4. Elimination/excretion: how does our body get rid of chemicals?

4.1 Elimination routes

The physico-chemical properties of the substance and its metabolites determine the route of elimination.

• Urine: polar, water-soluble metabolites (benzene and phenol metabolites).

• Expired air: all volatile substances (solvents, ethylene, etc.).

• Faeces: lipophilic compounds excreted by labile (chlorinated aromatics, etc.) and inert products or undigested substances (kerosene oil, metals, etc.).

• Sweat and skin: certain metals (lead, mercury, arsenic, etc.).

The molecular weight of metabolites determines their excretion route.

• Low MW...