Soap

Description

A water-dispersible cleansing product. Soaps are produced by the saponification reaction of long chain fatty acids, such as found in oils and fats, with an alkali, such as sodium hydroxide or lye. Soaps made from animal fat and wood ashes have been used since antiquity. Although soap was made at home for laundry purposes from the European Middle Ages to early modern times, cake soap was a luxury product that came into common use only in the 19th century. Many soaps have an alkaline pH that can shrink wool and cause acid dyes to bleed. Alkaline soaps can also cause yellowing and brown stains on white cellulosic fibers (King 1985). Additionally, soaps can dull colors and form insoluble residues with hard water minerals. About 1968, numerous synthetic detergents were developed that have largely replaced soaps for cleaning textiles and other materials.

Synonyms and Related Terms

savons (Fr.)

Other Properties

Usually has a pH of 9-10

Hazards and Safety

May cause acid dyes to run. Forms insoluble residues with hard water minerals such as calcium carbonate.

Additional Information

R. King, Textile Identification, Conservation and Preservation, Noyes Publications, Park Ridge, NJ, 1985

Sources Checked for Data in Record

• Hoechst Celanese Corporation, Dictionary of Fiber & Textile Technology (older version called Man-made Fiber and Textile Dictionary, 1965), Hoechst Celanese Corporation, Charlotte NC, 1990

• Hermann Kuhn, Conservation and Restoration of Works of Art and Antiquities, Butterworths, London, 1986

• Rosalie Rosso King, Textile Identification, Conservation, and Preservation, Noyes Publications, Park Ridge, NJ, 1985

• Richard C. Wolbers, Nanette T. Sterman, Chris Stavroudis, Notes for Workshop on New Methods in the Cleaning of Paintings, J.Paul Getty Trust, Los Angeles, 1990

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 731

• Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998

• Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000