3p Weekend: 6 Lesser-Known Uses for (Sustainable) Cotton

With a busy week behind you and the weekend within reach, there’s no shame in taking things a bit easy on Friday afternoon. With this in mind, every Friday TriplePundit will give you a fun, easy read on a topic you care about. So, take a break from those endless email threads and spend five minutes catching up on the latest trends in sustainability and business.

Cotton is one of the most widespread and lucrative commodities on earth. Its production supports 250 million people's livelihoods and employs almost 7 percent of all labor in developing countries.

But the billion-dollar industry finds itself under the microscope, as critics point out environmental and human-rights concerns in its supply chain. With this many people depending on the crop, it's clear that eliminating its use isn't the answer. Efforts such as the Better Cotton Initiative seek to improve cotton-farming practices, limit environmental damage and prevent labor abuses. Proponents say programs like BCI can improve the cotton supply chain while ensuring people's livelihoods.

This fall, TriplePundit will run a series in partnership with Cotton Incorporated to examine how this transformation will take place. In many cases, say trade groups like Cotton Incorporated, the solution is finding more applications for cotton, not less.

Consider this: One 480-pound bale of cotton yields approximately 740 pounds of seed and up to 200 pounds of other waste. If lucrative end-uses are developed for these secondary materials, farmers can sell them and turn waste into profit. On a sustainable farm, investments from these new revenue streams can translate to further improvements in farming practices.

And while most of us think of cotton as the main ingredient in our jeans and T-shirts, the crop has a variety of untapped applications across multiple sectors. Let's take a closer look at six of them:

1. Medicine

In 2010, researchers from the National Institutes of Health published a paper on what they called a "promising agent" against prostate cancer. Their research centered around gossypol, a cotton phenol that serves as a natural pesticide. They determined that gossypol reduced the viability of some cancer cells, without harming healthy cells, and could also slow the growth of tumors.

Another study published three years later in the journal Nature found similar results using gossypol to treat pancreatic cancer, in tandem with another agent. And researchers with the University of Kansas Cancer Center began early-phase clinical trials using gossypol to treat prostate cancer earlier this year.

It may sound crazy to think the stuff that's in your jeans could treat cancer, but that could be the wave of the future. And any agent that can prevent more people from losing a loved one to this indiscriminate disease is surely good news.

2. Food for people

As she's known to do, Vani Hari (aka the Food Babe) popped into the headlines again last May. This time her gripe was with cottonseed oil, saying bluntly: "This ingredient isn't food."

James Pruden, director of public relations for Cotton Incorporated, begs to differ. He posted a point-by-point rebuttal to Hari's argument on the company's Facebook page, saying simply: "Cotton is regulated as a food crop in the United States." Even Fortune magazine took notice of the dispute, saying of Pruden and Cotton Incorporated: "Their product is soft, but they have bolls of steel."

Yes, those who are concerned about GMOs and pesticide application may have some qualms with cottonseed oil. But the same can be said for other food crops we consume far more regularly. (We're looking at you, corn and soy!) And due to its high smoke point and neutral flavor, cottonseed oil makes sense for a number of cooking applications.

Whole cottonseed is also promising a human protein source, particularly as the global population is projected to hit 9 billion by 2050. In 2013, Forum for the Future noted cottonseed's potential as a food source. But there's a hitch: Gossypol, the same agent being tested for cancer treatment, can be toxic if ingested at high doses. Gossypol is removed from cottonseed oil during the refining process. But more research is needed to optimize cottonseed production and cultivation for human consumption.

3. Food for animals

More than 30 percent of the calories produced by the world's crops are used for animal feed. Corn is the primary U.S. feed grain, according to the U.S. Department of Agriculture. It's also a staple the human diet. And as we climb to 9 billion, we must use more of our acreage to feed people, not animals. Using waste materials from commodity crops like cotton can help in this area.

Cotton waste, such as stems and hulls, is perfectly nutritional for beef cattle if used as part of a balanced diet. Whole seeds are also packed with protein and provide an "excellent supplement to poor quality grass and hay" for dairy cows, say researchers from the University of Georgia Extension.

And cows aren't the only animals that have a taste for cottonseed. Last year Tracey Carrillo, a professor from New Mexico State University, turned heads for raising jumbo shrimp in the desert. Raised in aquaculture tanks and sold via a student-run company, the shrimp reached their impressive size on a mostly cottonseed diet. The shrimp farm is part of a broader project with Cotton Incorporated to expand end-uses for cotton.

“When cotton is running 60, 70, maybe 80 cents a pound for the lint, and if you can add a buck a pound or $2 per pound for the seed, then we’ve significantly increased the value of cotton production,” said Carrillo, assistant director of NMSU campus farm operations.

4. Biodiesel

Cottonseed oil, like other cooking oils, can be converted into biodiesel. And recent research concluded that cottonseed oil is an effective drop-in fuel for existing diesel engines. Of course, now that we've established that cottonseed oil can be used for food, the good ol' food-versus-fuel debate rears its ugly head once again.

But waste oil is also an option. A study published this spring focused specifically on waste cottonseed oil. Researchers noted a "reduction carbon monoxide and hydrocarbon emissions" with waste cottonseed biodiesel, albeit with a marginal increase in nitrogen oxides. They concluded, "Biodiesel produced from waste cotton seed oil possess a great potential for being source of alternate fuel." Not too shabby.

5. Insulation

The cotton fibers used in clothing can often be recycled into new garments. Levi's new line of jeans made from post-consumer cotton offers plenty of evidence to that effect.

But it can become challenging to extract cotton for closed-loop recycling when it is blended with other fibers. In this case, the blended fiber is often recycled into non-apparel products -- the most common being household and building insulation. The Blue Jeans Go Green program, for example, collects old jeans and transforms them into insulation for Habitat for Humanity houses.

Levi's also turned to jeans to insulate its Bay Area HQ: “There are 25,500 pairs of old denim jeans used in the insulation in our headquarters building in San Francisco," Michael Kobori, Levi’s vice president of global sustainability, told TriplePundit in 2014. "It is actually a better insulator than fiberglass.”

He's not wrong. Even home improvement guru Bob Vila touts the benefits of recycled denim insulation, noting its durability, improved sound absorption, and high air-quality rating compared to fiberglass.

6. Mulch

Okay, so this one may not sound so surprising on the surface. Cotton is a plant, so it makes sense that you can chop it up and compost it. But emerging applications for cotton mulch could actually save cities big bucks.

Namely, city planners are looking to reduce wind and water erosion along roadways. Roadside vegetation is widely used for its erosion-busting benefits. And it turns out compost made from cotton waste, such as stems, leaves and hulls, can help.

In 2011, researchers from Texas Tech proclaimed: "Cotton waste used for compost has huge market potential for the establishment of roadside vegetation." But they noted a lack of research into the effect on soils. After testing, they found cotton compost applied as a top-cover improved the soil's water retention without negatively affecting other properties.

Another cost-saving benefit of cotton waste mulch is that it can be used in spray-on applications. Often called hydromulch, the green slurry can be sprayed on roadsides, as well as construction sites, to slow erosion.

Image credit: Flickr/Kimberly Vardeman