trihalomethane

noun tri·halo·meth·ane \ (ˌ)trī-ˌha-lə-ˈme-ˌthān , British usually -ˈmē- \

|Updated on: 19 Aug 2018

Definition of trihalomethane

: any of various derivatives CHX₃ of methane (such as chloroform) that have three halogen atoms per molecule and are formed especially during the chlorination of drinking water

Recent Examples of trihalomethane from the Web

In Dos Palos, where the water contains potentially harmful chemicals known as trihalomethanes, Joaquin Garcia has 5-gallon jugs of clean water delivered to his home.

— dale kasler, phillip reese and ryan sabalow, sacbee, "360,000 Californians have unsafe drinking water. Are you one of them?," 1 June 2018
And not only lead, but trihalomethane (TTHM) – a chemical byproduct of chlorine disinfectant.

— richard horan, The Christian Science Monitor, "'The Poisoned City' tells the horrific story of Flint's contaminated water," 10 July 2018
Until several months ago, customers received notices on the back of their water bills stating that their water had been tested and found to be above federal limits of trihalomethanes and haloacetic acids.

— nadia kounang, CNN, "The Kentucky county where the water smells like diesel," 30 Mar. 2018
The quality of the city’s drinking water has been a hot-button issue since routine testing in Nov. 2016 revealed elevated levels of trihalomethane, a disinfectant by-product.

— brian ballou, Sun-Sentinel.com, "Castillo re-elected in Pines, Monroig out," 12 Mar. 2018
Unhealthy levels of trihalomethanes, or TTHMs, were reported by water utility companies in Wellington, Munroe Falls and Ravenna.

— james f. mccarty, cleveland.com, "Contaminants taint some NE Ohio water, but EPA says safe to drink," 20 Oct. 2017
The total trihalomethanes group includes four chemicals: chloroform, bromodichloromethane, dibromochloromethane and bromoform.

— jennifer larino, NOLA.com, "What is in your water? See test results for 19 New Orleans-area utilities," 3 Aug. 2017
The water also contains trihalomethanes at levels well below federal regulatory standards, but above a health guideline standard.

— keith matheny, Detroit Free Press, "Millions in Michigan exposed to potentially unsafe chemicals in their water," 26 July 2017
And then there’s a group of four cancer-causing chemicals called trihalomethanes that form when organic matter in the water reacts with chemicals used to disinfect it.

— david fleshler, Sun-Sentinel.com, "Check online for contaminants in your city's drinking water," 26 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'trihalomethane.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of trihalomethane

1968

in the meaning defined above

See Words from the same year

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Medical Dictionary

trihalomethane

noun tri·halo·meth·ane \ (ˌ)trī-ˌhā-lə-ˈmeth-ˌān, British usually -ˈmē-ˌthān \

medical Definition of trihalomethane

: any of various derivatives CHX₃ of methane (as chloroform) that have three halogen atoms per molecule and are formed especially during the chlorination of drinking water —abbreviation THM