PFAS - Relevance for UV sensors, UV systems and UV measurement technology

Per- and polyfluoroalkyl substances (PFAS) refer to a very large group of substances with exceptional thermal and chemical stability. However, their longevity, wide environmental distribution and toxicological findings for individual representatives justify regulatory measures. In UV technology, PFAS particularly affect fluorinated polymers, especially PTFE (polytetrafluoroethylene) in diffusers and ageing-resistant cable materials/shielding. 

Regulatory overview

The European Union is pursuing a group-wide REACH restriction proposal for PFAS. ECHA has published an updated version of this in 2025; the scientific evaluation by RAC/SEAC is to be completed by the end of 2026 (see REACH, Potential PFAS regulation by 2027 - inclusion in Annex XVII). Individual restrictions already exist in parallel.

In the USA, the EPA finalized the first nationally binding limits for six PFAS in drinking water (NPDWR) on April 10, 2024.

In addition, TSCA Section 8(a)(7) is an EPA regulation that requires manufacturers and importers to report historical data on per- and polyfluoroalkyl substances (PFAS) manufactured since 2011.

Unlike PFAS substances, PTFE remains stable as a macromolecular structure and does not degrade or release under normal conditions. The EPA recognizes these differences, but intentionally waives exemptions in the 8(a)(7) rule in order to create a complete data base over the entire PFAS life cycle. The aim is a comprehensive inventory, not an immediate restriction or ban. For systems containing PTFE, this means additional administrative work (notification, documentation, supply chain transparency), but no restriction on use or marketing.

PTFE in the PFAS context

Polytetrafluoroethylene (PTFE) is a fluoropolymer. In scientific reviews, fluoropolymers including PTFE often meet recognized criteria for "polymers of low concern" (PLC). The PTFE CAS# / the LVE case is DTXSID7047724.

This classification is based on the macromolecular structure and high chemical stability of the material. Due to its polymeric bonding architecture, PTFE has no relevant water solubility, no bioavailability and no bioaccumulation.

The carbon-fluorine bond in the polymer backbone is extremely low in energy, which rules out the release of monomers or reactive fluorine compounds under normal operating conditions.

The OECD has described the "polymers of low concern" concept since 2009; however, there is no formal, globally standardized recognition of individual polymers by the OECD and national criteria vary.

Various OECD and EU expert committees therefore recognize that fluoropolymers such as PTFE do not generally fall into the same risk category as low molecular weight PFAS due to their inertness and lack of environmental mobility. Nevertheless, the assessment within the framework of European PFAS regulation remains open, as PFAS precursors or processing aids may potentially be involved in production and disposal.

Industrial use of PFAS and PTFE in UV sensor technology

PFAS in optical diffusers

PTFE-based diffusers/reflective materials offer high, almost Lambertian reflection and UV suitability up to the UVC range. Alternatively, quartz glass diffusers are available. 

Cables and shielding

PFAS-based materials are used in high-energy UV environments due to their temperature and material resistance, among other things. With high-temperature-resistant polymers (e.g. PEEK for defined temperature windows), silicone/fluorosilicone mixtures, metallic braids with UV-stable jacket materials; replacement products already exist.

 

PTFE in integrating spheres

Integrating spheres are used for the homogeneous distribution and integration of optical radiation. They are used to measure radiance, spectral irradiance, reflection, transmission or light output of sources. The decisive factor is the most isotropic, Lambertian reflection possible in the relevant spectral range.

PTFE (polytetrafluoroethylene) and alternatively BaSO₄ (barium sulphate) are the dominant materials for integrating spheres in UV and VIS measurement technology.

BaSO₄ is used as a reflective layer in integrating spheres, especially in the visible spectrum. In comparison, BaSO₄ has lower stability and durability and limited UV performance. Therefore, the effort for calibration and maintenance may be higher. BaSO₄ offers an established, PFAS-free option for visible and near IR ranges, but has limited substitutability in short-wave UV measurement technology

Current use of materials at Opsytec

In Opsytec's UV sensor technology, PTFE content is typically limited to optical diffusers and selected cable components/shields.

Substitute materials are available. The UV sensor lines RMD, PLC, PLC.d, XT, FLT remain fully available and will be continued without restrictions. Only the design of the RM-12 sensors will be changed from 2027. Here is an overview of the relevant products:

* PFAS-ready: Can be converted without restrictions
* PFAS-free: Contains no PFAS (especially PTFE)

Neither early announcements nor blanket product restrictions or delivery limitations are planned.

Opsytec's long-term supply capability is assured as it relies on proven supply chains, qualified materials and forward-looking production management.

At the same time, regulatory developments - particularly in the area of PFAS regulation - are continuously monitored, evaluated and, if necessary, integrated into internal product change management in a structured manner.

This ensures product continuity, while technological developments and legal requirements can be incorporated into future generations of UV sensors at an early stage and in a controlled manner.

To summarize:

No early discontinuations, no restrictions on existing UV sensor lines.

We will be able to replace PTFE as early as 2025.

Our goal is to develop PFAS-free products by 2027, wherever this is technically possible.

Note: 

Statements on Opsytec's product policy (continuity without discontinuations/restrictions) refer to the current internal planning status. Changes to external regulations are continuously evaluated and implemented as required. Opsytec reserves the right to select cables.

Last update 10/16/2025