects.
However, a recent report shows that
severe pulmonary fibrosis containing high concentrations of
several zirconium compounds occurred in a worker polishing and
blocking lenses in an optical company.
Eyes :
In my personal experience I have
encountered a corneal burn with a subsequent scar in a titanium
dioxide plant caused by the ocular projection of a small drop of
liquid zirconium sulfate at the place where it was introduced into
the process.
Quebec's exposure limit
:
VEMP (Valeur d'Exposition Moyenne
Pondérée) = 5mg/m³
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
Edouard Bastarache M.D.
Occupational & Environmental Medicine
Author of "Substitutions for Raw Ceramic Materials"
Tracy, Québec, CANADA
edouardb@sorel-tracy.qc.ca
http://www.sorel-tracy.qc.ca/~edouardb/
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