Building insulation materials weak and brittle. Before its risks were recognized, it was used because it was a cheap, effective insulator with a high R-value and its open-cell structure was a good acoustic insulator. Though it absorbed moisture easily, it regained effectiveness as an insulator when dried. Asbestos once found common use as an insulation material in homes and buildings because it is fireproof, a good thermal and electrical insulator, and resistant to chemical attack and wear. It has been found that asbestos can cause cancer when in friable form (that is, when likely to release fibers into the air - when broken,
Cellulose insulation warming potential higher than that of carbon dioxide, cellulose does not produce significant gaseous emissions. Toxicity of the raw materials of insulation types is typically highest during manufacture or installation. Neither is a significant issue with cellulose. OSHA states that cellulose is a dust nuisance, requiring a dust mask during installation. The embodied energy of cellulose insulation is the lowest of the popular insulation types. It requires 20 to 40 times as much energy to produce furnace-made insulation materials compared to cellulose. Cellulose is made by electrically powered machines while mineral insulation is made in fuel powered furnaces, reducing this