These are the same chemicals commonly found in day-to-day items such as beauty products, laundry soap and fertilizers. Glass fibre is comprised of sand, boron, phenol formaldehyde and a percentage of recycled glass product.
Cellulose is a loose-fill, fibrous insulation made from selected paper stock. Each bag displays Environment Canada's "Ecologo", classifying it as an "environmentally friendly" product. Cellulose may be hand poured or applied using a blowing machine. Machine application ensures that the cellulose is properly conditioned and placed at the required design density.
The great advantage of cellulose is that it forms itself to whatever cavity it is injected into. This enables it to fill the cavity with the most consistency and does not allow any voids.
Glass fibre batt is the most widely used type of insulation by contractors because it is cost-effective nature. It is also more environmentally friendly today, as major manufacturers are making formaldehyde-free fibreglass insulation.
Typically it is installed in formed batts for the walls and loose fill for the attic. If not installed properly the product can leave voids, which cause air gaps leading to increased heating/cooling costs. Loose fill product is made from the same material as batts but is left in its fibrous state and must be blown-in using a machine and delivery hose. Glass fibre is fire retardant by nature and will not rot or decay over time. The product is quick and easy to install but offers less thermal value than cellulose.
Cellulose and glass fibre function under very different principles. Cellulose is a paper product and derives its thermal value from the density of the product, which means less air movement. Glass fibre derives its thermal value from the air, which it traps within its fibres.