Are all HEPA filters the same?

While researching lead cleanup I read that some HEPA filters are rated to ANSI and other specifications-

Are all HEPA filters rated to these same specs or is HEPA just a marketing term that companies are using to give consumers a warm fuzzy?

I don't see any sort of 'class' or 'rating' along with most HEPAs so where could I even go to find out what specs my HEPA filter meets?