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Preferred Term:

no observed adverse effect level

The highest exposure level at which there are no biologically significant increases in the frequency or severity of adverse effect between the exposed population and its appropriate control; some effects may be produced at this level, but they are not considered adverse or precursors of adverse effects.
Concept Schemes:
Broader Concept:
Entry Terms:
  • no-observed-effect level
  • no observed effect level
  • NOAEL (no observed adverse effect level)
  • no-observed-adverse-effect level
  • NOEL (no observed effect level)
  • no observable effect concentration
  • NOEC (no observed adverse effect level)
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RDF/XMLCreated 2006-01-19, last modified 2017-10-11