Carpeting: tread carefully
Carpet systems, including carpet pads and adhesives, have been identified by the EPA as a potential source of indoor air pollution. Testing and monitoring are ongoing; the Green Label and more-stringent Green Label Plus programs of the Carpet and Rug Institute help prevent the most severe instances of toxic off-gassing from new carpet. High-end commercial carpets tend to be more chemically stable than inexpensive residential-quality carpets. Some manufacturers are willing to provide detailed air-quality testing data on their products.
Carpets may also contribute to air quality problems by trapping pollutants and moisture, and damp carpeting can provide a medium for growth of mold, mildew, and dust mites.
Flexible-foam carpet padding frequently contains brominated flame retardants (BFRs). These compounds, chemically similar to PCBs, are raising health concerns because they are being found in human blood and breast milk worldwide, and there is evidence of adverse health effects. BFRs from carpet padding can be released into the living space, especially as the carpet padding ages. In residences, hard flooring surfaces with area rugs, which can be thoroughly cleaned, are often preferable to wall-to-wall carpeting.
Modular carpet tiles can be replaced selectively, reducing the cost and environmental impact of recarpeting an entire room when one area becomes worn or damaged. Some carpet tiles also contain a high percentage of recycled content, and others can be resurfaced and reused. Carpet tiles with random patterns allow easy replacement of individual tiles. Some companies now have extensive recycling programs. When installing new carpeting, it may be possible to have the old carpeting hauled away for recycling at a price no higher than the cost of disposal.
Wood and bamboo flooring
Hardwood flooring from certified well-managed forests may be an excellent environmental choice. Other hardwoods come from forestry operations that may not be environmentally responsible. Due to the sensitivity of the ecosystems in which they grow, tropical hardwoods, in particular, should be avoided unless certified to Forest Stewardship Council standards, which involves third-party evaluation and monitoring of sustainable forestry practices.
Reclaimed and recycled wood flooring milled from the large timbers of old structures, trestle bridges, or “sinker logs” is another option.
Fast-growing bamboo is manufactured into hardwood-type strip flooring by a number of Southeast Asian companies, offering an intriguing alternative to standard hardwood. Very-low-formaldehyde products are now entering the marketplace, and at least one manufacturer claims to be formaldehyde-free.
Among the product choices:
- A wide variety of high-quality carpet is made from recycled soda bottles (polyethylene terephtalate, or PET) and offers the feel and performance of conventional carpet in residential or other low-traffic settings.
- Natural-fiber carpet with jute backing can be a good alternative to synthetic fibers, particularly if the carpeting is made domestically. Imported wool carpet is typically treated with pesticides before it can enter the country. Some sources suggest that the lifecycle cost of wool carpet, which includes the agricultural degradation of grazing and other factors, may be quite high.
- The underlayment used between a subfloor and floorcovering is often made from Lauan, a tropical hardwood that comes from unsustainable logging operations in Southeast Asia. Other underlayment products are available and should be chosen in consultation with your floorcovering supplier. For example, recycled-content, formaldehyde-free, gypsum-based underlayment is recommended by major tile manufacturers as a substrate. Under carpet, a recycled-newsprint-and-paraffin product is a good alternative. Wool underlayment is also available.
- Vinyl flooring, whose primary component is polyvinyl chloride (PVC), may be a source of VOC off-gassing, both from the flooring itself and from the adhesive. There’s also concern about toxic byproducts, such as dioxin, which may be produced in accidental fires or if the material is incinerated at the end of its useful life.
- Natural linoleum, made primarily from cork and linseed oil, is a possible substitute, though it’s currently manufactured only in Europe. VOCs are also released from linoleum—but these are from minimally processed linseed oil and are not generally considered as harmful as those from petrochemical sources. Nevertheless, some chemically sensitive people may find them problematic. Adhesives used for linoleum must also be screened carefully for toxic off-gassing.
- Ceramic and porcelain tile have a high embodied energy, but their durability makes them environmentally sound in the long run. Some high-quality ceramic tile incorporates recycled glass. Regionally produced stone flooring is a good natural finish when sealed with low-toxic sealers.
- Terrazzo is a long-lasting, nontoxic floorcovering option that uses crushed stone and, sometimes, post-consumer recycled glass in a cementitious matrix. The embodied energy of portland cement is a consideration. Epoxy-based “synthetic terrazzo” may also utilize recycled glass; while the 100-percent-solids product is considered safe for installers and is benign when cured, bispehonal-A (BPA) is used in the manufacture of epoxy. BPA is a bioaccumulating chemical considered by some experts to be an endocrine disrupter even at minute quantities. Like brominated flame retardants, BPA has been showing up in nature in increasing amounts.
BIBLIOGRAPHY ITEMS
Radiant Heating & Cooling Handbook
by Richard D. Watson et al.
(2002)
More bibliography items