urushiol

American  

[oo-roo-shee-awl, -ol] / ʊˈru ʃiˌɔl, -ˌɒl /

noun

1. a toxic, liquid, catechol derivative, the active irritant principle in several species of the plant genus Rhus, as in poison ivy.

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urushiol British  

/ uːˈruː-, ˈuːrʊʃɪˌɒl /

noun

1. a poisonous pale yellow liquid occurring in poison ivy and the lacquer tree

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urushiol Scientific  

/ -ro̅o̅′shē-ôl′,-ōl′ /

1. A toxic substance present in the resin or on the surface of plants of the genus Rhus (syn. Toxicodendron). Urushiol is a mixture of several derivatives of catechol and is the irritating substance in poison ivy.

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Etymology

Origin of urushiol

1910–15; < Japanese urushi lacquer + -ol ¹

Example Sentences

The oily substance it contains, urushiol, tends to cause more intense reactions over time and it affects up to 90 percent of people.

From National Geographic • Apr. 18, 2023

Mango skin contains a chemical called urushiol, which can cause an allergic reaction similar to that of poison ivy in some people.

From Salon • Sep. 10, 2022

Animal studies indicate that the response to urushiol has nothing to do with histamines—bodily chemicals involved in many allergic reactions—so antihistamines are useless.

From Scientific American • Sep. 20, 2021

If a contaminated object isn’t cleaned, the urushiol will remain lying in wait — it can still cause a rash after hours, days or even years.

From Washington Post • Sep. 10, 2021

Researchers also found that CO2 makes urushiol, the oil in poison ivy that causes the allergic reaction in humans, stronger.

From Salon • Jul. 29, 2021