9037. Talc

Nomenclature

CAS number: 14807-96-6
Talcum; French chalk.

Description and references

The lumps are also known as soapstone or steatite. Finely powdered native hydrous magnesium silicate. Comprehensive description: A. W. Newman et al., Anal. Profiles Drug Subs. Excip. 23, 511-542 (1994).

Properties

White to grayish-white, very fine odorless, crystalline powder; unctuous, and adheres readily to the skin. Insol in water, cold acids or in alkalies. Sol in hot concentrated phosphoric acid.

Caution

Potential symptoms of overexposure to talc containing no asbestos and less than 1% quartz are fibriotic pneumoconiosis; irritation of eyes. Potential symptoms of overexposure to soapstone containing less than 1% quartz are pneumoconiosis; cough, dyspnea; digital clubbing; cyanosis; basal crackles, cor pulmonale. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 292, 280.

Use

Dusting powder, either alone or with starch or boric acid, for medicinal and toilet prepns; excipient and filler for pills, tablets and for dusting tablet molds; clarifying liquids by filtration. As pigment in paints, varnishes, rubber; filler for paper, rubber, soap; in fireproof and cold-water paints for wood, metal and stone; lubricating molds and machinery; glove and shoe powder; electric and heat insulator.