PFAS Facts & Frequently Asked Questions (FAQs)

What is PFAS?

PFAS is a term referring to perfluoroalkyl and polyfluoroalkyl substances, which encompasses over 10,000 different chemicals that are widely used across key industries, from chemical processing, to pharmaceutical, to semiconductor. As defined under Europe’s REACH framework, any substances with a -CF2 group or -CF3 group in its chemical structure are categorized as PFAS.

 

 

Why is there a push to regulate PFAS?

Past regulations largely focused on non-polymeric types of PFAS. Some sub-groups of PFAS, such as PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate) have been regulated by the United States EPA, due to their accumulation in drinking water posing environmental and toxicological risks. Current regulatory efforts target a much broader range of PFAS, including fluoropolymers and the process aids and byproducts associated with their production. This would significantly impact critical industries such as semiconductors, where fluoropolymers are widely used in sealing materials due to their unique properties and unmatched performance. Ongoing research into the specific types of PFAS, and their associated effects, by organizations such as the United States EPA is essential to promoting effective, science-based regulations.

 

 

Do FKM (fluoroelastomer) and FFKM (perfluoroelastomer) contain PFAS?

Yes. Fluoropolymers are a sub-group of PFAS. All FKM/FFKM have a chemical structure composed of PFAS. Unlike PFOA or PFOS, the long fluoropolymer chains that make up FKM/FFKM are categorized as a Polymer of Low Concern (PLC) by organizations such as OECD (Organization for Economic Co-Operation and Development), distinguishing it as having insignificant environmental and human toxicological impact. This PLC status was based on the high molecular weight and overall chemical inertness of the fluoropolymer chains, which corresponds to greatly reduced ability to permeate biological membranes versus the types of PFAS that were determined to be harmful.

 

 

Why are perfluoroelastomers vital for semiconductor fabrication?

Seals are used throughout the fab and sub-fab - in load locks and transfer modules, in and around the process chambers, in gas delivery systems, in various control valves, heated forelines, pumps, exhaust lines, and abatement systems. The most critical semiconductor fabrication processes require a high-performance sealing material which:

1. Maintains sealing contact with long-term resilience, such as for vacuum or pressurized fluid environments.

2. Does not introduce unwanted ions or organic contaminants that can interfere with or damage transistor maps or other highly sensitive components.

3. Can withstand harsh, corrosive chemicals, such as plasmas, which are essential to key fabrication processes.

 

Perfluoroelastomers are the most prominent sealing materials preferred by the semiconductor industry’s fabs and equipment manufacturers, due to their unmatched combination of physical resilience, chemical compatibility, thermal resistance, and purity. Few, if any, viable alternatives exist if perfluoroelastomers can no longer be used.

 

 

What is the impact of 3M’s cessation of FFKM manufacturing to ASNA’s supply chain and products?

ASNA does not currently manufacture or sell any products containing 3M-based fluoropolymers.

 

 

What actions are being taken currently by ASNA to be compliant with the proposed PFAS regulation if it comes into effect?

ASNA is a member of SEMI-sponsored consortiums that are proactively discussing PFAS regulations, use, and sustainability.

 

ASNA is working closely with its fluoropolymer suppliers to comply with the proposed regulations and implement sustainable solutions.  The manufacturing process of FKM/FFKM often requires fluorinated process aids, such as fluorosurfactants, and sometimes includes the creation of PFAS-containing byproducts.

 

Chemical makers responsible for the production of FKM/FFKM are currently researching and implementing ways to eliminate the use of fluorinated process aids, thus ensuring the sustainability and continued viability of FKM/FFKM products for critical industries.

 

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