Organ system studies

NOAEL A No-Observed-Adverse-Eifect Level (NOAEL) is the highest exposure level at whieh no harmful effeets were seen in the organ system studied. Key number 18 reports a NOAEL of 3 ppm for the respiratory system whieh was used to derive an intermediate exposure, inhalation MRL of 0.005 ppm (see footnote "b"). 

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