Can a paraglider rescue chute and its pilot handle terminal velocity?
I have been told in person by the owner of High Energy Sports, a well-known manufacturer of hang gliding / paragliding emergency parachutes, that their products are not designed to be safely deployed at the terminal velocity of a falling human being.  Regardless of what some particular standard might suggest, I doubt that any hang gliding or paragliding emergency parachute is really designed to have a robust safety factor in the context of deployment in a true terminal-velocity freefall.  The greatest concern would seem to be catastrophic failure of the parachute and/or harness, not injury to the user due to opening shock, but the latter would seem likely to be a possibility as well.  

Keep in mind that a hang glider or paraglider pilot does not actually cut away from the rest of their equipment (e.g. the main canopy of a paraglider) before deploying their emergency parachute.  There is no way to easily do so.  And that is why the reserve parachute is not designed for a terminal velocity freefall.  (Edit: see other answer for an exception-- apparently some paragliding rigs are designed to allow for a cutaway.)

Nonetheless, in an article in "Hang Gliding" magazine from well over ten years ago, well-known test pilot Mark Stucky described an incident from his younger days when he went skydiving using his hang gliding emergency parachute.  I don't recall whether the article specified how long he waited before opening the parachute and whether or not he might have been anywhere near the maximum terminal velocity of a falling human being-- one would tend to assume not.  He did survive without injury.   

See also answers to related question Whats the difference between a paragliding rescue chute and a parachute?