Other Considerations and Building Materials
Did You Know?
- Antimicrobials common in many building products contribute to antibiotic resistance in the very microbes they are designed to kill.
- Spray Foam Insulation, coveted for its energy-saving ability, contains isocyanates and amine, which are potent asthmagens, as well as toxic flame retardants and organotin catalysts.
- Polyvinyl chloride (PVC) is one of the most commonly used materials in building products in the world, and one of the most toxic to manufacture. It is in the same chemical family as DDT, and can take as long as 200 years to biodegrade.
- Wallboard often uses “recycled” fly ash from coal plants as a main ingredient, which contains toxic minerals and heavy metals such as asbestos, cadmium, lead, and mercury. When purchasing wallboard, use products with the lowest recycled content available.
Other Considerations and Building Materials
Antimicrobial chemicals have become common in building products. Most consumers believe they kill germs and viruses that cause illness. They are frequently found in carpets, concrete, countertops, door handles, light switches and covers, paints, tile, toilets and toilet seats, wall paper, and wood products. However, while antimicrobials are effective as biocide preservatives in products such as paint, there is no evidence antimicrobials are effective in creating better health. There is, rather, evidence that they can cause harm. (Perkins+Will, Understanding Antimicrobial Ingredients in Building Materials, March 2017. )
These chemicals are overtly toxic to people in sufficient doses, and even in small quantities can sometimes contribute to chemical sensitivity. When they leach from the material they are applied to through cleaning water, antimicrobials find their way to the wastewater supply and eventually the environment when treated sewage effluent is returned to waterways. This adversely affects aquatic life, and also people downstream who drink the treated water. Both triclosan and silver nanoparticles are appearing in increasing amounts in waterways and in human tissue samples, in part because they are commonly used in household products and building materials. Antimicrobials can also become airborne and harm indoor air quality.
Most worrisome is that antimicrobials are believed to contribute to antibiotic resistance in the very microbes they are designed to kill. Since these chemicals are not lethal to every single germ, germs that survive develop resistance and pass this trait on to their progeny.
Consumers should avoid these chemicals to the greatest extent possible by avoiding the purchase of building materials boasting antimicrobials as a selling point. People will pay dearly with cost premiums and environmental and health risks while getting no real added health benefits.
Though common insulation materials are not usually installed in the interior of a building, VOCs in them can offgas and adversely affect indoor air quality. Chemicals used in their manufacture can also harm workers exposed to them during installation.
Fiberglass and rockwool are mineral-based materials. Most residential fiberglass ceiling and wall insulation is relatively benign now that formaldehyde binders have been eliminated. There are some fiberglass-board duct liner products that are formaldehyde-free as well. Formaldehyde-free rockwool products are also entering the market.
Some people prefer cellulose and cotton insulation because they are renewable and biodegradable, However, both are treated with boric acid as a fire retardant. While less toxic than most other flame retardants on the market, in sufficient dosages, it is a developmental and reproductive toxin, endocrine disruptor, and organ toxicant.
Rigid-board or plastic-board insulation is typically used in new buildings as opposed to retrofit situations. Polyisocyanurate and polystyrene (expanded and extruded) are manufactured with fire retardants more toxic than boric acid. Expanded polystyrene also has pesticides in it to deter termites.
Spray foam insulation (SPF) combines an onsite two-part chemical combination of isocyanates and polyols with additives. It is the most hazardous of all insulation types. The implications of the chemical hazards contrast the material’s contribution to energy efficiency, since the use of SPF in wall cavities and under roof decks can turn homes into veritable thermoses that dramatically reduce heating and cooling needs.
But there is no getting around the chemical risks in SPF. Isocyanates and amine are potent asthmagens. Toxic flame retardants and organotin catalysts are also ingredients in spray foam. To add to these chemical concerns, a particular type of spray foam, “closed cell,” uses blowing agents manufactured with carbon tetrachloride, a fiendishly potent ozone depleting chemical.
There are SPF products that are third-party rated for their low-VOC and formaldehyde emissions. However, unexpected air emissions are more likely from this product class because the products are installed onsite and not factory controlled. (These installations may not all be made in accordance with specifications.)
Polyvinyl Chloride Plastic (PVC)
Of all common plastics, polyvinyl chloride, or PVC, is generally considered the most dangerous. It is in the same chemical family as the banned pesticide DDT, banned chemical PCBs, and dioxins, and is considered highly toxic to manufacture.
PVC manufacturing creates substantial amounts of dangerous air and water emissions, as well as hazardous waste. Chemical additives used in PVC products, such as phthalates that allow the material to be flexible, and organotin catalysts that render the material stable, are themselves toxic, and over time they can break down to harm indoor air quality or be absorbed through the skin.
In the event of fire, hydrogen chloride and heavy metals are released, and dioxins are created through the combustion process. In addition to these hazards, PVC takes as long as 200 years to biodegrade, and toxins in it bioaccumulate in the food chain.
For all these reasons, environmentally conscious consumers should avoid PVC products whenever possible. Yet they are ubiquitous in the average building. With the appropriate chemical engineering, this plastic can be made either rigid or flexible, and its versatility and relatively low cost has made it adaptable to many uses.
PVC building products include windows and doors, weatherstripping for windows and doors, blinds and shades for windows and (glass) doors, siding, plastic lumber for fences and decks, flooring, plumbing (particularly wastewater), shower curtains, wall paper, and electric-wire sheathing.
For the majority of these building products, non-PVC alternatives are available and relatively affordable, and should be chosen to make buildings as PVC-free as possible.
Gypsum wallboard is ubiquitous in buildings. Green building programs around the country have encouraged the use of pre-consumer recycled content in this product, which almost always means synthetic gypsum derived from the Flue-Gas Desulfurization (FGD) in coal power plants. Though it seems counterintuitive to say recycled content is not green, FGD gypsum contains toxic minerals and heavy metals such as asbestos, cadmium, lead, and mercury.
It is caustically ironic that mercury emissions around coal plants have fallen because of efficient pollution control devices while mercury emissions around drywall manufacturing plants have soared since 2000 because of widespread use of FGD gypsum.
These toxins can also be exposed to workers that install the product, and can, at least initially, get into house dust until installation clean-up occurs. The toxins can also leach into groundwater near landfills if dry wall scrap or old material is discarded there. Consumers that purchase new dry wall are encouraged to buy products with as little pre-consumer recycled content as possible.
Another variation of wallboard to avoid is products laminated with PVC film. These carry the same environmental problems as other materials made from PVC, with the added problem of low vapor permeability. Buildings need to breathe, and PVC coatings on walls lying on a building’s exterior or bordering a humid room may lead to condensation that can contribute to mold.
Environmental/Health Ratings for Insulation
A few agencies and institutions have created rating systems to certify insulation products.
This rating system administered by Underwriters Laboratories measures for VOCs emitted from many product categories, including insulation. It has two tiers: its standard GREENGUARD rating; and its premium GREENGUARD Gold rating.
Scientific Certification Systems, Inc. is a private company now operating as SCS Global Services. It certifies third-party verifications of environmental claims, including VOC emissions from insulation under its Indoor Advantage Gold program.
Safety Data Sheets (SDS)
These legally required summaries of potential product hazards are usually found on manufacturers’ Web sites. There are shortcomings for SDS information. Due to trade secrets, percentages of ingredients listed are often in vague ranges. SDS rules only require listing of hazardous ingredients if they make up more than 1% of a product, and carcinogenic ingredients if they make up more than 0.1% of the product.