As the public's overall awareness of environmental stewardship and sustainable building practices have flourished, the insulation industry has responded by producing insulation products made from a variety of non-traditional materials; from food products to recycled clothing.
However, as these new "green" products are rushed to the marketplace in the hopes of being embraced by environmentally conscious consumers, it's important to take a broader look at what's green and what is not.
Many mistake new for green and believe that established products, like fiberglass, and rock and slag wool insulations, by virtue of having been around for awhile must not be green but this is simply untrue. Fiberglass and rock and slag wool insulation, also referred to as mineral wool, offer a wide spectrum of green benefits to both residential and commercial buildings. These benefits include the conservation of energy, resulting in improved air quality and pollution reduction; sustainable design attributes; and these products' naturally fire-resistant nature. The core purpose of insulation is to provide thermal efficiency, and to that end, all insulation is "green."
It's all greenA properly insulated home or building can significantly reduce the amount of energy used by effectively maintaining a desired temperature without the need to exert more energy. A well-insulated household can save approximately $780 per household for heating/cooling costs. 1These savings provide benefit not only to the customer but also to the environment.
Insulation is typically installed to code but code only represents the minimum required. Builders and homeowners interested in constructing a sustainable building should add insulation to the level needed to maximize energy savings, increase thermal comfort, provide acoustical control and protect the structure from moisture and air intrusion for the life of the building. Most often, the amount of insulation needed to produce all these benefits is above minimum code requirements.
Consider the following:
• Increased insulation lowers need for energy production, which reduces overall pollution emissions.
• Installed insulation prevents 1.56 trillion pounds/year of carbon dioxide from being emitted.2
• For every pound of carbon dioxide emitted in the production of insulation, 330 pounds of carbon dioxide emissions are avoided each year by the use of insulation.
• If the 46 million under-insulated existing single-family homes in the United States were insulated to the minimum requirements of the 2000 International Energy Conservation Code, the benefits would include 240 less premature deaths, 6,500 less asthma attacks and 110,000 less restricted activity days per year.3
With an understanding that all insulation is green, specifiers should assess insulation products on a variety of factors important to the project, including price, availability and those performance criteria and environmental attributes that will help meet the environmental and performance goals for the building in question.
Environmentally friendly insulationsThe key components of fiberglass are sand and recycled glass. Many in the building industry do not connect the spun fibrous glass used as insulation to the copious amounts of sand that occur naturally and perpetually. Based on EPA's definition, sand is a rapidly renewable resource,4one that will always be in plentiful supply because of nature's systematic and continuous disintegration of rock.
Geologists have estimated that the yearly production of quartz sand5 is in the order of 0.05 cubic kilometers per year: "Balancing new sand production against losses, led [geologists] to the conclusion that the total quantity of sand is increasing."6
Geologists estimated that during each and every second of the incredibly long past, the number of quartz grains on earth has increased by 1,000 million grains.7 Hence, the acquisition of sand as a raw material does not impose any impact on a non-renewable natural resource. As interest in green building and sustainable design continue to permeate the marketplace, it is important to understand the environmental attributes of such a widely used and beneficial product.
Slag wool is produced from blast furnace slag. Therefore, the acquisition of raw material does not deplete any natural resources. Additionally, the manufacturing of slag wool not only diverts materials from landfills but also uses materials mined from landfill sites further benefiting the environment.
Fiberglass, rock wool and slag wool insulation have been used in homes and buildings for more than 80 years. These are tried and tested products that provide thermal and acoustical benefits and help save energy. However, competitive marketing has helped to raise doubts about the environmental attributes of mineral wool, and this misinformation has penetrated the consumer and builder mindset. But for those interested in cost-effective green building, mineral wool products remain viable choices, and it is important to separate fact from fiction.
Fact: Mineral wool benefits sustainable construction. Fiberglass, and rock and slag wool insulations, are designed to last the life of the building. Batts and blankets can be removed and replaced during renovations and repair. Additionally, mineral wool loose-fill insulations do not settle over time.8 Other insulations must be over-installed in order to reach the stated R-value once they have settled.
The fiberization of glass, slag and rock allows it to be formed into a variety of shapes and sizes tailored to a specific need.9 This flexibility gives mineral wools the ability to spring back and retain full R-value after moderate compression. Therefore, fiberglass and rock and slag wool insulations will protect the structure throughout its lifecycle.
Fact: Fiberglass, rock wool and slag wool are naturally fire resistant. Fiberglass itself is inorganic and, as such, is noncombustible. Therefore, it does not require the addition of any hazardous fire retardant chemicals to be safely used in buildings. Many of the facings on fiberglass insulation are flammable and should not be left exposed in a building. Rock and slag wool insulations withstand very high heats and are typically used as passive fire resistance in buildings to protect occupants.
The fire test procedure currently specified for mineral wool insulation is ASTM E 84. The maximum flame spread allowable for mineral fiber is 25. All mineral fiber insulations manufactured by NAIMA member companies are within this limit.
A claim often heard in the insulation business is that certain types of insulation are fireproof because they are treated with chemical fire retardants. This is a tremendously misleading claim and it is expressly forbidden by the Federal Trade Commission. That, however, does not stop some manufacturers from using it in their marketing efforts. Insulations treated with fire retardants will burn and smolder, and have been shown to reignite after the initial fire is extinguished. The use of fire retardants does make these products non-combustible.
