" . . . cold and heat . . . summer and winter . . . shall not cease."

– Genesis 8:22

"Warmth, warmth, more warmth! for we are dying of cold and not of darkness."

– Miguel de Unamuno

The Tragic Sense of Life

The North American Insulation Manufacturers Association (NAIMA) and its member companies have promoted, with steadfast confidence, the usefulness and safety of its insulation products since the 1930s. The industry’s faith in its fiber glass and rock and slag wool ("man-made vitreous fibers" or "MMVFs") insulation products has never wavered. Even in 1987, when the International Agency for Research on Cancer (IARC) identified MMVFs as a "possible human carcinogen," the industry retained its same message of assurance: "Fiber glass, rock wool, and slag wool products are safe to manufacture, install, and use when recommended work practices are followed."

That 1987 IARC opinion on a cancer risk associated with MMVFs is now history.

On Oct. 16, 2001, after reviewing all available studies and publications addressing man-made vitreous fibers, a panel of leading, international medical and scientific experts appointed by IARC concluded their health and safety evaluation of these fibers by re-classifying MMVFs from a Group 2B category ("possibly carcinogenic to humans") to a Group 3 category ("not classifiable as to carcinogenicity to humans").

IARC based its decision upon the evidence of "Epidemiologic studies published during the 13 years since the previous IARC Monographs review of these fibers 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 [emphasis added]." Other fibers reviewed in 1988 retained their original classification. IARC further stated that "…the more commonly used vitreous fiber wools including insulation glass wool, rock (stone) wool and slag wool are now considered not classifiable as to carcinogenicity to humans (Group 3)."

IARC’s decision marks a historic victory for the industry because it affirms what NAIMA and its members have been saying for years and continue to say today.

A Firm Foundation Supported Industry Confidence

While NAIMA enthusiastically applauds IARC’s reclassification of MMVFs, the agency’s action is no surprise in that it’s in sync with conclusions reached by scientific groups in the United States, United Kingdom, Canada, Holland, Australia, and New Zealand that concluded, in the past five years, that MMVFs don’t pose a cancer risk to humans. For instance, the U.S. National Academy of Sciences found in 2000 "no significant association between fiber exposure and lung cancer or nonmalignant respiratory disease in the MVF manufacturing environment."

The abundant information relied upon by these reviews appeared in print as early as 1930, when research on man-made vitreous fibers found an absence of any chronic adverse health effects in man. By 1942, initial investigations conducted by Dr. W.J. Siebert on fibrous glass manufacturing workers demonstrated "no respiratory disease could be attributed to inhalation of fibrous glass." Studies from the 1950s and 1960s corroborated the findings of earlier research efforts. In 1977, the Consumer Product Safety Commission (CPSC) conducted an extensive investigation into the health and safety of fibrous glass home insulation and concluded that scientific evidence did not support a finding that inhalation of fibrous glass home insulation posed "an unreasonable risk of injury from cancer," and, therefore, the commission declined to regulate fiber glass and found that "a mandatory safety standard was unnecessary."

MMVF insulation products rank as one of the most thoroughly tested building materials in use today. More than 60 years of research by government and independent research organizations supported the statements made by industry that MMVFs are safe when manufactured, installed and used following recommended work practices. This ongoing product stewardship sustained the industry’s confidence in its products and established that workplace exposure to respirable fibers consistently registers below 1 f/cc and airborne fibers in insulated buildings are not significantly different from the level found in the outdoors or in uninsulated buildings.

With this substantial scientific database as a backdrop, in 1999 NAIMA partnered with the U.S. Occupational Safety and Health Administration (OSHA) to form a voluntary Health and Safety Partnership Program. As a result of this partnership program, OSHA removed MMVFs from its list of priorities.

Health Benefits of MMVF Insulation Products

Medical professionals identify a home as a critical element in gaining and persevering good health: "A house should protect its occupants from extremes of heat and cold, moisture and dryness" and maintain "a comparatively constant interior temperature."

Such an indoor climate, doctors reminded patients, was attainable due to the "development of a lighter wall with some good insulating material in it." Modern insulation proved so fundamental to good health that the Modern Medical Counselor in 1945 urged readers to follow this advice: "If modern insulating materials are used in the building of a new home, it will be better protected against the extremes of heat and cold and will conserve fuel." Dr. Hubert Swarthout’s book even featured a photograph of MMVF insulation being installed. Insulation, Swarthout advised, also reduced vermin, insects, and germs. The health benefits derived from a controlled indoor climate provided yet another rationale for NAIMA’s unwavering confidence in MMVF products.

