Advances in Safety Assessment Using "#34 Adjustment Factors. S. C. Lewis, Exxon Biomedical Sciences, Inc., East Millstone, NJ
Since 1954 (AJ Lehman, OG Fitzhugh, U.S.Q. Bull 18:33, 1954), safety assessment practices have relied on adjustment factors (a.k.a., uncertainty factors or safety factors) to account for inter-species variability and inter-individual variability (among humans). Over the first four decades of use, advances in safety assessment were marked by the introduction of additional adjustment factors. Factors were added to account for other sources of variability and/or uncertainty, such as the duration of the study (i.e., subchronic-to-chronic factor) or for data set quality/completeness ("factor". In 1990, Lewis, et al. first proposed the use of "#34 data-based adjustment factors (Reg Tox Pharm 11:314, 1990). A further-revised algorithm has been developed that readily incorporates advances in scientific understanding, reduces the number of judgments that are required to derive virtually safe exposure guidance, minimizes the influence of non-scientific considerations (i.e., social policy preferences), and provides guidance for planning follow-up research. A user-friendly guidance manual written for application of the method will be available.
Go to . . .
1999 SRA Table of Contents
1999 SRA Author Index
Main Abstracts Menu Page
RiskWorld Home Page