Silicone is a polymer used widely in consumer goods, from construction sealants to medical devices. As consumers focus on material safety, especially for food preparation and baby care, the purity of these materials is a major concern. Platinum silicone is often considered the superior option. This article explores the science behind platinum-cured silicone to explain why it is considered a safe material for household use.
What Makes Platinum Silicone Different
The distinction of platinum silicone lies in its manufacturing process, known as addition curing. This method uses a platinum compound as a catalyst to initiate the cross-linking of silicone molecules. This process converts the raw material into a solid, resilient rubber. The reaction is highly controlled and does not produce any byproducts, resulting in a purer final product.
This contrasts with the older, more common peroxide-curing method, which uses organic peroxides. Peroxide curing is less expensive but generates volatile organic compounds (VOCs) and organic acid residues as byproducts. Although manufacturers can reduce these residues through post-curing, peroxide-cured silicone is generally not as clean. The absence of these volatile chemical leftovers is the foundation for platinum silicone’s superior purity and safety claims.
High Thermal Stability and Chemical Purity
Platinum-cured silicone is chemically inert, meaning it resists reacting with other substances. This robust structure remains stable across an extremely wide range of temperatures, typically from -55°C to over 200°C. This stability allows it to be used safely for both freezing food and baking at high oven temperatures without degradation.
Leaching refers to the transfer of chemicals from the material into the food or liquid it contacts. Because platinum silicone is a high-purity elastomer without volatile byproducts, it demonstrates extremely low levels of extractables and leachables. This resistance ensures the silicone does not transfer odors, flavors, or harmful substances into food, even after repeated exposure to heat or steam sterilization.
Testing and Regulatory Standards
The safety of silicone products is externally validated by rigorous testing standards around the world. The U.S. Food and Drug Administration (FDA) requires that food-grade silicone meet specific criteria. This ensures the material is non-toxic and safe for food contact, involving tests for potential chemical transfer to food.
The German LFGB standard is another highly regarded benchmark often met by premium platinum silicone products. The LFGB standard is considered stricter than the FDA’s requirements, especially regarding testing for volatile compounds and sensory transfer, such as odor or taste. Products achieving LFGB certification must demonstrate exceptional purity, often requiring the cleaner platinum-curing process to pass comprehensive tests.
Identifying Quality and Avoiding Counterfeits
Consumers have practical ways to assess the quality of silicone before relying on it for food contact. A common technique is the “pinch test,” which helps identify the presence of cheap fillers often used in lower-grade silicone. To perform the test, firmly pinch or twist a section of the silicone item.
If the pinched area turns white, it indicates the presence of fillers, such as precipitated silica. These are cheaper alternatives to the high-purity fumed silica used in the best platinum silicone. High-quality, pure platinum-cured silicone should not change color when stressed, maintaining its original color. Consumers should also look for clear labeling confirming compliance with LFGB or FDA standards and choose products from transparent manufacturers.