Wool is Biodegradable
January 26, 2018

The International Wool Textile Organization released this month a new fact sheet on the biodegradability of wool. A biodegradable product can be broken down biologically into natural raw materials such as carbon dioxide, water and naturally occurring minerals. These are then reintegrated into the nutrient cycle. Conditions needed for products to biodegrade are oxygen, warm temperatures and humidity.

Wool grows naturally on sheep, and is made of a protein called keratin – the same protein that is in human hair. During the biodegradation process, fungi first destroy the ends of the wool fiber. Bacteria then digest the weakened fiber by secreting enzymes. The carbon-to-nitrogen ratio of wool is quite narrow, meaning that wool has a high percentage of nitrogen. This high percentage of nitrogen is the reason wool biodegrades so well.

In most tests, a wool product such as a jacket is buried in soil which provides the necessary microbes, moisture, temperature and pH-value. To retrieve the garment more easily, it is placed between two wire grids. After a certain period of time, the test garment is dug up in order to observe and document the decay. Tests show that with the ideal conditions, wool products are almost completely degraded after six months in the ground. Seams may not degrade as easily as the rest of a garment, because they consist of a double (hence thicker) layer of fabric and are often sewn with polyester thread. The dyes used on a wool product do not impact the results.

Products made out of synthetic fibers can take 30 to 40 years to degrade, contributing to the ever-increasing piles of waste in landfills. Because it naturally degrades in a fraction of that time, wool is the obvious choice for anyone concerned about the health of our planet.

Source: IWTO