Textile products at the end of their useful lives often end up buried in landfills, where water combines with eager microorganisms to break down organic molecules in natural fibers and polymers. This natural decomposition process generates carbon dioxide as a waste and also releases organic molecules to the soil while rotting away the volume and mass of the product. But what happens during the decomposition of textile products with coatings, surface treatments or synthetic polymers containing carbon-to-carbon molecule links that fungi and bacteria can’t “eat”? The Hohenstein Institute, Bönnigheim, Germany, can create individual test plans to evaluate the ecological impacts of product breakdown, using a range of techniques.
The institute uses a soil burial test governed by international standards to evaluate textile breakdown and determine how quickly and completely microorganisms work. Evaluating the residue is trickier, and can be costly and impractical. The Hohenstein Institute tests the residue, with all of its combined breakdown products, on sensitive biological organisms to assess potential environmental harm. The method uses marine bacteria, water fleas and fish eggs, among other things, and tests whether the residue has adverse effects on living things.
Everyday products, such as clothing or home furnishings, should break down in soil quickly without leaving harmful residues. Geotextiles used to reinforce embankments or dikes, however, need to resist decomposition in wet environments for as long as possible. Among those seeking individual test plans are producers of prefabricated automotive parts and chemical coatings, as well as recycling companies looking for better waste management techniques.