PI-31 / Reference
Material guide
Seven materials, four properties each. This is a reference table rather than an article: consult the row for whatever is in your hand, then read the notes underneath if the answer needs explaining.
Porosity is the property that decides most of the others. A non porous surface can be cleaned properly, because there is nowhere for fluid to hide. A porous surface holds fluid inside the material, where nothing applied to the surface reaches it, which is why porous items cannot be sterilised at any temperature or with any product.
| Material | Porosity | Heat tolerance | Cleaning | Avoid |
|---|---|---|---|---|
| Platinum cured silicone | Non porous | High. Boilable if solid and without a motor | Warm water and mild unscented soap; boil occasionally when solid | Silicone lubricant, storage in contact with other silicone, sustained heat, abrasive cleaners |
| ABS plastic | Non porous | Moderate. Softens well below boiling | Warm water and mild unscented soap; wipe dry | Boiling, dishwashers, acetone and solvent based cleaners |
| TPE and TPR | Porous | Low. Deforms with heat | Surface wash only; dry fully; a condom over it for sharing | Boiling, sharing without a barrier, anal to vaginal transfer, oil, long storage |
| Borosilicate glass | Non porous | Very high. Boilable; tolerates deliberate warming and cooling | Warm water and mild unscented soap; boil when a higher standard is wanted | Impact against hard surfaces, extreme thermal shock, continued use after any chip |
| Stainless steel | Non porous | Very high. Boilable; holds temperature for a long time | Warm water and mild unscented soap; boil when wanted | Very hot or very cold water immediately before use, plated rather than solid items |
| Sealed hardwood | Non porous while the seal is intact | Low. Heat and water damage the finish | Wipe with a damp cloth and mild soap; dry at once; never soak | Soaking, boiling, any use once the finish is scratched or worn |
| Jelly, soft PVC | Porous, and often plasticised | Very low. Softens and deforms readily | Surface wash only; a condom over it is the sensible minimum | Internal use without a barrier, sharing, heat, oil, any item that smells strongly or feels tacky |
Notes on the rows
Silicone. The platinum cure is a cleaner curing process than the older tin cure and leaves fewer residues. The material is inert, warm to the touch and forgiving. Its two vulnerabilities are chemical rather than physical: silicone lubricant swells and permanently damages the surface, and prolonged contact with another silicone item can cause the two to react and bond at the point of contact.
ABS. The rigid glossy plastic used for handles, bullets and hard shafts. Completely non porous and easy to clean. It has no chemical vulnerabilities in ordinary use, but it deforms with heat, so boiling is out.
TPE and TPR. Soft, stretchy and widely used, which is why they dominate sleeves and squeezable items. They are porous, they degrade over time and they cannot be sterilised. Used with a barrier, kept to one person and replaced periodically, they are workable rather than ideal.
Borosilicate glass. Strong, smooth, entirely inert and compatible with every lubricant. Its thermal resistance is what allows deliberate temperature play. Inspect it before every use: a chip makes the item unusable permanently.
Stainless steel. Grade 316 or 304 for internal use. Heavy, rigid and excellent at holding temperature, which is both its appeal and its main hazard: a steel item left in hot water will hold that heat far longer than expected, so test it against a wrist first.
Sealed hardwood. Uncommon but genuine. The wood itself is porous; the sealant is what makes the object non porous, so the object is only as safe as its finish. Once the finish is compromised the item should be retired.
Jelly and soft PVC. Soft PVC needs plasticisers to stay flexible, and those plasticisers are not chemically bonded to the polymer, so they migrate out over time. That migration is the source of the smell, the oily film and the eventual stickiness. This is the group to leave behind.
The reasoning behind the whole table is set out at length in body safe materials, and the washing procedures in cleaning and storage. For lubricant against material, use the compatibility table.