As the regulations on PFAS in the United States and Europe become increasingly strict, understanding whether silicone contains PFAS can help you control compliance risks to a certain extent. This article will comprehensively introduce PFAS and the sources of this substance in silicone, helping your products meet market access requirements.
What are PFAS?
Per- and Polyfluoroalkyl Substances (PFAS) are synthetic chemicals that have been widely used in various industries worldwide since the 1940s. You may come across PFAS in various industrial applications such as non-stick pans, waterproof clothing, and fire-fighting foams.
Due to the extremely strong chemical bonds that bind them together, PFAS possess properties such as water resistance, oil resistance, and high temperature resistance. However, many PFAS are highly persistent. Certain PFAS have been associated with bioaccumulation and toxicological concerns and they are difficult to degrade in the environment.
The definitions of PFAS vary among different regulatory systems, and understanding these differences is crucial for the compliance of your product exports:
| Organization / Region | Definition | Scope of Application |
| OECD | Contains at least one fully fluorinated methyl group (-CF₃) or methylene group (-CF₂-) carbon atom | European Union and International General Use |
| US EPA | Features one of the three specific structures: R–(CF₂)–CF(R′)R″, R–CF₂OCF₂–R′, CF₃C(CF₃)R′R″ | U.S. Federal Level |
| Selected U.S. States | Contains at least one fully fluorinated carbon atom | Broad definition |
Health Concerns Related to PFAS
If your product contains a certain concentration of PFAS, prolonged exposure by your customers and workers may lead to adverse health effects, including cancer risks, metabolic and liver toxicity, immune system toxicity, and endocrine disruption.
Therefore, consumers are increasingly concerned about the presence of PFAS in daily products, especially in kitchenware that comes into direct contact with food.
Environmental Impact of PFAS
PFAS also have a significant impact on the environment. Due to the C-F bonds in PFAS, they are almost impossible to degrade under natural conditions. Once they enter the environment, these chemicals will contaminate soil and water sources.
PFAS are transported to remote areas through ocean currents and the atmosphere, thus their effects are global and long-lasting.
Does Pure Silicone Contain PFAS?
If you are using pure silicone without any modification, it is not classified as PFAS. Because the main chain of silicone is composed of Si-O-Si bonds, which do not contain C-F bonds, and C-F bonds are the core structural feature of PFAS.
In the silicone industry, many applications are made of pure silicone rather than modified silicone, such as spatulas, spoons, ordinary sealing rings, baby bottles and nipples, etc. For these pure silicone products, you can claim “PFAS-free” in your promotion and provide a test report to meet the compliance requirements.
According to the definition of the OECD, fluorosilicone rubber (FVMQ) is classified as PFAS because its molecular structure inherently contains fluorine.
3 Sources of PFAS in Silicone
Although the silicone manufacturing industry is not a major user of PFAS, you still need to be vigilant about the presence of PFAS. PFAS may contaminate through by-products or raw materials, accidentally mixed into the production process, and ultimately remain in your silicone finished products.
The following three situations are what you may encounter during the production of silicone products:
PTFE Modified Silicone
If you are familiar with silicone products, you will have some knowledge of PTFE-modified silicone. This is because certain high-performance seals, gaskets and specialty tubing products may incorporate PTFE additives to improve their performance.
It enables silicone to have better low friction, wear resistance, acid and alkali solvent resistance, non-stick property, and low leaching performance.
However, under many regulatory definitions, including the OECD definition, PTFE is considered a PFAS fluoropolymer. If you use PTFE modified silicone to produce your products, you cannot claim “PFAS-free” and must disclose this risk to your customers.
We suggest that before your product enters the markets of the European Union and some states in the United States, it should be carefully examined to ensure compliance with the relevant PFAS regulations.
Alternative Solutions
If your client requires high-performance silicone products but demands PFAS-free, you can reduce the friction coefficient by adding MoS₂ or graphite, use ultra-hard silicone or add silica fillers to enhance wear resistance.
However, the performance of the alternative silicone materials usually cannot be 100% equivalent to PTFE-modified silicone, so it is necessary to inform your customer about this in advance.
