Can you expand on this? It does look like there are HEPA specifications[0]. Are you saying that a product that doesn't meet those standards can still legally be labeled as HEPA? Yikes!
[0] E.G., http://energy.gov/sites/prod/files/2013/06/f1/doe-std-3020-2... and https://en.wikipedia.org/wiki/HEPA#Specifications