Its often not the lenses that fail the test, but the frames. Especially on chinese made glasses. The lenses are often quite tough even on cheap glasses, but a good off-angle shot to the frame often will crack or outright shatter them.
Just because something conforms to the ANSI 87.1-2003 doesnt mean it cannot perform to a greater standard of protection, but if they don't specifically state that they exceed and by how much, you can only know (and rightly assume) that they pass ansi, and that is the extent of it.
The frames are often the hidden danger.. because people often overlook them.. They see their lenses be scratch free, without notcing the hairline fractures forming in the frames.. until that one errant burst causes them to disintegrate off of your face.
In fact, that is what the fate of my Bolle x800's were. The frame eventually failed, despite the lenses looking brand new.