o       Effective Dose – amount of substance required to produce a response on a given percentage of test subjects

o       ED₅₀ or effective dose-50% – the amount of substance that is required in order to cause the effect in 50% of the population of test subjects.

o       LD₅₀ or lethal dose-50% – the amount of substance needed in order to kill 50% of the test population.

o       Threshold Level – the dose that has no measurable response (1). The threshold level also determines the safe dose that can be absorbed without negative effects.