Extending the threshold of regulation concept: de minimis limits for carcinogens and mutagens.

Risk assessment processes for carcinogens are highly developed but risk assessment processes for mutagens are not well established. In the pharmaceutical industry, risk associated with exposure to carcinogens is tightly controlled. It is desirable to control risk associated with exposure to mutagens also, in spite of the greater uncertainty associated with the risk. In this paper, a published cancer potency database is used to frame the risk and to support risk management decisions. A de minimis exposure for mutagens is proposed and a decision matrix is presented to align available data with risk assessment approaches for carcinogens and mutagens.