hydroquinone

American  

[hahy-droh-kwi-nohn, -druh-kwin-ohn] / ˌhaɪ droʊ kwɪˈnoʊn, -drəˈkwɪn oʊn /

noun

Chemistry.

1. a white, crystalline compound, C 6 H 6 O 2 , formed by the reduction of quinone: used chiefly in photography and to inhibit autoxidation reactions.

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hydroquinone British  

/ ˌhaɪdrəʊˈkwɪnɒl, ˌhaɪdrəʊkwɪˈnəʊn /

noun

1. Also called: quinol.  a white crystalline soluble phenol used as a photographic developer; 1,4-dihydroxybenzene. Formula: C 6 H 4 (OH) 2

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Etymology

Origin of hydroquinone

First recorded in 1860–65; hydro- ¹ + quinone

Example Sentences

Other sellers admitted using regulated ingredients such as kojic acid, hydroquinone and a powerful antioxidant, glutathione, which may cause rashes and other side-effects.

From BBC • Mar. 23, 2025

You can’t talk about hyperpigmentation treatments without mentioning hydroquinone — a controversial depigmenting agent that can bleach dark patches on the skin — which has been used for more than 40 years to treat hyperpigmentation.

From Washington Post • Jun. 20, 2021

Clay tries to educate patients that there are alternative ingredients to hydroquinone such as cyspera, azelaic acid and kojic acid.

From Washington Post • Jun. 20, 2021

Most of the smuggled cosmetics tend to be skin-lightening creams that were banned in Uganda in 2016 because they contain mercury and hydroquinone, which some studies have linked to damaging health side-effects.

From BBC • Jan. 8, 2020

When technical sodium dichromate is used, the solution should be filtered with suction, before it is added to the hydroquinone, in order to remove any insoluble impurities.

From Organic Syntheses by Conant, James Bryant