RN
One property sorts this entire category, and it is not softness, price or feel. It is whether the surface can be returned to clean.
A non-porous material has no structure below the surface for anything to enter. Wash it and it is genuinely washed. A porous material has microscopic voids, and washing removes what is on top while leaving what has soaked in. Everything else — the lube rules, the condom advice, the shelf life, whether a toy can be shared — falls out of that single distinction.
Why "body-safe" on a listing carries no weight
There is a regulatory gap here that is worth understanding precisely, because it is usually described either too dramatically or not at all.
The strict chemical rules people have heard of — the phthalate restrictions capping certain compounds at 0.1% by weight, the detailed migration limits — are written into frameworks aimed at toys and childcare articles intended for children. Adult products are not covered by those specific instruments. They fall under general product-safety law and the general chemical-registration regime, which apply, but which do not impose a category-specific testing regime the way children's toy rules do.
The practical consequence is that no authority is checking, before a listing goes live, that the material is what the listing says. Academic comment on this is blunt: the health safety of adult novelties is not routinely tested or specifically regulated.
There is now a standard — ISO 3533, first published in 2021, covering design and safety for products in direct contact with genitals or anus. A manufacturer choosing to build to it is telling you something. "Body-safe," "medical-grade" and "hypoallergenic" printed on a marketplace listing are telling you nothing at all, because no definition binds any of them.
That is the entire reason material literacy matters here. You are the inspection step.
Silicone
Non-porous, chemically stable, tolerant of heat, and durable enough that a good piece outlasts the motor inside it. It can be boiled or run through a dishwasher when there is no electronics inside, and it takes texture and firmness variation better than anything else in the category.
The realistic downsides are minor. It attracts dust and lint, which is a storage problem rather than a hygiene one. Good silicone is expensive, and the price gap is exactly what the counterfeit market exploits — a soft, cheap item described as silicone very often is not.
Two clues distinguish it in practice: it has no smell, and it does not go tacky. A material that arrives with a chemical odour or turns sticky in the drawer is not what it claimed to be, regardless of the listing.
TPE and the softness trade-off
Thermoplastic elastomer is soft in a way silicone struggles to match, and it is cheap. That combination is why so much of the market is made of it, and it is a legitimate reason to buy it.
It is also porous. That is not a defect of manufacture, it is the material, and it cannot be engineered away by a better brand. The consequences follow directly:
- It cannot be fully sterilised. Wash it well, dry it completely, and accept that "clean" means clean on the surface.
- It should not be shared uncovered. A condom over the toy, changed between people, is the standard answer, and it is the same answer for moving between body areas.
- It has a service life. Tackiness, a changed smell, a sheen or a darkening patch are the material breaking down. That is a retirement signal, not a cleaning problem.
- Lubricant choice is narrower. Water-based is the safe default; oils and silicone lubricants are the ones with a track record of degrading soft blends.
None of this makes TPE unusable. It makes it a consumable rather than an heirloom, which is a reasonable thing to buy as long as you know that is what you bought.
Glass
Borosilicate glass is non-porous, entirely inert, and unaffected by every lubricant category — the one material in this article with no compatibility table at all. It carries temperature well, which is the main reason people choose it, and a piece with no coatings, adhesives or embedded decoration can simply be boiled.
The caveats are short and specific. Borosilicate is the grade that handles thermal shock; decorative glass is not, and a piece with no stated composition should be treated as decorative. Warm or cool it in a water bath, never a microwave, and check the temperature against your wrist before anything else — glass holds heat far longer than skin expects. Inspect before every use for chips or hairline cracks, and retire a damaged piece immediately rather than considering whether it looks bad enough to matter.
Lubricant compatibility, stated honestly
Water-based lubricant works with all three materials and is the correct default when you are unsure.
The famous rule — never silicone lubricant on a silicone toy — is more contested than its repetition suggests. The mechanism is real for soft blends, and the warning is published everywhere. But a manufacturer-run test across a large set of products reported no degradation on pure silicone components, and the recurring expert observation is that the manufacturing quality of the toy predicts the outcome better than the lubricant category does.
What both sides of that argument agree on is the practical step: test a small amount on a hidden part of the toy, leave it, and check whether the surface has gone tacky or dull before using it properly. That takes a minute and settles the question for the item you actually own, which is more useful than either version of the general rule. Oil-based lubricants are a separate matter and stay away from anything soft, as well as from latex barriers.
Signals worth acting on
Stop using a toy — any toy — if it becomes sticky, changes colour or smell, develops a surface film that returns after washing, or shows a crack, chip or split. Those are material failure, and cleaning does not reverse any of them.
Stop using it, and see a clinician, if you get persistent irritation, unusual discharge, or a reaction that recurs with the same item. A reaction that keeps coming back is information; a new toy is not the fix for it. As with the storage question for latex and leather gear, the material tells you how to look after it, and most of the damage happens between sessions rather than during them.