Frigas E, Filley W V, Reed C E
Chest. 1981 Jun;79(6):706-7. doi: 10.1378/chest.79.6.706.
A patient developed severe asthma following insulation of her house with urea-formaldehyde foam. Bronchial challenge with the buoyant dust of the foam caused an asthmatic attack; inhalation of formaldehyde, 3 ppm, did not.