How much formaldehyde is considered excessive? What is the state of formaldehyde under standard conditions?

Every corner of our lives may release formaldehyde, such as wall paint, furniture, etc. Especially for newly renovated houses and newly purchased furniture, the first three months are usually a period of intensive formaldehyde release. It is better to ventilate the house for a few months before moving in. Today we will learn some professional knowledge, such as how much formaldehyde is considered excessive and what is the state of formaldehyde under standard conditions. I hope it will be useful to you.

Contents of this article

1. How much formaldehyde is considered excessive

2. What is the state of formaldehyde under standard conditions?

3. Formaldehyde volatilization time and conditions

How much formaldehyde is considered excessive

If the formaldehyde content in the air is greater than 0.10 mg per cubic meter, it means that the formaldehyde content exceeds the standard. According to the relevant provisions of the indoor air quality standard, the indoor air formaldehyde limit is 0.10 mg/m³. On October 27, 2017, the World Health Organization's International Agency for Research on Cancer published a list of carcinogens, which listed formaldehyde as a Class I carcinogen.

Formaldehyde is an organic chemical substance, a colorless, irritating gas that is irritating to the human eyes, nose, etc.

Formaldehyde is easily soluble in water and ether, and the concentration of its aqueous solution can reach up to 55%. It can be miscible with organic solvents such as ethanol and acetone in any proportion, but is insoluble in petroleum ether.

Formaldehyde is very active in chemical properties. Under the catalysis of metals or metal oxides, it is easily reduced to methanol, and can generate formic acid or carbon dioxide and water when oxidized.

What is the state of formaldehyde under standard conditions?

Under standard conditions, formaldehyde has three states. The first is the free state. The second is the adsorption state of objects. The third is the combined state. It can be said that every corner of our lives may release formaldehyde, such as wall paint, furniture, etc.

First of all, try to choose solid wood furniture. The amount of formaldehyde released by solid wood is much lower than that of other woods, and is within the qualified formaldehyde emission standard range.

Secondly, choose a convenient formaldehyde removal method based on the characteristics of formaldehyde. Formaldehyde is soluble in water, so activated carbon can be used to help adsorb and remove formaldehyde.

Finally, based on the physical properties of formaldehyde release, ventilation is the best way to remove formaldehyde, that is, slowly releasing formaldehyde can effectively remove formaldehyde.

Formaldehyde volatilization time and conditions

The volatilization time of formaldehyde is generally about 3 to 15 years, and its conditions are mainly related to indoor temperature, relative humidity, air circulation and decoration materials. In general, the volatilization speed of formaldehyde is proportional to the temperature. Under high temperature and high humidity conditions, the volatilization speed of formaldehyde is relatively fast.

The boiling point of formaldehyde is 19°C. If the indoor temperature exceeds 19°C, the formaldehyde volatilization rate will increase by about 0.4 times for every 1°C increase. If it is in summer, when the climate is hot and the indoor temperature is high, the amount released will be relatively greater, and the concentration may even exceed 4 times the usual level.

Newly renovated houses and newly purchased furniture usually have an intensive formaldehyde release period in the first three months. During this period, formaldehyde will be released in large quantities, so it is recommended to keep the newly renovated house ventilated for more than three months before moving in. However, this does not mean that there will be no formaldehyde release after three months, but the amount and concentration are relatively small, and will change with changes in indoor temperature.