In the creation of our Happy Knees mat we made it a point to be environmentally responsible. We wanted to create a mat that would address comfort and a non slip surface without compromising the environment. Thus, we decided to use natural rubber for the surface of the mat. Natural rubber will decompose and return back to the environment while still allowing you to have a comfortable surface. Yes, this means that the Happy Knees mat will not have the strong smell found in the unnatural composites that are being formulated and used to make many mats. This is turn means that you will not be inhaling chemicals when you are lying down on your mat. What this means in turn is that you will help maintain a healthy body free of chemicals. However, our mats surface will not lost as long as those surfaces made with unnatural composites. Think of the surface of our mats as that of a great pair of running shoes. I'm a runner and go through 2-3 pairs of running shoes a year. However, you should have the Happy Knees mat lasting you a year if you practice yoga 2-3x a week. For those who are using the mat for stretching only, it will lost you 3-5 years. One thing that we highly recommend is that you don't throw the mat in your watcher as it is made of natural rubber. The best way to clean it and keep it free of germs and fungus is to make a tea tree oil, water, and lemon solution. Pour 16 ounces of water to 3-4 drops of tea tree oil and a few lemon drops into a spray bottle. Lightly spray your mat with this solution and lightly wipe it down and let it dry naturally and it will kill any germs and fungus without destroying the natural rubber. Namaste!