SSP2390 silicones are high-purity medical silicones for medical devices, medical equipment, and food-contact applications. Because they are platinum-cured, these USP Class VI silicones have stronger physical properties and lower shrinkage values than peroxide cured compounds.
SSP ships our medical silicones platinum pre-catalyzed and ready for use. Choose moldable compounds, sheet stock, or rolls from .005″ to .250″ thick. Among its many advantages, SSP2390 is available in a range of durometer-based grades (10 to 80 Shore A).
Product | Shore A | Tensile (psi) | Elongation (%) | Tear B (ppi) | Specific Gravity |
SSP2390-10D | 11 | 370 | 990 | 90 | 1.08 |
SSP2390-20D | 21 | 640 | 910 | 135 | 1.09 |
SSP2390-30D | 30 | 950 | 890 | 150 | 1.10 |
SSP2390-40D | 39 | 1310 | 840 | 165 | 1.12 |
SSP2390-50D | 48 | 1510 | 770 | 165 | 1.14 |
SSP2390-60D | 59 | 1500 | 770 | 215 | 1.17 |
SSP2390-70D | 72 | 1390 | 720 | 220 | 1.19 |
SSP2390-80D | 79 | 1310 | 670 | 160 | 1.21 |
Platinum-cured silicones are cleaner than peroxide-cured silicones, but choosing the right elastomer is about more than the cure system. Some medical silicones need to meet USP Class VI requirements. Samples of SSP-2390 have been USP Class VI certified by an independent laboratory.
SSP2390 meets FDA, USP Class VI*, and RoHS requirements. SSP’s medical grade silicone is normally translucent; however, we can also supply these elastomers in colors such as red, black, gray, and white.
*The base material in SSP2390 meets USP Class VI requirements, but pigments used in custom pantones need separate testing per color by the end user. It is the responsibility of the end user to determine materials suitability and compliance with regulatory requirements.
USP Class VI silicones are biocompatible elastomers that have low levels of extractables, chemicals that can migrate from a material at elevated temperatures or with surface exposure. Items made from USP Class VI silicones cannot be implanted within the human body for longer than 29 days. Consequently, most applications involve contact with skin and living tissue.
Certified USP Class VI silicones are silicone materials that have passed a specific set of biological tests defined by the United States Pharmacopeia (USP), specifically Class VI.
USP Class VI is a classification for plastics and elastomers (including silicones) that ensures the material is safe for biological use. To earn this certification, the silicone must pass a series of tests that evaluate:
Systemic toxicity (whether it causes harmful effects in the body)
Intracutaneous reactivity (whether it causes irritation to tissues)
Implantation tests (how the material behaves when implanted in living tissue)
These tests are typically done on animal models, usually rabbits or mice, and ensure the material won’t cause adverse biological reactions.
Applications for USP Class VI certified silicones include:
Medical tubing
Seals and gaskets in pharmaceutical manufacturing
Short-term implants (less than 29 days)
Food-contact components
The U.S. Pharmacopeia (USP), a non-profit organization, defines the requirements for USP Class VI silicones, including a systemic toxicity test, an intracutaneous test, and an implantation test. These tests are related to the material’s end-use and account for conditions such as patient contact time. Although the USP is not a regulatory agency, its standards inform decision-making at the FDA.
USP Class VI biocompatibility requirements aren’t as stringent as those found in ISO-10993, an international standard for the biological evaluation of medical devices. However, testing medical silicones to ISO-10993 is more time-consuming and costly than is necessary for most non-implantable applications.
SSP2390 medical silicones from Specialty Silicone Products (SSP) meet USP Class VI requirements. Our 10-durometer and 50-durometer products have been certified by the U.S. Pharmacopeia (USP).
SSP2390 also meets the requirements of Restriction of Hazardous Substances (RoHS), a European Union (EU) directive. For medical products that are sold in Europe, USP Class VI silicones can meet the European Union’s Restriction of Hazardous Substances (RoHS) Directive 2002/95/E.
USP Class VI silicones provide the right balance between cost savings and patient protection, but medical manufacturers need to protect themselves against supplier cost-cutting that can invalidate compliance. It’s also important to evaluate all of a material’s attributes, such as color and durometer, and to choose USP Class VI silicones that have passed third-party testing.
