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.

---

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

---

Etymology

Origin of bleaching powder

First recorded in 1850–55

Example Sentences

See Examples For:

bleaching powder

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

The excretions of the bowels or kidneys should be treated with bleaching powder.

From The New Gresham Encyclopedia Volume 4, Part 1: Deposition to Eberswalde by Various

But already in the year 1834 the German chemist Runge noticed that one of the products obtained by distilling coal-tar, namely, aniline, gave a bright blue coloration under the influence of bleaching powder.

From Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 8 "Dubner" to "Dyeing" by Various

It is used in the preparation of ammonia, bleaching powder, and potassium hydroxide.

From An Elementary Study of Chemistry by William McPherson