When a plant, an animal, soil, etc. is exposed to or treated with a crop protection product, the substances are taken up and metabolized (“digested”) by the biological system. Therefore, the residues of a product in a biological system might not come only from the substance itself but also from various other breakdown products known as metabolites.
Glyphosate has a unique combination of qualities that allows it to bind strongly to the soil, making it unlikely to be washed off into groundwater. It degrades into naturally occurring substances like carbon dioxide, nitrogen and phosphate.
To asses this degradation scientifically, metabolism studies are conducted.
- Giesy, J.P., Stuart. Dobson, and Keith .R. Solomon. 2000. Ecotoxicological risk assessment for Roundup herbicide. Reviews in Environmental Contamination and Toxicology. 167:35-120.