Formaldehyde and urea formaldehyde cavity wall insulation

Formaldehyde and UF foam cavity wall insulation Urea formaldehyde (UF) foam cavity wall insulation was introduced into this country, from Denmark, in 1959. Relatively little was installed until after the oil crisis which followed the Arab‐Israeli War of 1973. In total, some 1.5 million buildings have been insulated with it. UF foam is the cheapest material for retrofit cavity wall insulation. (All well‐installed systems have a comparable heat resistance.)