According to a recent insulation industry survey, the amount of pre- and post-consumer glass and blast furnace slag recycled over the past nine years has totaled more than 18 billion pounds.

Industry Touts Environmental Responsibility

According to a recent insulation industry survey, the amount of pre- and post-consumer glass and blast furnace slag recycled over the past nine years has totaled more than 18 billion pounds. The survey was conducted by the North American Insulation Manufacturers Association (NAIMA), which tracks the industry’s recycling efforts on an annual basis.


Since introducing its recycling program in 1992, the fiberglass insulation industry has recycled more than 8.4 billion pounds of glass. The use of recycled glass in the manufacture of fiberglass insulation continues to be the largest secondary use of pre- and post-consumer glass, and many fiberglass insulation products contain up to 40 percent recycled materials. In the year 2000 alone, more than 1.2 billion pounds of glass were diverted from the waste stream, saving 32 million cubic feet in landfill space.

Slag Wool

Slag wool is made from blast furnace slag, and therefore, does not deplete any natural resources. The industry’s manufacturers estimate that more than 90 percent of the slag used for insulation is new slag purchased directly from manufacturers. The remaining 10 percent is mined from waste disposal sites and landfills. Between 1992 and 2000, slag wool insulation manufacturers have recycled more than 9.7 billion pounds of blast furnace slag. The 1.2 billion pounds of slag diverted from the waste stream in 2000 would cover a football field to the height of 377 feet.

Spreading the News

“The benefits of using fiber glass and slag wool insulation to increase comfort and improve energy performance are well known,” notes Kenneth Mentzer, president and CEO of NAIMA. “But the fact that this industry is a leading recycler often is overlooked. The fiberglass and slag wool industries’ commitment to the use of recycled materials and its aggressive development of efficient production techniques that minimize waste water and other effluents demonstrates leadership in the environmental preservation arena.”

Fiberglass, Rock and Slag Wool Safety

Following a review of all available evidence by a scientific working group of the world’s leading experts on the health and safety of man-made vitreous fibers, the International Agency for Research on Cancer (IARC) has lowered the classification of international glass wool, rock wool and slag wool fibers from a Group 2B classification (“possibly carcinogenic to humans”) to a Group 3 classification (“not classifiable as to carcinogenicity to humans”).

IARC emphasized that “epidemiologic studies published during the 13 years since the previous IARC review of these fibers in 1988 provide no evidence of increased risks of lung cancer or 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.” 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 now are considered not classifiable as to carcinogenicity to humans.”

Much of the extensive medical-scientific research that was relied upon by IARC in reaching its decision was funded by the insulation industry in North America, and was conducted at leading independent laboratories and universities in the United States and abroad.

A complete report on the IARC panel’s findings is expected to be available later this year.

Acoustical Study Produces Sound Research

Insulation upgrade opportunities result from homebuyer education, according to results from a Johns Manville research study on sound control in the residential building industry. The study reveals that insulation contractors’ homebuilder customers could sell more sound insulation upgrades to homebuyers simply by educating consumers and offering the upgrades.

An independent research consulting firm — Kathy J. Speas and Associates — conducted quantitative research among consumers and builders to help determine to what extent sound control influenced home-buying decisions. After surveying consumers who had purchased homes built in 1998 or later, along with questioning homebuilders, research analyses show opportunities exist for homebuilders and insulation contractors to offer sound control upgrades to home buyers through simple education. That’s because one-third of homeowners questioned would have made different decisions about sound control in their new homes if they had been given more information.

“Our research demonstrates the residential consumer market for sound control is untapped, and contractors could create consumer interest and demand simply by offering sound control upgrades,” says Larry Gelin, research engineer in new products for Johns Manville. “Yet most builders don't offer sound control unless consumers ask for it. Building home-buyer awareness of sound control and sound control insulation creates opportunities to sell upgrades and for the consumer to have a quieter, more comfortable home.”

In fact, more than 80 percent of the builders surveyed agreed with the following two key statements:

If consumers ask for acoustical upgrades, the builder will add them to the homes.

If consumers were made more aware about sound control, there would be greater demand for materials that control sound.

All Demographics

Among the 17 percent of surveyed consumers who were offered sound control upgrades, a full 70 percent purchased those upgrades. Homeowners purchasing sound control upgrades were not markedly different from homeowners overall in demographics, nor were they restricted just to high-value homes. These commonalties among homebuyers provide builders of homes in all price ranges the ability to sell sound control upgrades.

According to the study, because 50 percent of consumers claimed never to have thought about sound control before, contractors have an incredible opportunity to not only educate homebuyers, but also to increase sound insulation upgrades to those home buyers.

“In contrast to home-buying decisions,” says Gelin, “many consumers automatically think of noise as the most important criteria when purchasing a major home appliance or an automobile.”

Common Annoyances

Sound control in the home needn’t be considered an inconsequential item. Eighty-five percent of homeowners surveyed are somewhat bothered by at least one of 17 common sounds included in the study. Additionally, nearly one-half are bothered very much by some sound in the home. Among the more annoying sounds: noise from appliances, water pipes and home theater systems. Other unwelcome sounds include those penetrating through walls or ceilings and floors.

Gelin explains, “Insulating for sound control is one new home upgrade that should be taken seriously by home buyers. Once drywall is installed, re-insulating interior walls becomes much more expensive and inconvenient. It is best to install sound control insulation before the interior walls are finished. That’s why we recommend doing it right the first time.”

Exposure Data Available

As part of the fiberglass, rock and slag wool insulation industry’s Health and Safety Partnership Program (HSPP), the North American Insulation Manufacturers Association (NAIMA) recently released a publication entitled “Exposure Data for Fiber Glass, Rock Wool & Slag Wool Under The Health and Safety Partnership Program.” The HSPP is a voluntary program for worker protection developed jointly by NAIMA, the U.S. Occupational Safety and Health Administration (OSHA) and key contractor organizations.

To help contractors and installers determine the level of potential exposure to fiberglass, rock wool or slag wool for a given task, an exposure database has been developed, containing information about exposure levels categorized by product type and specific work task. The exposure database is managed and maintained by Arizona State University.

In endorsing the HSPP, OSHA supports the ability of contractors to rely on this exposure database as the means for determining exposure levels. In the OSHA preamble to the Respiratory Protection Standard, OSHA states that “Data from industry-wide surveys by trade associations for use by their members, as well as from stewardship programs operated by manufacturers for their customers, often are useful in assisting employers, particularly small-business owners, to obtain information on employee exposures in their workplaces. It is clear that such programs often can assist employers to estimate workplace exposures reliably enough to make correct respirator choices without the need for employee monitoring.”

Exposure levels that exceed the Permissible Exposure Limit (PEL) for an eight-hour workday will require action to reduce the exposures to an acceptable level, either through engineering controls or respiratory protection. Information for the “Exposure Data for Fiber Glass, Rock Wool & Slag Wool” publication was taken from the database, which includes exposure data from a variety of sources, including manufacturers, contractors, academic institutions and third-party organizations.

To order copies of “Exposure Data for Fiber Glass, Rock Wool & Slag Wool Under the Health and Safety Partnership Program,” visit the NAIMA literature library at its Web site:

Midwest Conference

The Midwest Insulation Contractors Association’s 45th Annual Spring Conference takes place June 16-19 at the Tan-Tar-A Resort Golf Club & Spa in Lake of the Ozarks, Mo. The theme for this year’s conference is “Excellence in Insulation Through Education.” Hotel rooms are $125; call 800-826-8272 before May 20. For more information on the conference, call 402-342-3463.