Bleaching agent

Description

A solution or additive used to lighten or whiten another material. Bleaching agents are usually chemicals that oxidize or reduce impurities and colorants in the treated material. Sun exposure has been used since ancient times in Egypt, China and the Middle East to bleach fibers and fabrics. In the 18th century, solutions of Potash, Lye, or Sulfuric acid were used for bleaching. The whitening properties of chlorine products were published in 1789 by French chemist Claude Berthollet. In 1799, the Scottish scientist, Charles Tennant, introduced a dry mixture chlorine and Slaked lime called Bleaching powder. It was the primary bleaching agent until 1925 when liquid chlorine bleaches (Sodium hypochlorite) were introduced. See Oxidizing bleach, Reducing bleach, and Optical bleach.

Synonyms and Related Terms

bleach; chloramine T; Clorox; ammonia; oxalic acid; chlorine dioxide; formaldehyde; hydrogen peroxide; potassium metabisulfite; sodium chlorate; sodium chlorite; sodium hypochlorite; sodium peroxide; sodium perborate; sodium bisulfite; sodium borohydride; peracetic acid

Risks

• Most bleaches are toxic by ingestion and will cause irritation on skin contact.
• Chlorine bleaches will release highly toxic chlorine gas when mixed with acids, ammonia or when heated.

Resources and Citations

• B.K.Easton, "Textile Bleaching in the U.S." Ciba-Geigy Review 3:2-32, 1971.

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

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

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

• Tom Rowland, Noel Riley, A-Z Guide to Cleaning, Conserving and Repairing Antiques, Constable and Co., Ltd., London, 1981

• Boise Cascade Paper Group, The Paper Handbook, Boise Cascade, Portland OR, 1989

• Michael McCann, Artist Beware, Watson-Guptill Publications, New York City, 1979

• Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982

• Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996

• 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

• Encyclopedia Britannica, http://www.britannica.com Comment: "Bleach." Accessed 7 Sept. 2004. Claude Berthollet discovered bleaching with chlorine in 1785.

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

• Judith H. Hofenk de Graaff, The Colourful Past: Origins, Chemistry, and Identification of Natural Dyestuffs, Archetype, London, 2004 Comment: Claude Berthollet published his work in 1789 on the bleaching effect of chlorine