Formaldehyde concentration


Indoors, where larger surface is covered with such materials, formaldehyde concentrations can reach much higher levels.
Measurements provided by our research group in buildings constructed from particle board and wood panels show that the levels of formaldehyde exceed in many cases the given standard. The concentration is, yet strengthened by equipment - furniture, carpets, textiles, etc.
The majority of formaldehyde measurements in the indoor environment was performed in primary and nursery schools and in boarding centers, where the use of risk wooden material is abundant. Measurements in the working environment and lodgings represent only a small portion of the whole.
The primary sources of measured indoor formaldehyde concentrations in the indoor environment were: wood panelling, the construction of the walls, supplementary thermal insulation, containing phenolformaldehyde adhesive, supplementary acoustic insulation implemented mostly at music schools. The results of indoor formaldehyde concentration short term measurements are presented in the table 1.

Table 1.Short-term indoor formaldehyde concentrations

Source
of HCHO Concentration range
[g.m-3] Average concentration [g.m-3]
wood panelling 0,0 - 167,5 32,5
thermal insulation 16,5 - 105,0 51,6
acoustic insulation 0,0 - 216,6 74,3

On the other side, the results of long-term measurements of indoor formaldehyde concentration are in the table 2.

Table 2: Long-term indoor formaldehyde concentrations

Source
of HCHO Concentration range [g.m-3] Average concentration [g.m-3]
wood panelling 3,0 - 40,8 10,4
thermal insulation 11,2 - 79,1 24,5
acoustic insulation 0,0 -147,9 45,9

Recent studies show that a lot of inhabitants are exposed to high levels of formaldehyde and other VOCs. It´s essential to know where they primary come from and try to avoid their usage in the indoor environment. Another way how to address indoor air pollutants would be to develop reasonable indoor air standards, all comprising technical, economic and legal questions. Still, more research is needed to find out how indoor air pollutants affect our health. Creative solutions of the engineers and designers can, in the large scale, reduce exposure to the potentially harmful substances.

Carbon Monoxide
The primary sources of carbon monoxide indoors are combustion gases from vehicles and tobacco smoke. Opened fires indoors can generate high contents. Carbon monoxide is also spread from garages. Normal, fresh outdoor air contains about 2 mg.m-3 of carbon monoxide. In busy streets the content is about 10 mg.m-3. Smoking in a room may increase the content by 5-10 mg.m-3.