When is oil greener than corn? 3 obstacles to bio-based materials
<p>Over the product life cycle, natural fibers can be less sustainable than some synthetics. Here's an anatomy of a few notable failures.</p>
When I tell people I work for a carpet company known worldwide as a leader in environmental sustainability, the most frequent response is, "Oh, so do you make all of your carpets out of natural materials?"
Interestingly, for Interface, the answer to that question is a clear "no." Other than a nominal percentage of soy and coconut-oil based additives and a few products in Europe, we currently make little use of bio-based ingredients in our carpet tiles. I explain that our focus has been on using abundant waste materials to make our products, but the question remains: Twenty years after we committed to sustainability, why aren't natural materials a bigger part of our materials strategy?
Obstacle 1: Price and performance
Our biggest lessons in the difficulties of working with bio-based materials came in 2001, when we became the first company to use polylactic acid fiber made from corn in a line of carpet tiles. Then a very new plastic, PLA was produced only in a single factory, and was not price-competitive.
In spite of this, we wanted to support the growth of non-petroleum plastics and figured out how to tuft PLA yarn into our products alongside nylon yarn. Had the product line performed well and become a best-seller with an interesting sustainability story, perhaps we could have resolved the many issues — including stability of price and supply — that often plague novel materials.
But the cardinal rule for sustainable product innovation holds: The product must still perform as well or better than the less-sustainable version it is replacing (especially if it costs more). PLA fiber wore out too quickly for use in commercial carpet tile, even shielded by higher rows of durable (petroleum-based) nylon fiber. When PLA started to become popular enough that our supplies were threatened by promises made to other manufacturers, we decided to pull the plug on the experiment.
The performance issue keeps other natural materials more traditionally associated with carpet — such as wool, jute and cotton — from being viable where customers require products to be extremely durable. The dream of a carpet tile that can be used and then tossed on the garden to decompose into perfect fertilizer will remain a dream until we can shift customer expectations for price and/or durability of our products.
Obstacle Two: "Natural" vs. sustainable
While corn-based PLA could not survive the rigors of commercial office traffic, our entry into the residential market with the launch of our FLOR brand in 2003 brought natural materials such as wool back into play. But after experimenting with natural materials, including a line of luxurious wool-fiber carpet tiles, today the FLOR catalog focuses on replicating the look of natural materials such as berber and wool using 100 percent recycled nylon fibers. Why, in products in which durability is not paramount, would a sustainability leader such as Interface switch back to using synthetic materials?
The answer becomes apparent to anyone who has researched natural and bio-based materials: The impacts are not necessarily bigger or smaller than synthetic materials, just different.
We must attempt to compare impacts across the entire life cycle for each material. Agricultural production and associated soil erosion, pesticide use, water pollution and habitat loss associated must be weighed against impacts from mining, drilling and refining of non-renewable resources. When produced at an industrial scale, no material should receive a free pass environmentally. Even the most raw, natural materials, such as wood or stone, can be unsustainable when extracted without limits or precautions.
Using a material such as wool, in use by human herding communities for millennia, now means understanding complex impacts of overgrazing, intensive use of water and chemicals to "de-scale" the wool and the effects of a range of synthetic treatments used to give the wool attributes the sheep never intended, such as bright color, moth repellence and stain resistance. Finished carpet wool is debatably "natural" and not likely to be biodegradable or non-toxic after such treatment.
Tools for assessing bio-based materials provide some assistance and range from in-depth NGO-driven systems that include scoring of biodegradability and toxicity to the USDA Biopreferred Label, which requires only that material come off a farm.
Obstacle Three: Closing the loop
The final obstacle presents the most fundamental challenge; unless we redesign the "take-make-waste" system of how we use our materials, switching to bio-based materials will make very little difference. Interface Americas Chief Innovations Officer John Bradford explains, "It is estimated that the average life span of our plastics, from being extracted as oil, to becoming a product, to the landfill, now takes less than four years to complete. Until we at least extend that cycle, we have no hope of growing enough bio-material to replace our demand for petroleum-based plastics; there is not enough land to sustainably re-grow one quarter of the materials we need every single year."
The challenge is to find ways to use the materials we already have extracted more effectively, which means making sure we have a system that can use them more than once.
Ultimately, the fate of PLA and wool in our products was sealed by the fact that they did not work well in our materials management system. Setting aside performance, price and impacts of producing these raw materials, both wool and PLA would have been contaminants in a recycling infrastructure we designed to recapture the durable plastics in our products.
Bradford believes that right now, bio-based materials can make one significant contribution to our materials strategy: replacing recycled plastics that have become too degraded to be recycled again (typical loss is 2 to 8 percent each time thermoplastics are melted for recycling). The concept is that if we were to keep adding 8 percent compatible, bio-based plastics to a closed loop system every year, that might be a sustainable level of production to expect from plant and algae based plastic feedstocks, and, gradually, over 20 years, we could be using 100 percent plant-based plastics.
This means reimagining bio-based plastics as a transitional "supplement" to existing closed loop plastics management, rather than thinking of them as a panacea that will replace petroleum-based materials overnight and suddenly make our products sustainable.
The more complicated truth about bio-based or "natural" materials is that they are only one potential piece of the sustainable materials puzzle and must be evaluated just as rigorously as any other materials. Even as innovation and sustainability claims explode in the growing bio-based materials space, we cannot forget that no material is sustainable if we fail to manage it sustainably.
Corn image by WayTru via Flickr.