What Is Medical Grade Liquid Silicone Rubber?

What Is Medical Grade Liquid Silicone Rubber

I know you are probably wondering what is unique about medical grade liquid silicone rubber. In this guide, you will find all information you are looking for about medical grade LSR – from the definition, classification, features, and benefits to disadvantages.

Let’s dive right in.

What is Medical Grade LSR?

Medical grade LSR is a silicone that is usable for medical applications, as it is tested for biocompatibility. Ideally, these liquid silicone rubbers are approved by FDA use for medical and food industries.

It is made of thermoset material with low viscosity and is elastic and strong. The chemical, electrical and thermal resistance of this type of silicone makes it a choice material for medical applications.

Examples include the production of:

  • Menstrual cups
  • Food
  • Mouthpieces
  • Skin contact products
  • Baby bottle nipples.

Figure 1 Medical grade liquid silicone rubber

Medical Grade Liquid Silicone Rubber

Three Categories of Medical Grade LSR

When it comes to choosing suitable medical grade LSR, you can choose from limited exposure, prolonged exposure, or permanent contact.

Let’s look at each variation in detail:

Limited Exposure

This type of medical-grade silicone is best for short-term applications. This includes the production of items that come into contact with the mucosal membrane, skin, or breached and compromised surfaces.

You can get exposure to this type of medical-grade LSR for less than 24 hours.

Prolonged Exposure

This is also known as the healthcare grade LSR. It undergoes tests such as:

  • Toxicity
  • Genotoxicity
  • Hemolysis
  • Intramuscular implantation

Prolonged exposure medical grade silicone is usable for a longer time than the limited exposure LSR. You can comfortably withstand up to 30 days of exposure to healthcare-grade LSR.

Permanent Contact

This long-term implantable type of silicone goes through biological and physicochemical testing. The tests are far more rigorous than those done on the prolonged exposure type.

They include

  • Developmental toxicity
  • Chronic toxicity
  • Carcinogenicity

Features Of Medical Grade Silicone Rubber

There are many reasons why medical grade LSR is popular today. These include:

Figure 2 Silicone medical accessories

Silicone Medical Accessories


Thorough testing proves that medical-grade silicone rubbers are more compatible with human body fluids and tissues. They also have a very low tissue reaction than other elastomers upon implantation.

It is colorless and odorless. It also does not give space for bacterial growth, nor does it corrode or stain other materials.

Medical grade LSR is manufactured in compliance with the Tripartite, ISO, and FDA biocompatibility guidelines in place for medical products.

Temperature Resistance

LSR can withstand more severe temperatures than other elastomers. It can even remain stable when exposed to temperatures between –75° and 500°F.

Sterilization of LSR is through various methods such as steam autoplaying, E-beam or gamma irradiation, and EtO gas.

Chemical Resistance

Medical-grade silicone rubber is resistant to chemicals and water, including ammonia, oxidizing chemicals, isopropyl alcohol, and some acids. It also can’t mix with solvents and strong acids.

Mechanical Properties

Its mechanical properties include:

  • Difficult to tear
  • Very strong
  • Good elongation
  • Flexible
  • Low compression
  • Very durable.

The silicone’s softer parts can keep their softness for indefinite periods.

Electrical Properties

Silicone is excellent insulator compared to other materials. It is used for various electrical applications and does not conduct electricity.

It keeps its dielectric strength, even in extremely high or low temperatures than standard insulating materials.

What Makes Medical Grade LSR Safe?

Medical-grade silicone does not react in its environment and is biocompatible. It can get into contact with any part of the body without releasing any particles. This makes it safe for use in the human body.

Advantages Of Medical Grade Silicone Rubber

The advantages of choosing medical-grade silicone rubber over other materials include the following:

  • Medical grade LSR is used in many medical applications that require contact with human skin.
  • It is very stable and water-repellant to prevent the effects of a cured material in touch with the skin.
  • Compared to other materials, it is non-allergenic and does not affect the skin.
  • Its hygienic quality makes it resistant to the growth of fungi and bacteria.
  • The patient’s comfort is guaranteed, as it is soft and flexible.
  • Its water-repellant properties keep it from adhering to wounds.
  • Medical-grade silicon rubber is resistant to very high and low temperatures while maintaining its elasticity.
  • The medical grade LSR compression set is meager and difficult to deform when applied or forcefully removed.
  • Highly resistant to ultraviolet radiation.
  • Has a very long lifespan, thanks to its cured parts.


Medical-grade silicone rubber is a versatile product suitable for many medical applications. It is an excellent choice, as it allows no compromise where human health is concerned. When used correctly, it plays a major role in the health of a patient.

More Resources:

Injection Molding LSR – Source: LegenDay

Where does Silicone Rubber Come from? – Source: LegenDay

Liquid Silicone Rubber Overmolding – Source: LEGENDAY

Step-by-step Liquid Silicone Rubber Injection Molding Process – Source: LEGENDAY

Top 10 Liquid Silicone Rubber Manufacturers in the World – Source: LEGENDAY

Why only Hollow LSR parts Float on Water – Source: LEGENDAY


Update cookies preferences
Scroll to Top