(1) Organic solvents: such as paint, water-based coatings, adhesives, cosmetics, detergents, seam adhesives, etc;

(2) Building materials: such as wood-based panels, foam thermal insulation materials, plastic plates, etc;

(3) Interior decoration materials: such as wallpaper, other decorations, etc;

(4) Fiber materials: such as carpets, tapestries, and chemical fiber curtains;

(5) Office supplies: such as ink, copier, printer, etc;

(6) Improper design and use of ventilation systems, etc;

(7) Incomplete combustion of household fuels and tobacco leaves;

(8) Human excreta;

(9) Industrial exhaust gas, car exhaust, photochemical smoke, etc. from outdoors.

VOC is one of the common air pollutants in non industrial environments. More than 20 of them are carcinogens or mutagens. Due to their low concentration but diverse types, they are collectively referred to as VOCs, with TVOC representing their total amount (i.e. total volatile organic compounds). When the concentration of TVOC is too high, it is easy to cause acute poisoning. In mild cases, headache, dizziness, cough, nausea, and vomiting may occur; In severe cases, liver poisoning may occur, and even coma may occur quickly. Some may even be life-threatening. According to foreign medical research, pregnant women living in VOC environments have a much higher probability of causing fetal malformations than the general population, and may have an impact on their children's future intellectual development.