Renovation, every parent will take into account the harm of formaldehyde on the human body, especially for pregnant women and children, after moving in, many people will obviously smell the presence of indoor odor and will cause all kinds of discomfort to adults and children, so they will use a variety of ways to remove formaldehyde caused by the pungent odor. However, after a period of time, the unpleasant odor disappears, so parents forget to continue to take measures to remove the formaldehyde to ensure the safety of children and their own. Parents may not know is that the free formaldehyde in the air can persist for 10-15 years, smell the pungent odor when the formaldehyde exceeds the standard 4-8 times, even if you can’t smell it, the free formaldehyde in the air may still be more than the national standard of 3 times. Due to smell, neglected to prevent, wait until unknowingly poisoned when it is too late. And, formaldehyde is easy to volatile, summer, high temperature, windows and doors closed to open the air conditioning, air can not convection, harmful substances will be deposited, the greater the harm will be. Formaldehyde is colorless, with a strong odor of irritating gas, its 35% ~ 40% of the water solution commonly known as formalin. Formaldehyde is a protoplasmic poison, can be combined with proteins, inhalation of high concentrations of formaldehyde, there will be severe irritation of the respiratory tract and edema, eye stinging, headache, can also occur bronchial asthma. Direct skin contact with formaldehyde can cause dermatitis, discoloration, necrosis. Frequent inhalation of small amounts of formaldehyde can cause chronic poisoning, mucosal congestion, skin irritation, allergic dermatitis keratosis and fragility, nail bed finger tip pain, pregnant women long-term inhalation may lead to newborn babies deformities, or even death, men long-term inhalation can lead to men’s sperm deformities, death, decreased sexual function, severe leukemia, pneumothorax, lack of reproductive capacity, systemic symptoms of headache, fatigue, poor appetite, systemic symptoms include headache, fatigue, poor appetite, palpitations, insomnia, weight loss and vegetative nerve disorders. Various kinds of man-made boards (particle board, density board, fiberboard, plywood, etc.) can contain formaldehyde due to the use of urea-formaldehyde resin adhesives. Adhesives are used in the production of new furniture and in the decoration and laying of walls and floors. Where a large number of adhesives are used, there will always be formaldehyde release. In addition, some chemical fiber carpets, paints and coatings also contain a certain amount of formaldehyde. Formaldehyde can also come from cosmetics, detergents, insecticides, disinfectants, antiseptics, printing inks, paper, textile fibers and many other chemical and light industrial products.