Fiberglass insulation is made of plastic reinforced by tiny glass fibers. This gives the plastic additional strength and improves its insulation capacity. Fiberglass insulation may come in pre-made sheets or mats, or workers may spray the mixture into wall voids using a pressure hose. Protective gear is required when working with fiberglass because the tiny fibers and glass dust are a health hazard.
To create fiberglass, manufacturers use kilns to melt down silica and other materials and form the molten glass base. As this substance cools, it is fed through a system of rollers and tiny extruders to create extremely thin glass fibers. These are chopped into pieces and combined with plastic fill to create fiberglass insulation.
One of the primary problems with fiberglass insulation is its effect on humans. Touching fiberglass fill without protection can lead to contact dermatitis, as tiny particles break off and become lodged in skin pores. Breathing in fiberglass dust can lead to much more serious health issues because the particles can lacerate the trachea and lungs and may contribute to lung cancer. For this reason, workers applying fiberglass insulation are required to wear eye and skin protection and use a breathing filter to prevent inhalation of the material.