View source for No observable adverse effect level (NOAEL)

'''NOAEL''' (No observable adverse effect level) denotes the level of [[exposure]] of an [[organism]], found by [[experiment]] or [[observation]], at which there is no biologically or statistically [[statistical significance|significant]] (e.g. alteration of [[morphology (biology)|morphology]], functional capacity, [[growth]], development or life span) increase in the frequency or severity of any adverse effects in the exposed population when compared to its appropriate control.<ref>[http://www.setonresourcecenter.com/cfr/40CFR/P132_003.htm Seton Resource Center]</ref><ref>[http://antron.dupont.com/content/resources/green_glossary/ant06_04_14.shtml]</ref>

In [[toxicology]] it is specifically the highest tested dose or concentration of a substance (i.e. a chemical) or agent (e.g. radiation), at which no such adverse effect is found in exposed test organisms where higher doses or concentrations resulted in an adverse effect.<ref>[http://www.fsra.net/glossary.html Food Safety and Risk Assessment] website at [[Glasgow Caledonian University]]</ref>

This level may be used in the process of establishing a [[dose-response]] relationship, a fundamental step in most [[risk assessment]] methodologies.

== References ==
{{reflist|2}}

== External links ==
{{medicine-stub}}

[[Category:Toxicology]]

[[de:NOAEL]]
[[it:NOAEL]]
{{WikiDoc Sources}}