The glass-like crystals sometimes found in ready-to-bake refrigerated biscuit dough are not glass, nor are they a consumer hazard. They are a natural byproduct from reactions of the leavenings or baking powders used in the dough to give the baked biscuits the desired volume and texture.
Long storage periods at refrigerated temperatures allow growth of these small, hard, clear crystals. They will dissolve during baking.
Various checks can be performed that will show that these items are not glass. If removed from the dough and left at room temperature and humidity, they will turn opaque and crumbly. They will dissolve in warm water or melt upon heating.
Manufacturers have worked to eliminate or minimize this crystal growth by adjusting ingredient proportions and tightly controlling processing conditions. Although this problem is still seen periodically, the instances are much less frequent than in the early days of refrigerated dough production.