Fluorinated Release Agents or Processing Aids
Even if all the raw materials used in your production process are pure silicone, PFAS may still be introduced. Generally speaking, the amount of auxiliary materials used is small, but there is still a residual risk. Here are some of the most common sources:
- Fluorine-containing demolding agent: In the form of spray or liquid, used to assist products in coming off the mold
- Fluorine-containing processing aid: Used to improve the fluidity of the rubber compound and prevent the roller from sticking
- Some release films may use fluorinated surface treatments: The PET films used during vulcanization may have a fluorine coating
Alternative Solutions
When you are in the production process, you can choose non-fluorine-based release agents or release films as alternatives. We suggest that you can use water-based release agents, silicone-based release agents, non-fluorine PET films, and paper-based release paper. These are all PFAS-free and suitable for your use in food and baby products.
Recycled Silicone or Blended Materials
If you incorporate recycled silicone materials in your production for environmental marketing or cost reduction, it may introduce an additional risk of PFAS contamination. The recycled materials may contain waste from FVMQ, PTFE-modified silicone, and other fluorine-containing rubbers such as FKM and FFKM.
To avoid post-sale issues, you must clearly disclose the potential PFAS risk to the customers when selling. We recommend that you conduct pre-tests on each batch of recycled materials.
Regulations on PFAS in Silicone
The regulatory environment for PFAS is constantly evolving, and all industries, including the silicone manufacturing sector, need to ensure product compliance. The following table presents the relevant regulations we have compiled. You can keep an eye on any changes in the regulations.
| Regulation / Authority | Impact on Silicone |
| EU REACH PFAS Restriction Proposal | Restricts all PFAS, including PTFE modified silicone |
| US EPA TSCA 8(a)(7) | Mandates reporting of PFAS imported since 2011 |
| State Laws of Maine, Minnesota, etc. | Declaration required for products containing any fully fluorinated carbon atoms |
| ECHA SVHC List | PFOA, PFOS and other substances are included |
There are various standards for testing whether different products contain PFAS. Before your silicone products are launched onto the market, they usually also need to pass these tests:
- CEN/TS 15968: Commonly used for determining extractable organic fluorine (EOF)
- LC-MS/MS: Quantitative determination of specific PFAS substances
- Total Organic Fluorine (TOF): TOF is typically used as a screening tool and cannot identify individual PFAS compounds.
FAQ
Is FDA-Compliant Food-Grade Silicone Free of PFAS?
It does not automatically mean the same thing. Because the FDA requires higher purity and production control standards for silicone, but not the PFAS testing standards. Even though your silicone products have passed the FDA inspection, they still need to undergo separate PFAS testing to ensure that this risk is avoided.
What Are the PFAS Differences Between LSR and HCR?
There is no fundamental difference between LSR and HCR. Since the chemical structures of these two types of silicone are the same and they are not inherently PFAS-containing materials. The main factor lies in whether you added PTFE modification during the production process or whether you used fluorine-containing additives.
What Are the Regulatory PFAS Limits for Silicone Products?
The regulatory requirements vary significantly across different regions. Many recent PFAS regulations mainly focus on intentionally added PFAS, reporting obligations or specific PFAS substances, and do not set a uniform concentration limit. You should pay attention to the specific requirements of the target market.
How to Avoid PFAS Risks When Purchasing Pure Silicone?
You can request the raw material supplier to provide a PFAS-free declaration and establish a traceable supply chain, ensuring that each batch of silicone raw materials has a batch number, which can be traced back to the original supplier. It is best to regularly test the finished products to minimize the risk of PFAS as much as possible.
How to Identify PTFE Modified Silicone?
Although the wear resistance and non-stick properties of PTFE-modified silicone are improved compared to pure silicone, it is difficult to distinguish them just by looking or touching.
When purchasing, you can pay attention to the fact that the names often contain words like “PTFE”, “Teflon®”, “fluoropolymer”, or the technical parameter tables indicate “PTFE modified” or “with PTFE”, which are usually PTFE-modified silicone.
Final Thoughts
Legensilico, as a professional manufacturer of silicone products, can provide you with various silicone items and ensure their safety. If you have any further questions about PFAS or wish to collaborate with us, please feel free to contact us at any time.
