Formaldehyde acts as a carbon donor between the diethyl-phosphorodithioic acid and tert-butylthiol groups in order to link them.

Terbufos, like other organophosphates, inactivates the acetylcholinesterase in humans by phosphorylation of the hydroxyl group of serine present at the active site of the enzyme.

A proposed metabolism pathway of terbufos suggests a hydrolysis of the thiolophosphorus bond, an enzymatic S-methylation, desulfuration and sulfoxidation occurred in succession.

Terbufos can enter the body through dermal absorption (skin contact), inhalation or ingestion of the compound.

The inhibiting effect of terbufos on AChE works on the peripheral muscarinic, nicotinic synapses and central nervous system.

[23][20] Symptoms of a terbufos induced ACC result in muscarinic (diaphoresis, vomiting, miosis, salivation), nicotinic (pallor and muscle weakness with respiratory failure) and CNS poisoning (headache, dizziness, altered level of consciousness) symptoms.

[24] The toxic effects can be managed by early recognition of terbufos poisoning, rapid decontamination and treatment with atropine or oxime compounds.

No developmental abnormalities were noted in research, but a reduced fetal body weight was observed in mammals.

[28] Though restricted for agricultural and not domestic usage in South Africa, terbufos and similar highly toxic substances are considered more effective than regulated options and can be found being sold by informal connivence stores, locally referred to as "spaza shops".

[28] As of January 2025, no link had been made between a specific shop and the deaths and the investigation had not determined whether the terbufos was locally produced or illegally imported.

Usually it is necessary to preserve the sample of the urine by addition of chloroform, to concentrate or extract the metabolites and to convert them to suitably-volatile derivatives.