Extruded polystyrene and polyisocyanurate foam insulation boards are currently made with CFC or HCFC blowing agents. Agricultural fiber insulation is available in the form of cotton insulation made with mill waste, low grade, and recycled cotton. It is treated with a non-toxic fire retardant and comes in batts comparable to fiberglass insulation batts. Cementitious foam insulation is made from magnesium from sea water and blown in place with air. Perlite insulation is made from a natural occurring volcanic mineral and is often used as loose fill insulation in concrete block cavities.
Insulation materials play a primary role in achieving high energy efficiencies in buildings.
There has been concern over the health impacts of the material constituents of insulation ever since the problems associated with asbestos became apparent, followed by the banning of urea formaldehyde based insulation. The health concerns have currently spread to fiberglass and cellulose insulation. Fiberglass is considered a risk by some because of the insulation fibers ability to become airborne and be inhaled similar to asbestos. Cellulose insulation uses recycled newsprint that contains printers inks which can possibly outgas formaldehyde into a home. If there is any outgassing from inks, it should fall well below levels irritating most persons.