Are Glass Dildos Safe To Use?
There are three or four things to be aware of, safety-wise, with glass sex toys: that is, toys made of annealed/”pyrexed” borosilicate glass — not glass items that people might choose to play with that are not designed to be sex toys. The latter are not safe to use under any circumstances. If it wasn’t designed/sold as a sex toy and it’s made of glass, don’t use it as a sex toy.
The first safety issue is that the safety/integrity of the glass might be compromised if it is dropped on a hard surface. Personally I would recommend that a dropped glass toy be retired and used as a beautiful paperweight if it is dropped on, say, a tiled or cement floor. Even if the user cannot see cracks, the toy might be affected and suddenly be breakable. If this should happen, it could lead to either of the next two possible issues and make them much worse.
Generally glass is sensitive to changes in temperature. That’s why it’s important that glass toys be “pyrexed”–like Granny’s casserole dish, which can go from the fridge to the oven. A cracked glass toy is no longer protected, so a cool piece of glass going into a warm body orifice is no longer safe if the item has been dropped. (And a non-“pyrexed” glass item is dangerous for this very reason.)
While sex toys are made of very hard glass, if they’ve been dropped, moving around a lot with them inside body orifices is the most dangerous scenario. This puts not just temperature stress on the item, but pressure stress. Obviously an internal break with a glass toy is a worst-possible scenario and must be avoided at all costs.
Even if the glass toy has NOT been dropped/compromised, it will be about as hard and inflexible as metal. And so this part of the answer goes for metal toys too. It is more relevant to dildos than the anal plugs, because the dildos are longer. Trying to sit up with an inflexible item in the rectum, particularly a long one, could be dangerous because the item is not able to bend; it could be painful, if it’s long enough to reach the coccyx/tailbone it could put pressure on it through the rectal wall and bruise it. Worst-case scenario would be tearing, or (if the glass was in fact compromised) breakage. (Vaginal use is not as dangerous but the pain/bruising issue could be relevant there too.)
So when people use a hard plastic/lucite OR glass OR metal toy, especially anally, they should remove the toy before changing positions from, say, lying flat to sitting up. Again, a short toy like a plug is not especially dangerous here — it is the longer dildos that can go deeper and put pressure against the rectal wall/coccyx that I’m especially talking about.
In other words, know your toys AND know your anatomy! Once you do, you can use glass toys safely.