Formaldehyde mainly comes from interior decoration and decorative materials.Wooden wood-based panels such as plywood, joinery board, medium-density fiberboard and particle board are used for interior decoration. The adhesives used in the processing and production are urea-formaldehyde resin and phenolic resin. The main raw materials are formaldehyde, urea, phenol and other accessories. The remaining harmful substances such as formaldehyde that are not involved in the reaction in the sheet will gradually be released to the surrounding environment, forming the main body of formaldehyde in the indoor air, which causes pollution to the indoor air.Adhesives should be used for the decoration of new-style furniture, walls and floors.Formaldehyde will be released in all links where viscous agents are used extensively.In addition, wallpaper, chemical fiber carpets, plastic floor tiles, foams, coatings, paints and diluents also contain a certain amount of formaldehyde.

Formaldehyde is a colorless and irritating gas. The most sensitive to human health is smell and irritation, especially to the lining of the eyes, throat, and skin.When the formaldehyde content in the air is 011 mg/m3, there is an odor that makes people feel uncomfortable.

(The Indoor Air Quality Department of the U.S. Environmental Protection Agency believes that people will feel uncomfortable when they are exposed to formaldehyde for a long time indoors where the release reaches 011 ppm); reaching 015 mg/m3 can irritate the eyes and cause tears: 016 mg/m3 can cause throat discomfort or pain; as the concentration increases, it can also cause nausea, vomiting, coughing, chest tightness, and asthma; greater than 615mg/m3 can cause pneumonia, pulmonary edema and other injuries, and even lead to death.Long-term exposure to low-concentration formaldehyde (01017mg/m3～01068 mg/m3) can cause chronic respiratory diseases, menstrual disorders in women, pregnancy syndrome, decreased physique of newborns, chromosomal abnormalities, and even nasopharyngeal cancer.High concentrations of formaldehyde are toxic to the nervous system, immune system, liver, etc., and long-term exposure to higher concentrations of formaldehyde can cause acute mental depression.Formaldehyde also has pathogenic and carcinogenic effects.The International Institute for Cancer Research has recommended that it be classified as a suspected carcinogen.