I love the Home Solutions bags! It's my understanding they are a new form of paper mixed with fibers and provide excellent filtration. The truth is, Perfect bags are made in China and are not subjected to the U.S. Dept. of Energy specs. In fact, there is no U.S. govt. agency that regulates HEPA outside of the Dept. of Energy. Vacuum cleaners can "decide" to call thier bags, filters, and machines "HEPA" even if they fall short of the Dept. of Energy's regulations. There is no law that says they must conform, but many manufacturers do have thier equipment tested to make sure it does. Vacuum bags claiming "HEPA" filtration can redefine it to mean "Highly Effective Particulate Air" which falls short of govt. standards. Shady yes, but nonetheless true.