Formaldehyde is a volatile toxic gas, and poisoning is divided into acute and chronic poisoning. In acute poisoning, the gas irritates the eyes and respiratory tract, resulting in dry, painful, tearing eyes, irritating dry pain in the nose and throat, and an irritating cough. If laryngeal edema or pulmonary edema is caused, respiratory distress can also occur, which can lead to asphyxiation and death in severe cases. In addition, neurological symptoms can occur, with dizziness, nausea, and vomiting. If more serious, there will be coma, convulsions, and even central respiratory and cardiac depression leading to respiratory and cardiac arrest and death. Chronic formaldehyde poisoning can be manifested as symptoms of neurasthenia, such as memory loss, frequent insomnia and dreaming or uncoordinated hands and feet, dizziness and other symptoms, and in severe cases, the hematopoietic system will be affected, resulting in anemia, and even more serious cases will lead to leukemia.