Certain safety factor

The Certain Safety Factor is the ratio of the lethal dose to 1% of population to the effective dose to 99% of the population (LD1/ED99). This is a better safety index than the LD₅₀ for materials that have both desirable and undesirable effects, because it factors in the ends of the spectrum where doses may be necessary to produce a response in one person but can, at the same dose, be lethal in another.

<math>\mbox{Certain safety factor} = \frac{\mathrm{LD}_{1}}{\mathrm{ED}_{99}}</math>

See also

• Therapeutic index
• Effective dose
• IC₅₀
• LD₅₀
• EC₅₀

References

http://www.courses.vcu.edu/ptxed/m2/faqs_damaj.htm