Surviving Weather and Climate

Plagues once brought a blight upon humanity, but even Black Death itself stopped when even slight improvements in housing generated "spectacular results" to human health, argues William McNeill, professor emeritus of history at the University of Chicago. Housing, due to its insulating concepts, helped to end epidemic contagions: "Invention of clothing and housing did the trick, insulating the human body from extremes of climate and assuring survival despite freezing temperatures." Weather injures normal and diseased people more, according to cardiology studies, "than all air and water pollution combined." Indeed, cold ranks as the gravest threat to the body.

In her fascinating book, "Freezing Point," Lucy Kavaler explains that "man has not evolved in ways that help him to endure the cold. . . he has been battling cold as if it were an enemy for all history."

Cold kills people even today. Heat kills people, too. Technology eventually achieved stabilized temperature control with the development of efficient insulation, which, according to historian James Burke, came with the breakthrough discovery of glass fiberization, that led, ultimately, to the creation of "glass wool, an extremely light-weight insulation blanket." As history and literature document, insulation played a pivotal role in bestowing comfort and well-being upon the human race.

Cold Kills

In 1860, a Washington, D.C. woman wrote: "I can no more stand cold weather than can a tomato plant." Indeed, "[m]an as a species has not developed a race that can naturally survives in cold regions. Only technology has enabled him to do so." Technology prevents heat loss by providing insulation [like] "[f]eathers and furs . . . match the processes that would . . . carry heat away from the body. In houses man has done the same thing by walls, fiber insulation, and storm windows."

In Dr. Stephen Rosen’s, "Weathering," he explains how the body "rel[ies] upon unconscious behavioral thermoregulation – . . . But body temperatures above 110 [degrees fahrenheit] or below 82 [degrees fahrenheit] for extended periods of time can inactivate thermoregulation and prove fatal."

A striking illustration of Rosen’s statement, occurred in the early 1960s in Great Britain when fatalities among elderly and infants rose sharply enough for the British Ministry of Health to appoint a special committee to investigate. In its 1964 report, published in the British Medical Journal, the committee’s findings attributed all deaths to accidental hypothermia. Accidental hypothermia differs from the hypothermia caused when a victim is stranded in Antarctica. In contrast, accidental hypothermia claims its victims within the walls of their own homes. The age of the victims also contributes to accidental hypothermia, because "old people are… vulnerable to cold… and many… lay unprotected for long periods in cold rooms."

Infants suffer similar susceptibility, as a 1932 report from President Hoover’s Commission on Home Buildings stated: "We recommend particularly that investigations be made upon the relation of housing to infant mortality . . ." In short, dwellings occupied by the victims lacked capacity for sustained temperatures needed to maintain proper body warmth. Without equivocation, the committee blamed indoor exposure to cold as cause of death.

The Ministry of Health’s recommendations centered on implementation of measures that would correct loss of heat from a room. To achieve temperature stability, the committee recommended that flats and apartments install insulation in attic spaces to attain a persistent room temperature. In a follow-up article, "Cold the Killer," to the committee’s official report, British Medical Journal editors characterized cold’s deadly toll as a "medical emergency" and demanded social and governmental intervention: "The old people should be given help, with insulation of their houses and provisions of warm clothing and fuel, by official or voluntary services and should themselves be warned of the danger."

Before modern innovations in home construction, the cold threatened everyone, not just the aged and new-born, as illustrated in Willa Cather’s classic American novel, "My Antonia," with its depiction of pioneers fighting nature’s brute force in Nebraska, where "man’s strongest antagonist is cold." Not complaining, just stating the facts, one pioneer remarked that "[n]ext to getting warm and keeping warm, dinner and supper were the most interesting things we had to think about. Our lives centered around warmth and food." Securing warmth remained elusive for many as exemplified by a farm house where wintry winds whipped beneath door seams and through wall crevices, and burlap bags stuffed between the cracks and crannies to stop glacial-like air proved fruitless as temperature dropped to deadly degrees.

Heat Kills

Hot climates present mankind with hazards almost as lethal as cold. Indeed, torrid temperatures prove fatal to mankind with regularity as even today heatstroke stalks the inhabitants of the upper half of the Mississippi River region, where more lives have been taken by heat-related injuries than in any other location in the world. While medical dissertations reveal that "heat is much more difficult at the two extremes of life, making the elderly and babies most susceptible to heat," American soldiers fighting overseas during World War I and World War II succumbed to the heat with regularity.

