chlor·​pyr·​i·​fos | \-ˈpir-ə-fäs, -ˈpī-rə\

Definition of chlorpyrifos 

: a toxic crystalline organophosphate pesticide C9H11Cl3NO3PS that inhibits acetylcholinesterase and is used to control insect pests and ticks

Examples of chlorpyrifos in a Sentence

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The administrator began reversing the proposal to ban the neurotoxic pesticide chlorpyrifos, going against all credible scientific advice. Umair Irfan, Vox, "Scott Pruitt is leaving behind a toxic mess at the EPA," 6 July 2018 Did Pruitt set some kind of record for most outrageous sellout when the EPA balked at banning the toxic chemical chlorpyrifos, even after scientists had shown the substance is harmful to children? Will Bunch,, "Not caring about Pruitt's EPA scandals helps us not care that the planet is on fire | Will Bunch," 19 June 2018 During his tenure, the EPA turned down a petition to strengthen its ban on the controversial pesticide chlorpyrifos, which some scientists believe is linked to nervous system issues but its manufacturer has defended as safe. Gregory Wallace, CNN, "Who else wasn't at the EPA chemical meeting? The victims," 26 May 2018 In March, lawmakers in Maryland even tabled a bill to ban chlorpyrifos, a pesticide deemed unsafe by the Environmental Protection Agency some years ago, in anticipation of needing it to combat lanternflies in coming months. Zach Montague, New York Times, "Lanternflies Eat Everything in Sight. The U.S. Is Looking Delicious.," 21 May 2018 The ad singles out Pruitt’s decision to deny a petition to ban the agricultural use of the insecticide chlorpyrifos after the EPA’s own scientists concluded that exposure impedes brain development in infants and fetuses. Dino Grandoni, Washington Post, "The Energy 202: NAACP joins environmental groups in calling for Scott Pruitt's ouster," 18 Apr. 2018 Jackson told career staff to deny a petition seeking to ban chlorpyrifos, the controversial pesticide that has been shown to damage children’s brains. Emily Atkin, The New Republic, "How James Inhofe Snowballed the EPA," 23 Apr. 2018 One study, by researchers at Columbia University, found a connection between higher exposure levels to chlorpyrifos and learning and memory problems among farmworkers and children. Washington Post, "Scott Pruitt pushes back on finding that would restrict pesticides’ use to protect fish," 2 Feb. 2018 The argument, along with others from golf courses that use chlorpyrifos to fight a stubborn breed of weevil, won out in Annapolis, for now. Scott Dance,, "Fears of lanternfly invasion cause Maryland lawmakers to abandon pesticide ban," 15 Mar. 2018

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

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First Known Use of chlorpyrifos

1970, in the meaning defined above

History and Etymology for chlorpyrifos

chlor- + pyridine + -fos (alteration of phosphorus)

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The first known use of chlorpyrifos was in 1970

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chlor·​pyr·​i·​fos | \-ˈpir-ə-fäs, -ˈpī-rə- \

Medical Definition of chlorpyrifos 

: a toxic crystalline organophosphate pesticide C9H11Cl3NO3PS that inhibits acetylcholinesterase and is used to control insect pests and ticks

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