High velocity impact safety glass test method is performed by shooting a 1/4" steel ball at a speed of 150 feet per second aimed at the center of the lens. The result is a Pass or Fail which determines that a lens must not chip, break, or crack and it must maintain its original position in the frame.
ANSI D3 SPLASH
Eye protection rating for protection from liquid splash hazards
ANSI D4 DUST
Eye protection rating for prevention of dust hazards from entering the eye