Dictionary.com
Thesaurus.com

biohazard

American  
[bahy-oh-haz-erd] / ˈbaɪ oʊˌhæz ərd /

noun

  • biohazards
    plural
  1. a pathogen, especially one used in or produced by biological research.

  2. the health risk posed by the possible release of such a pathogen into the environment.


biohazard British  
/ ˌbaɪəʊˈhæzəd /

noun

  1. material of biological origin that is hazardous to humans

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

biohazard Scientific  
/ bī′ō-hăz′ərd /
  1. A biological agent, such as an infectious microorganism, that constitutes a threat to humans or to the environment, especially one produced in biological research or experimentation.


Other Word Forms

Derived Forms

Inflected Forms

Nouns


Etymology

Origin of biohazard

bio- + hazard


Explanation

A biohazard is a biological substance that's dangerous to people or the environment. Many biohazards are made of bacteria or other microorganisms. Some biohazards are an unintentional side effect of biologists working with or studying toxins or viruses. One common type of biohazard is medical waste — things like used syringes or other tools contaminated with human blood, bacteria, or other microorganisms. The word biohazard was first used around 1973, from the Greek bio-, "life," and hazard, from the Old French hasard, "game of chance."

Keep Reading on Vocabulary.com

Vocabulary lists containing biohazard

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

In March, BBC News NI spoke to a family from Limavady who had to move out of their home after heating oil thieves struck and turned the property into a "massive biohazard".

From BBC ● Sep. 9, 2026

“The City gave Lineage 45 days to remove the biohazard food waste; today is day 60 on the City’s timeline.”

From Los Angeles Times ● Aug. 30, 2026

Nurses and doctors wore biohazard suits and three layers of medical gloves when they entered his room, swabbing him for virus up his nostrils and in other sites like his eyelids twice a day.

From The Wall Street Journal ● May 12, 2026

In August there were 23 mostly minor assault reports, consistent with other months, but guards led to more biohazard and misconduct events reported, said Wright.

From Seattle Times ● Oct. 6, 2023

Today she might put on a biohazard space suit.

From "The Hot Zone" by Richard Preston

He stopped his own research and called for an international conference to discuss the “potential biohazards of recombinant DNA molecules.”

From Los Angeles Times ● Feb. 22, 2023

Police said Thursday the rental home would be cleared of “potential biohazards and other harmful substances” to collect evidence starting Friday morning.

From Washington Times ● Dec. 30, 2022

But science tells us that while young children may benefit from playing in the mud, for instance, the opposite is true of exposing them to lethal pathogens and other biohazards.

From Washington Post ● Dec. 15, 2022

Feces, needles, bloody rags and other biohazards contribute to health concerns.

From Seattle Times ● Oct. 27, 2021

Colonel David Huxsoll was an expert in biohazards, and this was the sort of situation he thought the Institute was prepared to handle.

From "The Hot Zone" by Richard Preston

Random Word

Spin the wheel and learn a new word!

Get a word

Vocabulary.com logo
by dictionary.com

Dictionary.com's Learning Companion

Go beyond just looking up words.
Remember them forever with VocabTrainer.

Start training