contaminant
This term describes an unwanted substance that compromises the purity or safety of a medium. It carries a strong negative connotation of pollution or corruption, often implying a risk to health, quality, or scientific integrity. In technical or medical settings, the word specifically refers to foreign particles or microorganisms that breach a sterile field. While a pollutant is typically associated with large-scale environmental damage, a contaminant is often viewed as a specific, localized impurity within a sample or a controlled environment.
Meanings
A substance that makes another substance impure, unclean, or unfit for use.
"The water supply was found to contain a dangerous chemical contaminant."
A biological agent, such as a bacterium or virus, that accidentally enters a sterile environment or a sample.
"The laboratory technician ensured that no external contaminant entered the petri dish during the experiment."