Stainless steel is considered to be hypoallergenic for most people. This way, you can ensure that your glass sex toys are truly bacteria-free, which is great if you’re a bit anal… get it? This robustness means that you can boil a sex toy in water without worrying about the glass cracking. No, your ass isn’t 400 degrees, don’t worry. Sex toys made from borosilicate glass are designed to withstand extreme temperatures. These materials are much less safe for your body, so we would suggest replacing them with medical-grade silicone alternatives if possible. You’ll find a lot of sex toys made from PVC, “jelly”, TPE and TPR – sometimes these will often even be referred to as “silicone” even though they’re technically not. As the name suggests, this silicone is designed to be safe for use inside the human body, which includes shoving it up your ass! If you’re looking for high-quality material which won’t let you down, we would highly recommend medical-grade silicone.