10147. Zinc Oxide

Nomenclature

CAS number: 1314-13-2
Flowers of zinc; philosopher's wool; zinc white; C.I. Pigment White 4; C.I. 77947.
OZn; mol wt 81.41.
O 19.65%, Zn 80.35%.
ZnO.

Description and references

Occurs as the mineral zincite. Prepd by vaporization of metallic zinc and oxidation of the vapors with preheated air (French process); also from franklinite, (American process) or from zinc sulfide: Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience, New York, 4th ed., 1975) pp 882-888. Purification: Depew, US 2372367 (1945 to American Zinc, Lead & Smelting). The medicinal grade contains 99.5% or more ZnO; technical grades contain 90-99% ZnO and a few tenths of 1% of lead. See also: Colour Index vol. 4 (3rd ed., 1971) p 4687. Efficacy as sunblock: S. R. Pinnell et al., Dermatol. Surg. 26, 309 (2000).

Properties

White or yellowish-white, odorless powder. Hexagonal crystals: d 5.67. Also reported as d420 5.607. Sublimes at normal pressure. nD 2.0041, 2.0203. American process zinc oxide pH 6.95. French process zinc oxide pH 7.37. Practically insol in water. Sol in dil acetic or mineral acids, ammonia, ammonium carbonate, fixed alkali hydroxide solns.

Caution

Potential symptoms of overexposure are metal fume fever (chills, muscle aches, nausea, fever, dry throat, cough, weakness, lassitude); metallic taste; headache; blurred vision; low back pain; vomiting; fatigue; malaise; tight chest, dyspnea, rales, decreased pulmonary function. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 338.

Derivative

Calamine.

Nomenclature

Eczederm (Quinoderm).

Description and references

Zinc oxide with a small proportion of ferric oxide as a coloring agent.

Properties

Pink powder. Insol in water. Almost completely sol in mineral acids.

Use

As pigment in white paints instead of lead carbonate; in cosmetics, driers, quick-setting cements; with syrupy phosphoric acid or ZnCl2 in dental cements; manuf opaque glass and certain types of transparent glass; manuf enamels, automobile tires, white glue, matches, white printing inks, porcelains, zinc green; as a reagent in analytical chemistry; in electrostatic copying paper; as flame retardant; in electronics as semiconductor.

Therapeutic Category

Astringent; topical protectant; ultraviolet screen.

Therapeutic Category (Veterinary)

Antiseptic; astringent; topical protectant.

Keywords

Astringent; Topical Protectant; Ultraviolet Screen