Document YDMLv71Y8JjX0VewmkB8veZjK

covThestro This document is non-confidential 1/35 covestro.com 13th of July 2023 Covestro Deutschland AG's non-confidential input to the Public Consultation on the dossier for restrictions on per- and polyfluoroalkyl substances (PFAS) General Remarks: Covestro is one of the top three producers of isocyanates, polycarbonates, chlorine, caustic soda and hydrochloric acid in the chemical sector, employing globally ~18,000 people. These products are used in a wide range of applications, e.g., sustainable buildings, efficient cooling units, future mobility, sustainable energy, lifesaving medical devices, corrosion-protective coatings, pulp and paper, detergents, packaging, agriculture, environmental protection, water treatment, foodstuff, textiles, and production of batteries. In the following, we provide non-confidential information on Covestro's uses of PFAS substances. 2/35 covestro.com covThestro CHAPTER I Fluoropolymer materials 3/35 covestro.com Table of content 1. Relevance of fluoropolymer material in chemical plants and infrastructure ........................................................................................ 5 1.1 Gaskets and sealings ....................................................................... 6 1.2 Pipes / Pipe supports / Equipment in-liner material / bellows ....... 9 1.3 Pumps, fans, and compressors ..................................................... 12 1.4 Cooling conveyer............................................................................ 13 1.5 Feeder.............................................................................................. 13 1.6 Devices for process control and process analysis, controls, and instruments .................................................................................... 13 1.7 Valves and accessories, fittings, flaps.......................................... 14 1.8 Filtering candle / multiple tube filter.............................................. 15 1.9 Hoses............................................................................................... 16 1.10 Columns, packings, (chlorine) absorption.................................... 16 2. Production of nitroaromatics as precursor for isocyanate production ...................................................................................... 18 3. Fluoropolymers in Chlorine Manufacturing...................................... 20 3.1 Membranes in Chlor-Alkali Electrolysis ........................................ 20 3.2 Diaphragms in Hydrochloric Acid Electrolysis............................. 22 3.3 Gas diffusion electrodes in Chlor-Alkali / Hydrochloric Acid Electrolysis..................................................................................... 23 3.3.1 NaCl-ODC electrolysis.................................................................... 23 3.3.2 HCl-ODC electrolysis...................................................................... 24 4. Emission ............................................................................................. 25 5. Waste Management ............................................................................ 25 6. Pathway for the potential replacement of fluoropolymers .............. 25 7. Annexes .............................................................................................. 27 7.1 Abbreviations ................................................................................. 27 4/35 covestro.com 1. Relevance of fluoropolymer material in chemical plants and infrastructure Chemical plants and associated infrastructure, such as equipment, pipes and sealings, are exposed to harsh conditions. In the past, for example, a lot of equipment and piping systems e.g., in chlor-alkali electrolysis were constructed from carbon steel with rubber lining to ensure corrosion resistance and many sealings were made of asbestos (which has been banned in the EU decades ago). Nevertheless, rubber linings suffer in several applications from corrosion attack resulting in limited lifetime of only several years. Remnants of this infrastructure can still be found in single places but in the chemical industry such materials have been almost completely replaced by modern materials in recent decades. The vast majority of replacements have been made by plastic materials. Depending on their application they provide chemical stability, enable purity of the products and come with a long lifetime as well as with competitive costs. In special cases, nonchemical criteria like electrical isolation in electrolysis cell-rooms have also been considered. Especially the chlorine production and handling in downstream assets includes many unit operations with very harsh chemical conditions, e.g., handling of acid or caustic, brine with high salt concentrations, wet or dry chlorine, etc. A critical point is that the requirements on chemical stability in one process step often undergo drastic changes so that a material which might be suitable at the inlet is not resistant anymore during processing or at the outlet. Fluoropolymers like e.g., PTFE, M-PTFE, ECTFE, PVDF, PFA, FEP, FKM and FPM have proven to be suitable for multiple changing conditions and thus are of utmost importance to ensure corrosion resistance, leak-tightness and lifetime of the chemical plants as well as human and environmental protection. Those materials were a key puzzle piece for continuous improvement of safety and functionality in chemical plants. They have a unique combination of properties (see also Figure 1: Overview of material properties): Inertness and non-reactivity; high resistance to corrosion and chemical attack Low and high temperature resistance: with a range as large as -263C to +260C for PTFE Very low coefficient of friction to any solid Low and ultra-low permeation rates Ultraviolet radiation (UV) resistance Excellent electrical insulation, low dielectric constant, low variations of conductivity High level of fire safety; no flame propagation and low smoke generation High and ultra-high purity with extremely low leach out properties Stress-crack and cut-through resistance Flex fatigue properties enabling thermal expansion/contraction in temperature cycles Biocompatibility High flex-life Durability Hydrophobicity; neither water nor water-containing substances wet fluoropolymers, providing excellent repellent properties to many chemicals Non-stick, and consequently non-fouling properties, along with sufficient bonding in certain multilayer applications 5/35 covestro.com Figure 1: Overview of material properties As described, fluoropolymers are used in many construction materials and production devices. A first draft review is provided and clustered as below: Gaskets and sealings (1.1) Pipes / Pipe supports / Equipments inliner material / bellows (1.2) Pumps, fans, and compressors (1.3) Cooling conveyers (1.4) Feeder (1.5) Devices for process control and process analysis, controls, and instruments (1.6) Valves and