Halogen-free and fluorine-free flame retardants: How halogens, PTFE and PFAS relate

Why customers have started to ask for "halogen-free" and "fluorine-free"

Many electronics and appliance brands have added two requirements to their material specifications:

• Flame-retardant materials contain no brominated or chlorinated flame retardants (halogen-free);
• Materials contain no PFAS, including fluoropolymers such as PTFE (fluorine-free).

The first has been in place for many years. The second is a newer requirement that has appeared in recent years with the EU discussion on restricting PFAS.

Halogenated flame retardants and halogen-free flame retardancy

Brominated flame retardants are efficient and low cost, and were once widely used. But some of them are now restricted by regulation, such as the polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE) restricted by RoHS. Halogenated materials also give off corrosive smoke when they burn. So many brands have chosen to stop using halogenated flame retardants altogether.

Common approaches to halogen-free flame retardancy:

• Phosphorus-based flame retardants

  Common in PC and PC/ABS, fairly efficient, may affect heat resistance and flow.

• Silicone-based flame retardants

  Used in PC systems, with less effect on impact and heat resistance, but a narrower range of use.

• Others

  Nitrogen-based systems, inorganic fillers and so on, mostly used in other material systems.

Common ways to define "halogen-free"

"Halogen-free" usually refers to the limits in IEC 61249-2-21:

Testing usually uses combustion ion chromatography, such as EN 14582. Note: this limit does not include fluorine, so a "halogen-free" material may still contain PTFE.

Some brands have their own stricter limits. Follow your material specification.

The role of PTFE in flame-retardant formulations

In vertical burning, molten plastic drips. If the drips ignite the cotton below, the material cannot reach V-0 or V-1.

A small amount of PTFE (polytetrafluoroethylene) added to a flame-retardant formulation forms a fiber network during processing. When the material burns, this network holds up the melt and reduces dripping. That is why PTFE is often called an "anti-drip agent".

The PTFE loading is very small, usually below 1 % (typical value). But it is a fluoropolymer and falls within the definition of PFAS.

Progress on PFAS restrictions

PFAS (per- and polyfluoroalkyl substances) are a large class of fluorinated compounds that are very hard to break down. In January 2023, the authorities of five countries (Denmark, Germany, the Netherlands, Norway and Sweden) submitted a restriction proposal to the European Chemicals Agency (ECHA) covering almost all PFAS, including fluoropolymers.

Current status: a proposal, still under review, not yet adopted. (As of October 2026)

• In August 2025, the dossier submitters published an updated proposal.
• In March 2026, ECHA's Committee for Risk Assessment (RAC) adopted its final opinion, and the Committee for Socio-economic Analysis (SEAC) agreed its draft opinion. Both committees support an EU-wide restriction on PFAS, with derogations for some uses.
• The public consultation on the SEAC draft opinion closed in May 2026. SEAC plans to discuss and adopt its final opinion at its November 2026 meeting.
• ECHA will then send both opinions to the European Commission. The Commission will propose a restriction, which the REACH Committee of member state representatives then votes on.

The final scope, derogations and transition periods are not yet set. Even so, many export brands already require "PFAS-free" in their material specifications.

(Regulations change. The information in this article is as of October 2026.)

Trade-offs of fluorine-free flame retardancy

Without PTFE, dripping has to be controlled in other ways. Common methods:

• Choose a flame-retardant system with better char formation, such as silicone-based flame-retardant PC;
• Adjust the melt strength and viscosity of the base resin;
• Optimize the combination of flame retardants and additives.

Trade-offs:

• Wall thickness

  Reaching V-0 in thin walls is harder; walls may need to be thicker

• Flow

  Raising melt strength to control dripping may lower flow

• Cost

  Some fluorine-free systems have higher raw material costs

• Validation

  Flammability and reliability must be validated again

How to confirm with your material supplier

• Ask the supplier whether halogenated flame retardants are used, and for a halogen test report.
• Ask the supplier whether PTFE or other fluorinated substances are intentionally added to the formulation.
• If needed, ask for a test report on total fluorine or fluorinated substances.
• Confirm the grade, color and date that the test report covers.
• Require the supplier to notify you in advance of formulation changes.

References

1. IEC 61249-2-21:2003International Electrotechnical Commission (IEC) · 2003
2. Halogen-free board (JEDEC dictionary)JEDEC
3. ECHA publishes updated PFAS restriction proposalEuropean Chemicals Agency (ECHA) · 2025-08-20
4. ECHA supports PFAS restriction with targeted derogationsEuropean Chemicals Agency (ECHA) · 2026-03-26
5. Q&A on the PFAS restriction processEuropean Chemicals Agency (ECHA)
6. Q&A on ECHA's PFAS opinionsEuropean Chemicals Agency (ECHA)
7. SEAC work planEuropean Chemicals Agency (ECHA)
8. Europe's PFAS restriction proposal moving forwardWhite & Case

Accessed 2026-10-19.