Glass dildos are made of borosilicate glass, which is incredibly strong. Ever used Pyrex bakeware? It's the same thing. My Pyrex measuring cup will bounce on my kitchen floor and not even shatter. If borosilicate glass did break, it'd break into large chunks, not splinters and shards. I've never ever heard of one breaking in use or with appropriate care. Under extreme conditions, like dropping them 10 feet onto concrete, they may break. I've had mine tumble down concrete steps and not even have a scratch on them. Just be sure to check them for scratches or chips before use and they're perfectly safe.