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FDA Grade Translucent Silicone

FDA grade translucent solid silicone sheet from ElastaPro is designed for food contact applications. This FDA compliant silicone rubber meets the requirements of CFR 177.2600 and, like white silicone FDA sheeting, is used in food grade silicone rubber gaskets. Translucent silicone rubber isn’t the same as clear silicone sheet, but it let’s light pass through instead.

30 to 70 Durometer FDA Grade Translucent Silicone

Translucent FDA solid silicone sheets are available from 30 to 70 durometer.

Food Grade Solid Silicone Sheeting

This FDA silicone rubber from ElastaPro provides a superior sealing solution. Solid FDA silicone sheet in translucent silicone rubber also provides a clean appearance.

This table lists properties and test method for specific products.

Translucent FDA Grade Silicone

FDA Grade Translucent Silicones: Properties, Standards, and Applications

Silicone elastomers are indispensable materials in industries where biocompatibility, chemical resistance, and thermal stability are critical. Among their many formulations, FDA-grade translucent silicones stand out as a class of materials that comply with the U.S. Food and Drug Administration’s regulatory framework for use in food contact and medical environments.

These silicones combine the performance advantages of the polysiloxane backbone with regulatory assurance, offering engineers a material solution that is both functionally robust and compliant with safety requirements. This paper provides a technical overview of FDA-grade translucent silicones, discussing their chemical structure, material properties, applicable standards, processing considerations, and real-world engineering applications.

Regulatory Basis for FDA Grade Silicones

The FDA regulates polymers intended for food contact under 21 CFR §177.2600 – Rubber Articles Intended for Repeated Use. For silicone elastomers to qualify as FDA-grade:

  • They must be compounded from ingredients recognized as safe for direct or indirect food contact.
  • They must not leach harmful extractables into food or beverages under prescribed conditions.
  • They must withstand repeated exposure to aqueous, acidic, and fatty food simulants without exceeding specified extraction limits.

In addition to FDA criteria, many manufacturers also test their materials against USP Class VI (for medical biocompatibility), ISO 10993 (for biological evaluation), and NSF 51/61 standards for food and potable water contact.

Molecular Architecture of Translucent Silicones

Silicones are based on the repeating siloxane backbone (–Si–O–Si–) with organic substituents, typically methyl or vinyl groups. The siloxane bond is longer and more flexible than a carbon–carbon bond, providing high chain mobility and low glass transition temperature (~–127 °C).

Translucency

Unlike opaque silicone formulations that contain pigments or high filler loadings, translucent silicones are formulated with:

  • Optimized fumed silica reinforcement – particle sizes <20 nm, well dispersed to enhance mechanical strength without excessive light scattering.
  • Minimal colorant or opacity additives – resulting in high light transmission (often >70% in thin sections).
  • Careful vulcanization chemistry – usually platinum-catalyzed addition curing to avoid peroxide residues that could compromise clarity or FDA compliance.

The result is a material with semi-transparent appearance, useful for applications where visual inspection, aesthetics, or light diffusion are important.

Mechanical Properties of Translucent Silicones FDA Grade

FDA-grade translucent silicones offer a well-balanced mechanical profile:

  • Hardness (Shore A): Typically 30–80, covering soft, flexible seals up to firm structural gaskets.
  • Tensile Strength: 7–12 MPa, depending on formulation and filler content.
  • Elongation at Break: 300–600%, ensuring resilience under strain.
  • Tear Strength: 25–40 kN/m, sufficient for food-grade seals and tubing subject to repeated flexing.
  • Compression Set: <25% after 22 h at 175 °C, maintaining sealing performance over repeated use.

Compared to general-purpose silicones, FDA-grade translucent grades are optimized for low extractables while maintaining high tear resistance and durability.

Thermal and Environmental Resistance of Translucent Silicones FDA Grade

Operating Range

Silicone elastomers are distinguished by their wide service temperature window:

  • Continuous service: –60 °C to +200 °C
  • Intermittent peaks: up to 230–250 °C

This allows FDA-grade translucent silicones to survive sterilization processes such as steam autoclaving, gamma irradiation, and ethylene oxide (EtO) exposure, making them suitable for reusable medical devices.

Weathering and UV Resistance

The Si–O bond provides inherent resistance to:

  • Ozone cracking
  • Ultraviolet degradation
  • Hydrolytic attack

These features ensure long service life in outdoor food processing or medical transport environments.