Fact: Mineral wool has been safely used in buildings for more than 80 years.
In the '80s, fiberglass insulation was labeled as a Group 2B (possible carcinogen) product by the International Agency for Research on Cancer. At the time, a limited amount of research existed on mineral wool insulation (which includes fiberglass, rock and slag wool).
Since that time, the industry has funded tens of millions of dollars in research through independent third parties to verify the safety of its products. In 2001, IARC changed the classification of mineral wool to a Group 3-not classifiable as to its carcinogenicity in humans.
In its decision, IARC emphasized, "Epidemiologic studies published during the 15 years since the previous IARC Monographs review of these fibres in 1988 provide no evidence of increased risks of lung cancer or of mesothelioma (cancer of the lining of the body cavities) from occupational exposures during manufacture of these materials, and inadequate evidence overall of any cancer risk."10
IARC's comprehensive review of the studies developed over the past 15 years indicates that some of the prior reviews now need to be updated. Many of these earlier reviews do not account for the new science. For example, the U.S. Department of Health and Human Services (HHS, Shalala, 1994) included fiberglass on its list of possible carcinogens based primarily on the 1988 IARC classification. Similarly, the California listing of fiberglass as "known to the state to cause cancer," was based primarily on the old IARC classification. Rock and slag wool have never been listed by NTP or the State of California.
During the time between the IARC reviews, competitive insulation products made full use of the classification to position fiberglass and rock and slag wools as bad products. However, no other type of insulation has conducted anywhere near the level of health and safety testing as the mineral fiber industry has done. When looking at choosing environmentally preferable products, specifiers and builders should demand to see proof of all health and safety claims. If health and safety information is not readily accessible, it should not be taken for granted.
Fact: Fiberglass, rock and slag wool requires more energy in production than some other insulations.
Embodied energy is an important attribute to consider when assessing the environmental impact of a product. Competitors routinely point to the amount of energy needed to produce fiberglass as a drawback of using the product. While production of mineral wool does require more energy than many other types of insulation, it is important to put this figure in perspective.
Studies show that it takes 10,444 Btus of energy to produce one pound of fiberglass insulation. This is equivalent to the output of a small window air-conditioner in one hour. That same pound of fiberglass insulation saves 125,328 Btus of energy per year. So, in its first year in a building, fiberglass insulation saves more than 12 times the amount of energy used in its production. Given that fiberglass insulation is designed to last the life of the building, the immediate and lifetime energy savings from this product offset the energy used in manufacturing the product.
Fact: Fiberglass contains at least 20 to 25 percent of recycled content; rock and slag wool contain 70 to 90 percent recycled slag. Fiberglass is made using sand and recycled glass cullet. It contains as much as 40 percent recycled content, and most products contain at least 20 to 25 percent. Because it takes more energy to melt recycled glass than it does sand, it would be counterproductive for fiberglass to use a significant amount of recycled content, because it would dramatically increase the energy used to produce the product.
Insulate greenIn the last 10 years, the fiberglass insulation industry has used more than 10 billion pounds of post-consumer glass saving in excess of 355 million cubic feet of landfill space. In fact, fiberglass insulation manufacturers recycle more material by weight than any other type of insulation used in the building and construction sector. According to the Glass Packaging Institute, fiberglass insulation is the second largest market for recycled glass containers.
Rock and slag wool typically contain 70 to 90 percent recycled blast furnace slag. In the past decade, rock and slag wool insulation manufacturers have diverted more than 11 billion pounds of slag from landfills.
Insulation in any form is beneficial to the environment. However, when choosing a "green" insulation, it is important to research the various benefits such as its ability to conserve energy, cost effectiveness, improved air quality and reduced pollution, an environmentally sustainable design and its fire-resistant nature.
Making an educated decision to go above and beyond face value of manufacturer claims will help to improve our current environment and allow the best insulation match for the job or project. All of these factors contribute to the "green" element of a product. The benefits of fiberglass insulation clearly demonstrate that fiberglass is a green product. W&C
Footnotes:1 Green and Clean Report, Alliance to Save Energy, April 2001 (Savings may vary. Find out why in seller's fact sheet on R-value. Higher R-values mean greater insulating power.)
2 Green and Clean Report, Alliance to Save Energy, April 2001
# Levy, Jonathan et. al., "The Public Health Benefits of Insulation Retrofits In Existing Housing in the United States," Environmental Health, 2003 2:4, http://www.ehjournal.net/content/2/1/4
3 60 Fed, Reg. At 50,733.
4 This is the type of sand generally used in the production of fiberglass insulation.
5 Pettijohn, Potter & Siever, Sand and Sandstone (New York: Springer-Verlag, 1973), p. 7.
7 Graves, R.S. and Yarborough, D.W., "An In Situ Evaluation of the Settling of Loose-Fill Rock Wool Insulation in the Attics of Two Manufactured Homes," Insulation Materials, Testing, and Application, ASTM, 1990, pp. 237-243.
8 Ellis, William S. "Glass, From the First Mirror to Fiber Optics, the Story of the Substance that Changed the World," Avon Books, 1998, pg. 7.
9 IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 81, Man-Made Vitreous Fibres
10 NAIMA Annual Member Recycling Survey