Beyond Benign

Promoting Science Literacy

ask amy

“I am desperately trying to renovate a house using non-toxic products. I am very committed to using safer options. I have a huge challenge facing me as I try to figure out safe home insulation. Any ideas?” - S.A.

There are several different choices in home insulation materials. Home insulation has classically been done with fiberglass materials. Fiberglass offers many benefits: the material is made from sand and/or recycled glass; the fiberglass is naturally non-combustible and therefore no additional fire retardant is needed; and finally, fiberglass offers excellent thermal performance in insulating your home. The main drawback of fiberglass is the form of the material: fiberglass itself is essentially non-toxic to humans. However, the fiberglass is spun into a fiber form and when air born (due to installing or removing the insulation), fiberglass particles can be hazardous via inhalation. If the insulation is properly installed, then this exposure can be minimized by wearing proper respirators (a N 95 respirator approved by NIOSH).

Another material that is currently being marketed for insulating materials include recycled cellulosic materials such as denim and cotton fibers. Cellulosic manufacturers many times claim environmental benefit. However, many factors must be considered. Cellulosics (paper, cotton and denim) are many times removed from an existing recycling loop and therefore more trees are cut and more energy is used in making newsprint and cardboard to make up for what is not recycled. Also, cellulosics use 3 times more cellulose than fiberglass to achieve the same amount of insulating efficiency. The nature of cellulosic material is that it is combustible and therefore fire retardant materials are added; depending on the retardant that is used, this can pose an environmental and health hazard.

A third type of insulating material that is marketed for use in homes is blown or molded insulation. Blown insulation can come in many forms: fiberglass, cellulosic, and foam are the most common. The fiberglass and cellulosic materials pose the same risks as previously mentioned, but additional precautions must be taken upon applying the material since it is physically blown into the area and air born particles can be a hazard. Foam insulation can be advantageous due to the lack of particles; however, hazards can be found in the type of foam that is used. When researching insulating materials, look for “formaldehyde free” products. Many foams are polyurethane based. The polyurethane foams also many times contain low-conductivity gas such as HCFC’s, which pose some threat to the ozone layer. An alternative foam insulating material is that of cementitious foam insulating material. This spray-foam is made from minerals such as magnesium oxide, which are extracted from seawater, and offers a more environmentally friendly alternative to traditional foam insulation.

In all cases, be sure to read all warnings and take appropriate precautions before taking on the task of installing insulation. In the best case, insulation should be installed by professionals who are familiar with the materials being installed.

References and Links to More Information:

1. North American Insulation Manufacturers Association [http://www.naima.org]
2. A Consumer’s Guide to Energy Efficiency and Renewable Energy, U.S. Department of Energy, Energy Efficiency and Renewable Energy [http://www.eere.energy.gov/consumer/your_home/]