Written and maintained by CASRAI Editorial Board
Last updated
General product information, not medical advice. For a specific device, follow its labeling and the instructions of the clinician who prescribed it.
Overview: silicone types are defined by how they cure and what form they take
Silicone is not one material. In medical supplies and lab equipment the useful way to sort it is by cure chemistry (platinum addition, peroxide or condensation) and by form (room-temperature-vulcanizing sealants, solid heat-cured rubber, or liquid silicone rubber for injection molding). The word “medical grade” on a product page does not replace the device’s own labeling: FDA’s guidance on ISO 10993-1 frames biological evaluation around the component materials of the finished device in contact with the body, not around a material name alone.
This page is for buyers, clinic staff, caregivers and lab staff who need to read a product description or datasheet and tell what kind of silicone it describes. Comparable materials are covered in TPE vs TPU and What Is Butyl Rubber?.
Types table: what each silicone type is, best for, and limits
| Type | What it is | Typical uses | Limits to know |
|---|---|---|---|
| RTV-1 (one-part room-temperature vulcanizing) | Supplied ready to use; cures by reacting with moisture in the air. Xometry notes that some cross-linking agents give off small amounts of acetic acid, amines or alcohols while setting. | Sealants, bonding glues and coatings (Xometry). | Cure byproducts depend on the cross-linker. |
| RTV-2 (two-part) | Two components mixed before use. Condensation-cured RTV-2 is less expensive than platinum-cured RTV-2; platinum cure creates no byproducts (Xometry). | 3D printing, coatings and molds (Xometry). | The cure system (condensation or platinum) has to be named to know what you have. |
| HCR / HTV (high-consistency or high-temperature-vulcanizing solid rubber) | Solid, heat-cured rubber supplied as base stock or compounds. WACKER lists two families: peroxide-curing (ELASTOSIL R) and platinum-catalyzed addition-curing (ELASTOSIL R plus). Xometry says HCR can be cured with peroxide or platinum, and that platinum cure leaves no byproducts. | Tubing, seals and gaskets (Xometry). RAUMEDIC states that tubing made from peroxide silicone is used in various medical pumps. | The cure system (peroxide or platinum) has to be named to know what you have. |
| LSR (liquid silicone rubber) | A two-part, platinum-cured raw material with good fluidity, used for injection-molded parts and coatings (Xometry). RAUMEDIC makes LSR parts such as connectors and gaskets, including parts molded onto tubing. | Precise molded components. RAUMEDIC says LSR, as an addition-crosslinked platinum silicone, has very good biocompatibility (manufacturer claim). | A manufacturer’s biocompatibility statement applies to its own product, not to every LSR part. |
| Fluorosilicone | Silicone in which some methyl groups are replaced by trifluoropropyl groups, giving better resistance to fuel, oil and organic solvents such as toluene (Xometry). | Aerospace and automotive, where fuel and chemical exposure is likely (Xometry). | Xometry says it does not perform as well in hot air as conventional silicone. |
Cure chemistry in plain terms: platinum, peroxide and condensation
Platinum (addition) cure. The platinum in the silicone acts as a catalyst during cross-linking (RAUMEDIC). Xometry says platinum cure produces no byproducts, and RAUMEDIC describes addition-curing platinum silicone as exceptionally suitable for applications with very strict requirements. RAUMEDIC uses addition-curing platinum silicone for implant tubing.
Peroxide cure. RAUMEDIC reports that cross-linking in peroxide silicone is higher than in platinum silicone, giving better recovery in peristaltic or roller pumps, which is why peroxide tubing is used in various medical pumps. It also states that both tubing types are temperature resistant from -50°C to +200°C (manufacturer figure for its tubing, not a rating for every silicone product).
Condensation cure. Xometry names condensation cure for lower-cost RTV-2, compared with platinum-cured RTV-2.
How to choose: the same check in home care, clinic, hospital and lab
The deciding document is the same in home care, clinic, hospital and lab: the labeling or instructions for use of the specific item. This table maps the question a reader usually has to where the answer sits.
| Question | Where the answer sits |
|---|---|
| Is it silicone, and which cure type? | The manufacturer’s datasheet or product page. Cure type is a stated property (platinum, peroxide, condensation). |
| Is this item evaluated for contact with the body? | The device labeling and the maker’s statement about biological evaluation. FDA’s ISO 10993-1 guidance concerns the finished device’s contact with the body. |
| Is it a pump tubing, seal, gasket or molded part? | RAUMEDIC describes pump tubing in peroxide silicone and platinum silicone, and connectors and gaskets as LSR injection-molded parts; the item’s datasheet states which applies. |
| Does it need a biological-testing certificate such as USP Class VI? | See USP Class VI certification for what that label does and does not cover. |
What to check on the label
- The material and cure type, not just “silicone”. “Platinum-cured” and “peroxide-cured” are different products.
- Who makes the biocompatibility statement. A manufacturer’s claim is an attributed claim for its own product.
- The intended use stated in the instructions for use: tubing in a pump, a seal in lab equipment, or a body-contact device are different contexts. The earmold types guide shows how platinum-cure and heat-cure silicone appear in one device category.
- Latex-free wording only if the label itself says it. Do not infer it from the word silicone.
Care and replacement
Cleaning, sterilization and replacement intervals are set by the manufacturer’s instructions for use for that specific product, not by the word silicone. For lab items, which plastics are autoclavable covers material-by-material sterilization compatibility for common lab plastics.
FAQ
What are the main types of silicone?
Xometry’s article covers four common types: room-temperature-vulcanizing (RTV, one-part RTV-1 and two-part RTV-2), liquid silicone rubber (LSR), fluorosilicone and high-consistency rubber (HCR). They differ in how they cure and how they are supplied.
Is platinum-cured silicone different from peroxide-cured?
Yes. Platinum addition cure uses a platinum catalyst and, per Xometry, leaves no byproducts. Peroxide cure gives higher cross-linking and, per RAUMEDIC, better recovery in pump tubing.
Does “medical grade silicone” mean the product is biocompatible?
Not by itself. FDA’s guidance describes evaluating the component materials of the finished device for the potential for an unacceptable adverse biological response, so the finished device’s labeling is the reference.
Is silicone rubber the same as a sealant?
No. RTV-1 sealants cure from moisture in the air, while solid silicone rubber (HCR/HTV) and LSR are heat-cured or injection-molded materials.
Sources
- FDA, Use of International Standard ISO 10993-1, Biological evaluation of medical devices (September 2023), checked 2026-10-30.
- RAUMEDIC, Silicone material expertise (manufacturer), checked 2026-10-30.
- WACKER, Solid silicone rubber (manufacturer), checked 2026-10-30.
- Xometry, Types of Silicone (vendor article), checked 2026-10-30.
