The No-Fly-Ash Zone: Alternative Recycled Materials in Carpet Backing

Sarah Gilberg | July 08, 2011 | Materials

A few weeks ago on the Signal blog, we examined some of the tradeoffs in choosing a carpet for its recycled content, particularly with regard to carpet backings made with coal fly ash, a coal combustion waste product which has been found to contain mercury and other hazardous heavy metals.  Pharos allows subscribers to evaluate not only complete carpet styles but also individual carpet components (fibers and backings), because we find a lot of innovation and differentiation at the component level.  Our research on carpet products and their components for the Pharos Building Product Library has led us to some interesting alternatives, including carpet backings that achieve high scores for recycled content without fly ash.

Tandus Flooring, for example, uses post-consumer recycled polyvinyl butyral (PVB) in ethos™ backings used in Powerbond resilient sheet flooring and modular carpet styles.

When we asked Tandus why they chose to develop this alternative, they attributed the choice largely to demand from a major customer.  Ross Leonard, Director of Marketing for Tandus Flooring, explained, "About ten years ago, Tandus Flooring was asked by Kaiser Permanente to collaborate with them in the development of a new type of floorcovering for their facilities.  Among the key criteria for this new floorcovering was that it had to made without chlorinated polymers, had to contain high levels of post-consumer recycled content that could be third-party certified, be fully recyclable using currently existing technology and processes and meet Kaiser Permanente's demanding performance requirements."

The decision to use PVB in particular was a result of over two years of exploration and evaluation by Tandus' Research and Development Division.  "At the time, polyvinyl butyral (PVB) was a widely used plastic (primarily as the clear film laminated between glass in automotive windshields and other types of safety glass) but not as a floorcovering," Leonard explained. "Better still, there appeared to be a healthy supply of post-consumer PVB since there are millions of cracked and chipped windshields that are replaced every year. While the recyclers are equipped to recycle the glass components of windshields, there was no commercial use for the PVB flake that resulted as a byproduct until Tandus Flooring developed its innovative process."

In Pharos, Tandus' Powerbond ethos cushion backing earns a relatively high score of 6 in renewable materials for its use of 100% post-consumer PVB, and its ethos backing for modular tile earns a score of 3 for its mixed use of post-consumer and pre-consumer PVB.  Both of these products earn scores of 5 in user toxicity and in manufacturing and community toxics, the highest of any carpet backing evaluated in Pharos to date.

Pharos users can now view other cutting-edge, high-recycled-content carpet backing alternatives. Manufacturers submitted data for each of these backings. After rigorous data quality review processes, we have added these products to our product library in recent weeks:

  • ECORE International, in partnership with Nood carpets, has developed the itstru Technology backing (a.k.a. TRU) made almost entirely (at least 97%) from post-consumer recycled styrene butadiene rubber (SBR). This content earns it the maximum score of 10 for renewable/recycled materials. However, ECORE has not yet identified the balance of this product's ingredients.  According to ECORE International, the formula for this new-to-the-market backing is proprietary; therefore, Pharos is unable to fully evaluate this product's toxicity.  We do know that integral components of SBR are styrene, which was recently listed by the National Toxicology Program as a suspected carcinogen, and 1,3-butadiene, which EPA, IARC and other agencies have long listed as carcinogenic.  ECORE is also seeking Green Label Plus for Nood carpet styles that use this backing.
  • InterfaceFLOR's GlasBac RE backing earns a score of 7 in renewable materials. Over 73% of the backing is made from post-consumer vinyl carpet tile crumb. It also incorporates some post-industrial carpet fiber. However, the presence of diisononyl phthalate -- an EPA-listed Chemical of Concern -- in the vinyl crumb detracts from the backing's manufacturing and user toxicity evaluations (4 and 3, respectively).
  • Shaw Industries, Inc. has developed a custom carpet backing, EcoWorx PX, an alternative to its regular EcoWorx. Instead of post-industrial fly ash, Ecoworx PX contains post-consumer glass and/or residues derived from Shaw's carpet recycling processes.  These residues are primarily calcium carbonate.  This content earns the backing a Pharos evaluation of 4 in renewable materials.  The manufacturing toxicity score for this product, however, fares no better than the standard EcoWorx (2), due to the use of Triclosan.  The State of Oregon Department of Environmental Quality lists Triclosan, a widely used antimicrobial, as a Tier 1 Priority Persistent Pollutant.

Tandus, Shaw, and Interface fully disclosed the material content of these innovative backings. Their data provides Pharos users with all the information they need to evaluate and compare these products' environmental attributes.

Subscribers to Pharos can view the full profiles of these carpet backings and many more in the Building Product Library.  Pharos' multi-attribute scoring allows users to weigh the costs and benefits of these products' environmental and health impacts for their project needs.  We choose not to provide an overall score or ranking for these products because we know that our subscribers may prioritize these values in different ways.  One person's recycled gold may be another's poison.

We are continuing to engage with many carpet manufacturers. The Pharos platform has generated consumer / manufacturer discussions which will improve the recycled content and reduce the health impacts of carpet backings.