It kills plants by inhibiting the enzyme glutamine synthetase, an enzyme also found in animals including humans. Glufosinate chemically resembles glutamine, a molecule used to transmit nerve impulses in the brain. Neurotoxic symptoms observed in laboratory animals following ingestion, dermal exposure or inhalation of glufosinate include convulsions, diarrhoea, aggressiveness, and disequilibrium.
Dogs appear to be the laboratory animal most sensitive to glufosinate.
Ingestion of glufosinate for two weeks caused heart and circulatory failure resulting in death. Exposure of pregnant laboratory animals to glufosinate caused an increase in premature delivery, miscarriages, the number of dead foetuses. Concentrations of a glufosinate-containing herbicide of less than than one part per million cause mortality of oyster and clam larvae. This metabolite is, like glufosinate, a neurotoxin. It is more persistent that glufosinate and has been found in wheat planted 120 days after soil treatment with a glufosinate-containing herbicide.