I have seen a lot of images and discussions on UFFI insulation which the toxic emissions I understand cannot be covered up but they do dissipate over time. It also appears that they should be removed if below a certain ppm (i believe it is 0.1 ppm). I started trying to educate myself on how long it takes typically for these levels to decrease to a point that they normally wont need to be removed and I didnt find that answer. 1) Do you have a resource on when this usually takes place. My logic is that this stuff has likely been in the attic for 30 years and it costs like $10K to remove so would nice to be educated on this one.
[FONT=Calibri]UREA FORMALDEHYDE FOAM INSULATION[/FONT]
February 4, 2014
[FONT=Calibri]By: Alan Carson Carson, Dunlop & Associates Ltd. and John Caverly, Building Inspection Consultants & Associates.
The purpose of this paper is to provide home owners and home buyers with the facts, and some guidance, concerning the use and safety of urea formaldehyde foam insulation (UFFI).[/FONT]
[FONT=Calibri]Urea formaldehyde foam insulation is injected as a mixture of urea formaldehyde resin, an acidic foaming agent, and a propellant, such as air. It was commonly used in existing houses by injecting the foam into areas, such as behind walls, where it was impractical to provide conventional insulation. The insulation was approved in Canada for use in exterior wood-frame walls only. It has a reasonably good R value (thermal resistance). Some formaldehyde gas is released during the on-site mixing and curing. Formaldehyde is colorless, but has a very strong odor, which can generally be detected at concentrations above one part per million. It is this by-product of the curing of the foam that became a controversial issue.
Formaldehyde is both a naturally occurring chemical, and an industrial chemical. It is found in dry cleaning chemicals, paper products, no-iron fabrics, diapers, pillow cases, the glue in particle board and plywood, cosmetics, paints, cigarette smoke, and the exhaust from automobiles, gas appliances, fireplaces, wood stoves. It occurs naturally in forests and is a necessary metabolite in our body cells.[/FONT]
[FONT=Calibri]Ambient formaldehyde levels in houses are typically .03 to .04 parts per million. By comparison, typical levels in the smoking section of a cafeteria are 0.16 ppm. Houses with new carpeting can also reach these levels.[/FONT]