Types
Reference doses are chemical-specific, i.e. the EPA determines a unique reference dose for every substance it evaluates. Often separate acute and chronic RfDs are determined for the same substance. Reference doses are specific to dietary exposure. When assessing inhalation exposure, EPA uses "reference concentrations" (RfCs), instead of RfDs. Note that RfDs apply only to non-cancer effects. When evaluating carcinogenic effects, the EPA uses the Q1* method.
Read more about this topic: Reference Dose
Famous quotes containing the word types:
“... there are two types of happiness and I have chosen that of the murderers. For I am happy. There was a time when I thought I had reached the limit of distress. Beyond that limit, there is a sterile and magnificent happiness.”
—Albert Camus (1913–1960)
“If there is nothing new on the earth, still the traveler always has a resource in the skies. They are constantly turning a new page to view. The wind sets the types on this blue ground, and the inquiring may always read a new truth there.”
—Henry David Thoreau (1817–1862)
“The American man is a very simple and cheap mechanism. The American woman I find a complicated and expensive one. Contrasts of feminine types are possible. I am not absolutely sure that there is more than one American man.”
—Henry Brooks Adams (1838–1918)