Editing Reagent (section)

==Commercial or laboratory preparations==
In commercial or laboratory preparations, {{anchor|Reagent_grade}}'''[[chemical purity|reagent-grade]]''' designates [[chemical substance]]s meeting [[standardization|standards]] of [[purity (gas)|purity]] that ensure the scientific precision and reliability of [[chemical analysis]], chemical reactions or physical testing. Purity standards for reagents are set by organizations such as [[ASTM International]] or the [[American Chemical Society]]. For instance, reagent-quality water must have very low levels of impurities such as [[sodium]] and [[chloride]] ions, [[silica]], and bacteria, as well as a very high [[electrical resistivity]].  Laboratory products which are ''less'' pure, but still useful and economical for undemanding work, may be designated as ''technical'', ''practical'', or ''crude'' grade to distinguish them from reagent versions.