Health hazard: it has anesthetic effect on the central nervous system; It has a special selective effect on optic nerve and retina, causing pathological changes; Can cause metabolic acidosis. Acute poisoning: mild eye and upper respiratory tract irritation after short-term inhalation (gastrointestinal irritation after oral administration); After a period of incubation, headache, dizziness, fatigue, dizziness, drunkenness, confusion, delirium and even coma appear. Optic nerve and retinopathy may include blurred vision, diplopia and even blindness. When metabolic acidosis occurs, the binding force of carbon dioxide decreases and breathing accelerates.