The use of safety factors for controlling risk.

Safety factors often are applied to animal bioassay data on toxic effects to establish dosage levels for which it is hoped there will be negligible deleterious effects on human health. A relationship between safety factors and disease risk is shown, making it possible to determine the size of the safety factor needed in order to maintain low levels of disease risk within animal populations. Also, it is demonstrated that "safe" doses obtained from the application of safety factors to the largest no-observable-effect level are similar to "safe" doses obtained by linear extrapolation.