UFFI is found adjacent to electrical outlets and switches and at the stud bays and wood plates of older balloon-framed houses. The foam is fragile and will break up easily.
The insulation was considered an ideal retro fit insulation with good insulation qualities. However, the material, once installed, would evolve off gas causing allergic reactions and respiratory problems in some people.
The material was banned in the United States in 1982 by the Consumer Product Safety Commission. In 1983, the ban in the United States was overturned by the U.S. Court of Appeals. The off-gassing of formaldehyde takes place over a 5 to 10 year period. The off-gassing period and its severity are affected by air relative humidity, the exposure to the sun and the ability for the humidity to access the walls. Since the material has not been installed since the early 1980s, the hazards associated with the off-gassing of the material are considered to be negligible.
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