After both world wars, the Medical Department of the U.S. Army prepared an extensive evaluation of all heat-induced medical problems-hospitalized illnesses and death-in an effort to prevent such devastating losses if future American military conflicts arise in tropical climates. In the report, the Army recognized that a shelter, where cool temperatures might abound, could have circumvented both sickness and death affiliated with over-exposure to heat during both World Wars. Once again, insulation protects against climate’s extremities.

Energy Efficiency Equals Better Health

Energy-efficiency technologies contribute towards reducing pollution-sulfur dioxide and carbon dioxide. Carbon dioxide contributes to global warming and sulfur dioxide constitutes a major component of acid rain, so insulation possesses the capacity to diminish the threat of climate change and reduce health risks linked with acid rain.

In addition, air pollutants provoke allergic symptoms, and exacerbate respiratory distress among asthma sufferers. Asthma is on the increase among people who live in urban areas because of the intensified levels of airborne pollutants and allergens. Air pollution has also been linked to emphysema, hay fever, other respiratory ailments, headaches, constricted breathing passages, or health hazards that remain hidden from medical knowledge. Scientists suggest exposure to pollutants can worsen existing health conditions, and, combined with all other factors, accelerate disease and allow air toxins, like arsenic, to accumulate in the body and contaminate the blood stream.

Insulation use decreases the emission of pollutants with dramatic results. Insulation currently in place in U.S. buildings alone reduces the amount of carbon dioxide emissions by 780 million tons each year. A savvy environmentalist, Paul Hawken, stated that "ceiling insulation and double glazed windows can produce more oil than the Arctic National Wildlife Refuge at its most optimistic projections, at about one-twentieth the cost, with four times the employment per unit of energy converted versus the energy consumed by burning it."

In a study conducted by the Alliance to Save Energy, Hawken’s optimism gains authentication: "10,444 Btu’s of energy are required to produce one pound of insulation. One pound of insulation saves 125,3289 Btu’s of energy per year." Hawken’s "The Ecology of Commerce" justified heavy reliance upon energy efficiency because present efforts have eliminated "hundreds of billions of tons of pollution from the air, ground, and water, and improved health world wide."

MMVF insulation products earn the lion’s share of credit for energy savings and pollution reduction, because, as A.M. Watkins states in "The New Complete Book of Home Remodeling, Improvement, and Repair," of the many types of insulation, fiber glass and mineral wool are the most common. And "the most recommended." Watkins justifies his praise by listing distinctive attributes embodied in fiber glass and mineral wool: "high performance rating . . . inorganic . . . naturally fire resistant, rot proof, bug resistant, versatile, and not high priced."

Insulation Noise Absorption Offers Health Benefit

Scientists have linked "sensations of sound" to negative impacts on human health. When President Hoover’s Conference on Home Building and Home Ownership published its report, experts pinpointed noise as a injurious presence that needed resolution: "Noise has a detrimental effect upon health, and houses should be so constructed as to minimize" the noise. Indeed, psychological and physiological ailments results from noise that disturbs peace and quiet and prevents restful slumber or loss of sleep and inflicts stress related diseases upon its victim. Medical sources support the conclusion that sustained exposure to noise is contributing factor in impaired hearing chronic fatigue, neurasthenia, increase blood pressure and decreased working and mental efficiency.

That explains why acoustical expert Paul Close stated that there "is ample justification for classifying noise as an occupational hazard along with gases, fumes, dust, toxic liquids, and bacteria."

MMVF insulation absorbs noises that cause detrimental health effects. In fact, specialists in acoustical problems recommend insulation as an effective tool for reduction of sound through walls, floors and ceilings and absorption of reverberations. The result is improved health, yet another insulation health benefit resulting in NAIMA’s confidence.

Final Thoughts

Insulation transformed standards of comfort and living for all classes, and has ushered a comfort and well-being that historians call "a tremendous advance" for humanity. Health and happiness are closely related, and it would be difficult to deny that a more varied diet, better protection against cold and damp (indoors and out) and cleanliness have been facilitated by modern technology and are directly responsible for happiness as well as health.

Certainly, the impact of technology is clearly apparent in the realm of architecture, structures made to control the natural world for the benefit and, ultimately, for the survival of humanity.

MMVF insulation products, the preferred insulation choice for decades, have not only been extensively used, but have been extensively studied, researched, and scrutinized. Now, supported by IARC’s significant landmark decision, NAIMA and its members reassert its consistent message once again:

"Fiber glass, rock wool, and slag wool products are safe to manufacture, install, and use when recommended work practices are followed."