As we all know, furniture, especially new furniture, contains a large amount of formaldehyde, and formaldehyde does great harm to human body, which will affect the upper respiratory tract, stimulate eyes, even lead to leukemia, induce cancer, etc., which is the consensus of academic and medical circles. But at present, the research conclusion that can be confirmed is only qualitative research. How much indoor formaldehyde concentration can affect human health, that is, quantitative research has not formed a scientific conclusion.

四个因素有关：

Four factors are involved

1、室内温度。由于甲醛的沸点是19℃，当温度超过19℃后，室内温度每升高1℃，甲醛挥发速度就上升0.4倍，尤其是在夏季气温升高或冬季取暖时释放更加剧烈，浓度甚会超出平时的4倍。

1. Indoor temperature. Since the boiling point of formaldehyde is 19 ℃, when the temperature exceeds 19 ℃, the volatilization rate of formaldehyde increases by 0.4 times for every 1 ℃ increase of indoor temperature, especially when the temperature rises in summer or heating in winter, the concentration of formaldehyde will even exceed 4 times of normal.

2、室内相对湿度。湿度对甲醛的影响主要是因为家具板材内的脲醛胶是由尿素和甲醛聚合反应生产的，在湿度增大板材受潮情况下，脲醛胶遇水会分解成尿素和甲醛，从而加大板材内游离甲醛的含量，导致挥发空气中的含量也增加。

2. Indoor relative humidity. The influence of humidity on formaldehyde is mainly because the urea formaldehyde glue in furniture panel is produced by the polymerization reaction of urea and formaldehyde. When the humidity increases, the urea formaldehyde glue will decompose into urea and formaldehyde when the board is wet with water, which will increase the content of free formaldehyde in the board and lead to the increase of the content volatilized into the air.

3、室内空气流通量。由于室内甲醛的释放量是一个动态平衡，当室内的甲醛释放浓度达到一个平衡值时，室内的甲醛就不再释放了。当我们开窗换气，打破甲醛的这个平衡值，就会因为室内空气的流通量的变化，导致家具又会源源不断的释放甲醛，所以，通风是加速家具释放甲醛的方法。

3. Indoor air flow. Because the indoor formaldehyde emission is a dynamic balance, when the indoor formaldehyde emission concentration reaches an equilibrium value, the indoor formaldehyde will not be released. When we open the window for ventilation, breaking the balance value of formaldehyde, the furniture will continue to release formaldehyde due to the change of indoor air circulation. Therefore, ventilation is the best way to accelerate the release of formaldehyde from furniture.

4、室内装修材料的装载度。室内甲醛的释放源不是孤立存在的，根据释放源不同其挥发时间也不一样 ，墙壁涂料中的甲醛7-15天即可挥发的差不多了，壁纸胶中的甲醛18个月以上 ，大芯板中的甲醛 15个月5年不等 ，密度板贴面板中的甲醛几乎都在3年以上甚可超过10年。另外，由于各个甲醛释放源释放甲醛的速度相互影响和室内空间装修承载度的原因，所以，装修越复杂，甲醛挥发就越慢。

4. Loading degree of interior decoration materials. Indoor formaldehyde emission sources do not exist in isolation. According to different sources, their volatilization time is different. Formaldehyde in wall coating can volatilize almost in 7-15 days. Formaldehyde in wallpaper adhesive lasts for more than 18 months, and formaldehyde in large core board ranges from 15 months to 5 years. Formaldehyde in density board is almost over 3 years or even more than 10 years. In addition, the more complex the decoration, the slower the formaldehyde volatilization.

综上所述，新家具放置多长时间甲醛可以彻底释放完，这是一个伪命题，没有一个统一的标准答案。我们在挑选家具的时候，一定要挑选指数较高的板材家具，从源头上减少甲醛的含量。

To sum up, how long the new furniture can be completely released formaldehyde is a pseudo proposition, there is no unified standard answer. When we choose furniture, we must choose the board furniture with higher environmental protection index to reduce the formaldehyde content from the source.