When I opened up Facebook and saw that I had received a question from the beautiful and talented Judith, I was ecstatic. As I continue to be.  

Judith discovered some fancy man-panties and posited: “Tencel is a fiber made from the pulp of Eucalyptus trees… my favorite Materials Girl, do tell me: does this make the said underwear edible? Should these men be concerned about vicious attacks from hungry koalas?”

In short: no, and yes very. But you didn’t click all the way here for pithy humor, you came for science, so here it comes…

Tencel® is an interesting hybrid of natural and synthetic. Let’s start with the precursor to Tencel®, Rayon. Rayon, is derived from cellulose which is in eucalyptus trees, bamboo, cotton, or any woody plant. In order to harvest the cellulose the wood is subjected to a long and involved series of treatements that are chemical and energy intensive, as well as hugely toxic. Rayon processing is so nasty that it isn’t allowed in the United States. (air and water emissions: ) Think about it this way, cotton grows in fiber form, each cotton puff is comprised of hundreds of individual fibers from just under an inch to an inch and a half long. Now think about a pine tree, where are the fibers? There aren’t any. The following (awesome) image shows how sheets of wood turn into fibers.

(image: fiber source)

After this whole process the cellulose has been dissolved into a solution that can be spun into fibers, similar to other synthetics. To over simplify we’ve put a tree in a blender, dissolved it down with chemical reactions and ta da! Processable goo. This is the same exact process used in “eco” bamboo fabrics, which are a complete lie. Bamboo is a fast growing grass and a great source of replenish-able resources, but this benefit is counteracted by the processing it undergoes when used as a fiber.  

Lenzing, the makers of Tencel®, have developed a closed loop system that doesn’t pollute the environment during processing and production, they use organic solvents and have a 99.5% reclamation rate. Though I have my doubts, they are Oeko-Tex 100certified which is significant, and highly reputable. 

So Judith: No, Koalas wouldn’t even recognize their favorite treat by the time it hits the underwear drawer. But hopefully the environmentally motivated consumer will recognize the need for science in making their shopping choices.