1985

Liiri, Osmo; Kivistö, Antti; Kiviluoto, Jukka

The aim of the investigation was to clarity some factors influencing formaldehyde emission from particle boars used as wall lining and on the other hand, to confirm in practice the results of previous laboratory tests and of the tests discussed in the paper. The investigation concerning the treatment of the edges of particle board shaved that the edges always have to be preserved with paraffin wax before the chamber test in the laboratory. The same result is obtained when the edges are painted with reactive paint. When open joint is used in wall lining, or when the edges are otherwise left open, the edges must always be painted with a paint recommended for the surface of the board. When particle board is used in wall lining, it is not necessary to paint its back, or the surface towards the wall. The research results shaved that painting the face of the board in the recommended way is sufficient to prevent formaldehyde emission. The applied part of the research was carried out in a row house that was being built. Ten similar dwellings were used for the investigation. The test material consisted of standard particle boards, processed and special products, as well as of gypsum board as reference material. All partitions in one dwelling were always made of one type of board. The formaldehyde content of the air in the dwellings was measured during the different phases of the building process. Reactive paint was used for priming of standard boards, the prime of all other board types was latex paint. Latex paint was used as paint finish in all cases. The results show that after priming the formaldehyde content of the air was clearly lower than 0.15 mg/m3 in all dwellings. Thus particle boards painted according to the manufacturers instructions did not cause injurious formaldehyde contents. In the later phases of the building process and when the inhabitants had moved in, the formaldehyde content rose in all dwellings and in some of them as high as over the level of 0.15 mg/m3. This increase was partly due to other building and furnishing materials and to the habits of the inhabitants and, above all, to the very poor ventilation of the dwellings.