bio·​haz·​ard ˈbī-ō-ˌha-zərd How to pronounce biohazard (audio)
: a biological agent or condition that is a hazard to humans or the environment
also : a hazard posed by such an agent or condition

Examples of biohazard in a Sentence

The gasoline spill created a serious biohazard.
Recent Examples on the Web In case of biohazards, flight attendants have protocols to follow from OSHA, the Occupational Safety and Health Administration. Natalie B. Compton, Andrea Sachs and Heidi Pérez-Moreno, The Washington Post, Anchorage Daily News, 7 Sep. 2023 The world needs better ways to monitor all manner of biohazards, including organisms engineered by terrorists or accidentally leaked from a lab. Globe Staff,, 8 Aug. 2023 So, what constitutes a biohazard significant enough to reroute a plane? Erin Clements, Peoplemag, 8 Sep. 2023 The competition is run by Aftermath Services, a trauma cleaning and biohazard removal company that responds to deaths, crime scenes, biohazards and COVID-19. Morgan Womack, The Indianapolis Star, 31 May 2023 The fluid is also considered a potential biohazard. Joanna Thompson, Scientific American, 22 Aug. 2023 Story continues below advertisement Advertisement Hawkins, of Miriam’s Kitchen, said that beyond occupying a city park or being near a school, other reasons city officials have given her for the emergency sweeps include correcting a sidewalk obstruction or clearing biohazards. Marissa J. Lang, Washington Post, 26 June 2023 Those include trash and biohazard collection in city parks, landscaping, street and sidewalk cleaning and graffiti removal on some public properties. oregonlive, 2 Feb. 2023 In one scene, a health official wearing a yellow biohazard suit bullies the grieving families of the monster's initial victims while deflecting their questions about why they're being put into quarantine. Jeremy Hsu, Discover Magazine, 30 June 2015 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'biohazard.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1965, in the meaning defined above

Time Traveler
The first known use of biohazard was in 1965

Dictionary Entries Near biohazard

Cite this Entry

“Biohazard.” Dictionary, Merriam-Webster, Accessed 9 Dec. 2023.

Medical Definition


bio·​haz·​ard ˈbī-ō-ˌhaz-ərd, -ˈhaz- How to pronounce biohazard (audio)
: a biological agent or condition (as an infectious organism or insecure laboratory procedures) that constitutes a hazard to humans or the environment
also : a hazard posed by such an agent or condition
biohazardous adjective
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