Medical manufacturers need to ask their suppliers for certificates, or certs. Make sure you understand the difference between a Certificate of Analysis (COA) and a Certificate of Conformance (COA). COAs report the test results for a specific batch of materials. By contrast, COCs simply attest to a medical silicone’s compliance.
If the formula for a USP Class VI silicone changes, a COC from a supplier’s Quality Department may contain out-of-date or inaccurate information. When you choose medical grade silicones from SSP, you can get a COA with every batch.
Normally, USP Class VI silicones are translucent. However, a compounder can add custom colors to support distinctive medical product designs. What designers need to consider, however, is that the pigments that are used may require additional testing to demonstrate compliance. There could also be compliance-related differences based on the durometer of the material.
The durometer, or hardness, of a USP Class VI silicone is also important since it determines the elastomer’s compressibility, which supports sealing.
The curing system that is used is especially important. Platinum-cured silicones are cleaner than peroxide-cured silicones and produce less off-gassing, the release of fumes or gases that may contain volatile organic compounds (VOCs). Platinum curing also offers greater control over cure rates and cross-linking for silicones that are more consistent in terms of appearance. In addition, platinum-cured silicones also have stronger physical properties and lower shrinkage values.
Finally, it’s important to consider the tolerances, sizes, and lead times of USP Class VI silicones. When sheets are compression molded, they come in standard sizes based on available tooling. Continuous roll technology can produce ten times as many sheets per hour, and with tight tolerances. Importantly, rolls can also be converted to custom sheet sizes. For applications where a medical manufacturer needs a ready-to-mold compound instead, compression molding can be used for parts production.
When manufacturing medical devices or components with silicones, companies must address several critical factors to ensure compliance, safety, and performance. Below is a general overview of considerations for medical manufacturing with silicones.
Important: These guidelines are general information. It is your responsibility to determine materials suitability and compliance with regulatory requirements.
FDA Regulations: Ensure compliance with FDA 21 CFR 177.2600 (for food and drug-safe silicones) or other specific FDA standards for medical-grade materials. For medical devices, follow 21 CFR Part 820 (Quality System Regulation).
ISO Standards: Know the difference between ISO standards.
ISO 10993 is for biocompatibility testing to confirm that silicone is safe for human contact.
ISO 13485 is for quality management systems for manufacturing medical devices.
Class of Medical Device: Understand the device classification (Class I, II, or III) as this determines the regulatory path and testing requirements.
Mechanical Properties: Evaluate properties such as elasticity, tensile strength, and tear resistance based on the intended use (e.g., catheters, implants, gaskets).
Thermal Stability: Ensure the silicone will maintain its performance across a wide temperature range, especially in applications like implants or sterilizable products.
Durability: Assess long-term stability in contact with body fluids, high pressures, or mechanical stresses.
Curing Methods: Choose an appropriate curing method (e.g., platinum cure) to avoid residual by-products that could pose health risks.
Processing Environment: Avoid contamination during molding, extrusion, or assembly.
Tooling and Mold Design: Optimize mold design for silicone’s unique flow and shrinkage characteristics. Use non-reactive coatings on tools to prevent contamination.
Post-Processing: Implement post-curing steps to remove residual volatile compounds and enhance material performance.
Implantable Devices: For short-term implants, ensure compliance with USP Class VI and FDA guidance for implantable materials.
Drug-Delivery Systems: Ensure compatibility with active pharmaceutical ingredients (APIs) and assess leachables/extractables.
Wound Care or Skin Contact: Choose silicone formulations that adhere safely to skin without causing irritation or damage.
Batch-to-Batch Consistency: Implement rigorous quality control to ensure consistency in material properties and performance.
Aging and Shelf Life: Conduct accelerated aging tests to validate the product’s performance over time.
Extractables and Leachables Testing: Test for substances that may migrate from the silicone under use conditions, particularly in high-risk applications.
Waste Management: Ensure proper disposal or recycling of silicone waste to minimize environmental impact.
Energy Efficiency: Optimize manufacturing processes to reduce energy consumption.