As long as it is a solid piece and not previously cracked, glass is as safe as can be. Glass is actually a very hard material. Of more concern are rubber buttplugs. No matter how assiduously they are cleaned, rubber is porous and ends up absorbing minute traces of bodily fluids, dust, germs and chemicals from cleaning products. All these can lead to serious infections. Please remember that the lower digestive tract absorbs freight matter into the blood stream faster than the mouth, or the lungs.Originally Posted by AndrewBlack