Inhalation of hydrogen sulfide can lead to acute poisoning and chronic injury. Acute hydrogen sulfide poisoning can be divided into three levels, mild poisoning, moderate poisoning and severe poisoning. The clinical manifestations of different degrees of poisoning are obviously different. Mild poisoning is manifested as photophobia, tears, stinging eyes, foreign body sensation, runny nose, burning sensation in throat, etc. Examination showed conjunctival congestion, lung dry rales and so on. In addition, symptoms such as mild dizziness, headache, fatigue, nausea, vomiting and ataxia may occur, and temporary disturbance of consciousness may occur. Severe poisoning shows obvious symptoms of the central nervous system, including dizziness, palpitation, dyspnea, slow movement, followed by irritability, unconsciousness, vomiting, diarrhea, abdominal pain, convulsions, etc., and soon died of respiratory paralysis. When exposed to extremely high concentration of hydrogen sulfide, "electric shock-like" poisoning may occur, and the contact person suddenly falls to the ground within a few seconds and stops breathing. Long-term repeated inhalation of a certain amount of hydrogen sulfide can cause olfactory decline, neurasthenia syndrome and autonomic nerve dysfunction.

Persons suffering from obvious respiratory diseases, organic diseases of nervous system, psychosis, severe neurosis and obvious cardiovascular diseases should not engage in hydrogen sulfide operations.

Before entering workplaces where hydrogen sulfide may exist, especially sewers, septic tanks, bottom holes, etc. Forced ventilation can be carried out first, and then small animals can be put in to observe whether there is poisoning, or the air in the field can be detected by direct reading tester or lead acetate test paper to confirm that the workplace is safe or free of hydrogen sulfide gas before entering the operation.