Nomenclature
CAS number: 1333-82-0
Chromium oxide (CrO
3); chromic anhydride; chromium trioxide.
CrO
3; mol wt 99.99.
Cr 52.00%, O 48.00%.
Description and references
Produced commercially by the action of concd
H2SO4 on a soln of chromate or dichromate: Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience, New York,
4th ed., 1975) pp 270-274.
Properties
Dark red, deliquesc bipyramidal prismatic crystals,
flakes or granular power. d 2.70. mp 197°.
Dec at 250° to Cr2O3 and O2. Very
sol in water; sol in H2SO4. Powerful oxidizer;
oxidizes alcohol and most other organic substances, sometimes with
dangerous violence. Contact with combustible
material may cause fire.Caution
Potential symptoms of overexposure
are respiratory system irritation, nasal septum perforation; liver
and kidney damage; leukocytosis, leukopenia, monocytosis, eosinophilia;
eye injury, conjunctivitis; skin ulcers, sensitization dermatitis.
See NIOSH Pocket Guide to Chemical
Hazards (DHHS/NIOSH 97-140, 1997) p 70. Chronic overexposure
may lead to severe liver damage, CNS involvement and lung cancer.
See Clinical Toxicology of Commercial
Products, R. E. Gosselin et al., Eds. (Williams
& Wilkins, 5th ed., 1984) Section II, p 108. See also Patty's Industrial Hygiene and Toxicology vol. 2C, G. D. Clayton, F. E. Clayton, Eds. (Wiley-Interscience,
New York, 4th ed., 1994) p 1973-1985. Chromium hexavalent compounds
are listed as known human carcinogens: Report
on Carcinogens, Eleventh Edition (PB2005-104914, 2004)
p III-63.Use
Chromium plating; copper stripping; aluminum anodizing;
corrosion inhibitor; photography; purifying oil and acetylene; hardening
microscopical prepns; oxidizing agent in organic chemistry.
Therapeutic Category (Veterinary)
Has been used in solution as a topical
antiseptic and astringent.