bleaching powder

American  

noun

Chemistry.

1. a white powder that decomposes on contact with water and has the characteristic odor of gaseous chlorine: regarded, when dry, as a mixed calcium hypochlorite-chloride, used as a commercial bleach for wood pulp, textiles, oils, and soaps, and in laundering as a decolorizer and disinfectant.

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bleaching powder British  

noun

1. Also called: chloride of lime.   chlorinated lime.  a white powder with the odour of chlorine, consisting of chlorinated calcium hydroxide with an approximate formula CaCl(OCl).4H 2 O. It is used in solution as a bleaching agent and disinfectant

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Etymology

Origin of bleaching powder

First recorded in 1850–55

Example Sentences

According to eyewitnesses, the chemical warehouse stored bleaching powder, plastic and hydrogen peroxide, all of which can intensify fires.

From BBC • Oct. 14, 2025

Victims of mustard gas must have their clothes carefully removed, must be "decontaminated" with soap, clean water and sodium bicarbonate, rubbed with a paste of bleaching powder and water, successful antidote for the oily gas.

From Time Magazine Archive

Both patents are based on the same discovery �that wool becomes unshrinkable when soaked in tertiary amyl or butyl hypochlorite, chemicals related to bleaching powder.

From Time Magazine Archive

Chemical disinfectants in milk: bleaching powder, 81; corrosive sublimate, 81; formalin, 80; sulfur, 80; whitewash, 81; vitriol, 81.

From Outlines of Dairy Bacteriology, 8th edition A Concise Manual for the Use of Students in Dairying by Russell, H. L. (Harry Luman)

L. Eisner recognized, in 1846, the part played by the atmosphere, and in 1879 Dixon showed that bleaching powder, manganese dioxide, and other oxidizing agents, facilitated the solution.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 2 "Gloss" to "Gordon, Charles George" by Various