| UF | Value | Justification |
|---|---|---|
| UFA | 3 | A UFA of 3 (100.5) is applied to account for uncertainty associated with extrapolating from animals to humans, using toxicokinetic cross-species dosimetric adjustment (HEC calculation) as specified in the U.S. EPA (1994) guidelines. |
| UFD | 10 | A UFD of 10 is applied to reflect the database limitations for the BaP analogue and the absence of repeat-dose and reproductive/developmental toxicity data for perylene. |
| UFH | 10 | A UFH of 10 is applied for interindividual variability to account for human-to-human variability in susceptibility in the absence of quantitative information to assess the toxicokinetics and toxicodynamics of perylene in humans. |
| UFL | 10 | A UFL of 10 is applied for LOAEL-to-NOAEL extrapolation because the POD is a LOAEL. |
| UFS | 1 | A UFS of 1 is applied because a developmental study was selected as the principal study. The developmental period is recognized as a susceptible life stage when exposure during a time window of development is more relevant to the induction of developmental effects than lifetime exposure (U.S. EPA, 1991). |
| UFC | 3,000 | Composite UF = UFA × UFH × UFD × UFL × UFS. |
BaP = benzo[a]pyrene; HEC = human equivalent concentration; LOAEL = lowest-observed-adverse-effect level; NOAEL = no-observed-adverse-effect level; POD = point of departure; p-RfC = provisional reference concentration; UF = uncertainty factor; UFA = interspecies uncertainty factor; UFC = composite uncertainty factor; UFD = database uncertainty factor; UFH = intraspecies uncertainty factor; UFL = LOAEL-to-NOAEL uncertainty factor; UFS = subchronic-to-chronic uncertainty factor.
From: APPENDIX A, SCREENING NONCANCER PROVISIONAL VALUES
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