Formaldehyde has many harmful effects on the body, especially on the respiratory and mucous membrane systems. 1. It can damage the eyelids and the mucous membranes of the respiratory and digestive systems, causing abnormal irritation and burning sensations in the eyes, nasal cavity and oral mucosa, making the eyes watery, dry and astringent. 2. 3, formaldehyde for the circulatory system, can lead to arrhythmia, insufficient blood supply and transient tachycardia, will appear chest tightness, shortness of breath, palpitations and other adverse phenomena. 4, finally, formaldehyde for the nervous system, can lead to neurological dysfunction, such as insomnia, dreamy, etc., but also dizziness, headache and other adverse phenomena, and even transient loss of consciousness.