Abolish a toxicant
Harvest a nutrient or medicine
Increase toxicant excretion: urine, feces, sweat, inhalation
Sustain a toxicant in body in a short time
Deposition in less susceptible organs (fat depots, skeleton)
Deposition in intracellular organelles
Formation of complexes (i.e. metallothionin and Se/Hg)