Formaldehyde itself has strong chemical activity, and its half-life in the environment is generally within a few hours. Generally, it will not have a high concentration outdoors and is not a major pollutant.

However, for health, since most people spend most of their time indoors, there are many sources of formaldehyde release indoors, and the indoor concentration is generally higher than outdoor. If it cannot be handled in time, it may cause greater harm. 

The porous structure of activated carbon provides a large amount of surface area, which makes it easy to achieve the purpose of absorbing impurities such as formaldehyde. A large number of molecules on the activated carbon can generate a large gravitational force, so as to achieve the purpose of attracting harmful gases in the air into the pores. Using this principle, we can filter harmful substances such as formaldehyde and benzene in the air. The more pores of activated carbon, the higher the adsorption performance. It is recommended to choose activated carbon with low density, light hand feel, and large volume of equal weight. In addition, the smaller the activated carbon particles, the larger the contact area with air, the larger the specific surface area, and the better the adsorption performance.