Glass (borosilicate)

High-quality glass, it is heat-resistant (like the one in your oven) and cools very well. It’s also resistant to breakage, so there’s no risk of ending up with pieces when you insert it.
It’s non-porous, easy to clean and can be used with any type of lubricant… In short, it’s the best.
Unfortunately, there are some good ones and some not so good.
Good quality glass sex toys won’t give you any trouble. That’s because they’re made in two stages: heating the material to its melting point to mould it, then soaking it to make it harder.
If your toy cost you almost nothing, beware. It’s possible that it’s just glass that’s been heated in a mould and that’s all…

Without tempering, it’s much less solid, so make sure you check the description of the sextoy to see if it’s tempered glass.

After that, the risk is more of breaking it if you drop it than of breaking it during recreational use.