Formaldehyde poisoning is usually divided into acute poisoning and chronic poisoning. If it is acute poisoning, it is usually caused by inhaling too much formaldehyde gas at once in a space with a high concentration of formaldehyde gas. The symptoms of acute poisoning, such as nausea, vomiting, dizziness and headache, can usually appear within 10 minutes. Severe patients can experience irritating cough, breathing difficulties, coma, convulsions, shock and even life-threatening manifestations. In case of chronic poisoning, it is usually caused by long-term work and living in an environment where formaldehyde concentration is not high. Usually 2-3 months can gradually cause poisoning, which can lead to lesions in the hematopoietic system or bone marrow system and thus produce serious sequelae.