From
ATSDR:
An
MRL is an estimate of the daily human exposure to a hazardous
substance that is likely to be without appreciable risk of adverse
noncancer health effects over a specified duration of exposure.
These substance-specific estimates, which are intended to serve
as screening levels, are used by ATSDR health assessors and other
responders to identify contaminants and potential health effects
that may be of concern at hazardous waste sites. It is important
to note that MRLs are not intended to define clean-up or action
levels for ATSDR or other Agencies.