Chemical Resistance and Extractables of FDA Grade Translucent Silicones

FDA-grade translucent silicones are engineered to resist:

  • Aqueous solutions (neutral or slightly acidic/basic)
  • Dilute detergents and cleaning agents
  • Fats and oils (with limited swelling)

They remain stable in most food simulants. However, like all silicones, they are susceptible to swelling in nonpolar hydrocarbons (e.g., hexane, gasoline) and strong solvents.

The defining feature of FDA-grade formulations is low extractables. During FDA testing, samples are immersed in distilled water, n-heptane, and 8% ethanol under reflux conditions. The weight of extracted matter must fall below regulatory thresholds. Achieving this requires:

  • High-purity fillers
  • Platinum curing (instead of peroxides, which leave residues)
  • Careful raw material selection to eliminate unreacted oligomers

Electrical and Optical Properties

Although electrical insulation is not always the primary selection factor in FDA-grade silicones, their dielectric profile is attractive:

  • Dielectric Strength: 20–25 kV/mm
  • Dielectric Constant: ~2.9–3.2 (stable across frequency)
  • Dissipation Factor: <0.003

Translucency also brings value in optical or inspection applications:

  • Light transmission enables visual monitoring of fluid flow in tubing.
  • Diffusion properties are useful in illumination covers or medical diagnostic equipment.

Processing and Fabrication

FDA-grade translucent silicones are available in several forms:

  • High Consistency Rubber (HCR) – suited for extrusion into tubing and profiles or compression molding into seals.
  • Liquid Silicone Rubber (LSR) – two-part platinum-cured systems with low viscosity, injection-moldable for precision medical and food-grade components.
  • Sheet Goods and Rolls – calendered solid silicone sheets for die-cut gaskets.

Post-curing is often required (4–8 hours at 200 °C) to reduce volatiles, optimize crosslink density, and meet FDA extraction criteria.

Secondary processes such as die-cutting, water-jet cutting, or adhesive bonding are compatible, provided FDA-approved adhesives are selected.

Standards and Testing

Engineers specifying FDA-grade translucent silicones must be aware of multiple standards:

  • 21 CFR §177.2600 – FDA compliance for food contact
  • USP Class VI – systemic toxicity, intracutaneous reactivity, and implantation testing
  • ISO 10993 – biological evaluation of medical devices
  • NSF 51/61 – food equipment and drinking water system components
  • ASTM D2000 – standard classification for rubber products

Testing encompasses tensile and tear strength (ASTM D412, D624), compression set (ASTM D395), and extractables (per CFR 177.2600 protocols).

Applications

Food and Beverage Processing

  • Sanitary gaskets for pumps, tanks, and filling equipment
  • Tubing for beverage transfer and dairy handling
  • Oven door seals and bakeware components requiring heat resistance

Medical and Pharmaceutical

  • Peristaltic pump tubing with clarity for fluid monitoring
  • Respiratory masks and connectors with patient contact
  • Seals in diagnostic instruments requiring sterilization compatibility

General Industrial

  • Electrical insulation in environments requiring FDA compliance
  • Transparent seals where visual inspection is required
  • Flexible membranes in pharmaceutical packaging

Engineering Considerations in Material Selection

When specifying FDA-grade translucent silicone, engineers must evaluate:

  1. Operating Environment – continuous vs intermittent heat, sterilization cycles, exposure to oils or solvents.
  2. Mechanical Stress – required tear resistance, elongation, and compression set for seals under load.
  3. Transparency Needs – full clarity versus semi-translucence, depending on optical application.
  4. Regulatory Overlap – whether FDA alone is sufficient or whether USP Class VI/ISO 10993 compliance is also required.
  5. Processing Method – extrusion vs injection molding, and whether LSR or HCR is more economical for the part geometry.

Ask ElastaPro for FDA Grade Translucent Silicones

FDA-grade translucent silicones combine the hallmark performance characteristics of silicone elastomers—thermal stability, flexibility, weathering resistance, and dielectric strength—with regulatory assurance for food, beverage, and medical use. Their unique translucency not only provides aesthetic and inspection advantages but also reflects a high level of formulation purity. By meeting FDA 21 CFR §177.2600 standards and often overlapping with USP Class VI and ISO 10993 biocompatibility, these materials offer engineers a versatile and reliable choice for safety-critical applications. From sanitary gaskets and food transfer tubing to medical masks and diagnostic devices, FDA-grade translucent silicones deliver both compliance and performance in environments where no compromise is acceptable.

Do you need FDA grade translucent silicones? Contact ElastaPro.