An estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population that is likely to be without risk of deleterious effects during a lifetime. It can be derived from a no-observed- adverse-effect-level (NOAEL), lowest-observed-adverse-effect-level (LOAEL), or benchmark concentration, with uncertainty factors generally applied to reflect limitations of the data used. Reference concentrations are generally used in the U.S. Environmental Protection Agency's noncancer health assessments and expressed in milligrams per cubic meter (mg/m3).
A concentration specified by EPA to limit human inhalation exposure to potentially hazardous levels of chemicals in air.
An estimate of the daily inhalation dose, expressed in terms of an ambient concentration, that can be taken daily over a lifetime without appreciable risk. more
EPA's estimate for the human population, including sensitive subpopulations, of the daily exposure by the inhalation route likely to be without appreciable risk of harmful noncancerous effects during a lifetime.
A concentration in air expected to be associated with no deleterious health effects over a lifetime of exposure, assuming default body weights and inhalation rates.
(RfC) - An estimate (with uncertainty spanning about an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of harmful effects during a lifetime. It can be derived from various types of human or animal data, with uncertainty factors generally applied to reflect limitations of the data used.
An estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime. It can be derived from a NOAEL, LOAEL, or benchmark concentration, with uncertainty factors generally applied to reflect limitations of the data used. Generally used in EPA's noncancer health assessments. [Durations include acute, short-term, subchronic, and chronic and are defined individually in this glossary].
An estimate of a continuous inhalation exposure for a given duration to the human population (including susceptible subgroups) that is likely to be without an appreciable risk of adverse health effects over a lifetime. It is derived from a BMCL, a NOAEL, a LOAEL, or another suitable point of departure, with uncertainty/variability factors applied to reflect limitations of the data used. [Durations include acute, short-term, subchronic, and chronic and are defined individually in this glossary]. This definition archived 12/23/05