Safety glass can be toughened or laminated, and each glass can be more suitable for different apertures. For shelves and places that require exposed edges, toughened glass can be polished to give a safe professional finish. Toughened glass breaks into tiny harmless pieces that won't cause serious injury. Laminated glass is 2 pieces of glass that holds to together with a clear film when broken. This is much harder for burglars to get through and so is good in double glazed units or single glazing in properties.