Propionic acid (PA) is widely used as an antifungal agent in food. It is present naturally at low levels in dairy products and occurs ubiquitously together with other short-chain fatty acids (SCFA) in the gastro-intestinal tract of humans and other mammals as an end-product of the microbial digestion of carbohydrates.

Formamide is a metabolite used for biological monitoring of workers exposed to N-N-dimethylformamide (DMF). There is a case of significant association between ever having been exposed to DMF and subsequent development of prostate cancer.

Deoxycorticosterone is a steroid metabolite produced by the adrenal gland. Deoxycorticosterone is an aldosterone precursor and possesses mineralocorticoid activity.