Exposure to MDI during the process of insulating buildings with sprayed polyurethane foam.

Buildings are often insulated with sprayed-in-place polyurethane foam in spite of the fact that few studies have been carried out on exposure levels to isocyanates during the spraying process. This paper is meant to provide new data on personal exposure to methylene-bis (4-phenylisocyanate) (MDI) while dwellings and office buildings are being insulated with polyurethane foam. An impinger using a 1-(2-methoxyphenyl)piperazine toluene solution as absorbent was used to take personal samples for the sprayer and helper during indoor and outdoor applications. The analytical results show that the levels of exposure were significant, especially for the sprayer, with values of up to 0.077 mg m-3 and 0.400 mg m-3 during outdoor and indoor applications, respectively. The helper's exposure was always lower.