My PackTowl mentions an odor control control treatment, what does that mean?

With our Personal and Luxe towels, we use Polygiene^® odor control treatment to combat the development of odors caused by microbes such as bacteria, fungus, and mildew. Polygiene is based on silver salt (silver chloride) produced from recycled silver, and has a low environmental impact in comparison to other odor-controlling treatments. Because the treatment is integrated into the fabric, it won’t wash out. More information about Polygiene can be found on their website.