Contamination is the presence of a minor constituent in another chemical or mixture, often at the trace level. In chemistry, the term usually describes a single chemical, but in specialized fields the term can also mean chemical mixtures, even up to the level of cellular materials.
All chemicals contain some level of contamination. Contamination may be recognized or not and may become an issue if the contaminated chemical is mixed with other chemicals or mixtures and causes additional chemical reactions. The additional chemical reactions can sometimes be beneficial, in which case the label ‘contaminant’ is replaced with reactant or catalyst. If the additional reactions are detrimental, other terms are often applied such as toxin, poison or pollutant depending on the chemistry involved. A major fraction of chemistry is involved with identifying, isolating, and studying contaminants.
"Contamination" also has more specific meanings in some sciences:
Contamination prevention in single-use systems: Colder's John Boehm discusses important considerations for biopharm manufacturing.(Single-Use Systems)(Interview)
Aug 01, 2008; Single-use systems are gaining greater acceptance in biopharmaceutical manufacturing as companies increase the diversity of...