accessories, fittings, flaps (1.7) Filtering candle/multiple tube filter (1.8) Hoses (1.9) Columns, packings, absorption (in chlorine services) (1.10) 1.1 Gaskets and sealings A large portion of Flange Gaskets, Packings, Elastomeric & Polymeric Seals and Mechanical Seals used in our plants are made of fluoropolymers or contain fluoropolymers. Fluoropolymers play an important role in the chemical industry, they contribute to safety and sustainability and because of their persistency they must be 6/35 covestro.com replaced very seldom. The chemical industry is relying on sealings made of fluoropolymers due to their unique properties, the most important point for chemical plants is their stability and durability. In this chapter we've listed some uses as example, where fluoropolymer sealings are needed: As Flange gasket (Fig. 3) they are mainly used at flange connections (Fig. 2) where low Sealing pressures and or high chemical resistance are needed (e.g., metal, plastic, glass lined piping). Figure 2: Flange connection with gasket Figure 3: Flange gasket, WN 1000-1045 An additional example is the use of spiral gaskets with fluoropolymer like PTFE layers (Fig. 4) for high pressure applications and to avoid crevice corrosion at the metallic flanges: Figure 4: Flange connection with spiral gasket, gasket is a metal spiral with fluoropolymer like PTFE layers in between The sealing arrangements have been developed over years and be proven to be the best option to avoid leaks and to minimise flange emissions. The Envelope gasket (figure 5) is in many cases used to provide the corrosion resistance to the supporting centre material of the gasket ring, an application is often in glass lined piping. 7/35 covestro.com Figure 5: Envelope gasket with fluoropolymer like PTFE envelope Another gasket consists of PTFE with a corrugated core layer (figure 6) used to provide increased sealing performance e.g., at metal flanges. In most of the cases the layer is made of graphite, but in applications with corrosive substances fluoropolymers are required as PTFE. Figure 6: Corrugated gasket with fluoropolymeric layers Alternatively, the gaskets are also used as a combination for e.g., special application like Jacketed piping with double flange surfaces for surveillance of the inner flange Another application are shaft sealings of most of our mechanical or automatic valves used in the production process (Fig. 7). All valves have a sealing at their shaft. To fulfil the legally binding "TA Luft" according to German law ("Bundesimmissionsschutzgesetz"), which requests that air protection requirements must be resistant under even severe service conditions (chemical attack / temperature), most sealings contain fluoropolymer components as only available reliable and safe option. Figure 7: Ball valve with fluoropolymer packing and internal seal material 8/35 covestro.com Another application is the pressurized shaft sealings of rotating equipment e.g., pumps, dynamic mixers, agitators, extruders, or blowers. There are mostly mechanical seals with o--rings made of fluorelastomers like e.g., FKM in use as only option for the dynamic and static sealing inside the seals (Fig. 8). Figure 8: Double mechanical tandem seal with o-rings made of fluoropolymer Fluorelastomers or components and fluoropolymers are also used in simple applications to seal, reduce friction, and increase the reliability of compression packings in stuffing boxes (figure 9). Figure 9: Stuffing box with packing rings In earlier years asbestos was mainly used as sealing material for flat gaskets or packing materials. Because of the ban of asbestos and potential hazard to life and environment it was mainly replaced by fluoropolymer components as only available alternatives with better or similar performance in the different applications. The mechanical seals had been used reliable in our chemical applications after Fluoropolymer o-rings had been available to resist the complex requirements. When the sealings must be replaced, devices are dismantled and end-of-life material is cleaned, shredded and incinerated under strictly controlled conditions. 1.2 Pipes / Pipe supports / Equipment in-liner material / bellows Flange materials are supporting materials for piping. Flanges made from perfluorocarbons (PFCK) have major advantages that make them indispensable for certain applications. These include: 1. Chemical resistance: PFCK materials are highly resistant to chemicals and can be used in aggressive environments where other materials would fail quickly. 2. Good mechanical properties: PFCK materials are very rigid and have high tensile strength, which makes them suitable for applications where high loads may occur. 9/35 covestro.com 3. Temperature resistance: PFCK materials can withstand high temperatures, making them suitable for applications in high temperature environments. Sliding Plates1 for pipe supports: PTFE (polytetrafluoroethylene) sliding plates are often used as brackets because they have high chemical resistance, very low friction and good temperature resistance. PTFE is a thermoplastic polymer also known under the brand name Teflon. It is known for its excellent non-sticky properties and is often used in applications that require high chemical resistance and low friction. PTFE sliding plates are used as brackets to hold components in one position or to allow movement between components. They are used in a variety of applications. Due to their chemical resistance, PTFE sliding plates are also used in corrosive environments without being affected by exposure to chemicals. Due to their low friction, they can also help reduce wear and energy losses. Pipes, flanges and fittings: Fluoropolymers like PTFE/PVC/PFA/PVDF are used as inliners for piping solutions for high corrosive fluids. Those fluids are hydrochloric acid, sulfuric acid, hydrogen chloride and compressed chlorine gas. There is a limitation in the selection of the type for the lined plastic material due to high operating temperatures up to 180C and operating pressure up to 10 bars. Metallic piping solutions are unsuitable for those fluids because of pitting corrosion and failure of components within a short time of service. Figures 10 and 11 show the kinds of pipes where fluoropolymers are used for fiber-reinforced plastic pipes (see fig. 10) and lined carbon steel pipes (see fig. 11). Figure 10: Lined fiber-reinforced plastic pipes Figure 11: Lined carbon steel pipes As already described fluoropolymers have a unique combination of properties needed for apparatuses and other installations in chemical production. They are essential in terms of safety and reliability, the combination of chemical resistance and high allowable temperatures cannot be met by alternative material available on 1 Slide plate - Wikipedia 10/35 covestro.com the market, e.g., polyolefins, PVC or thermosetting plastics. In some individual cases, alternative materials may exist at the expense of lifetime, durability and safety, but this would need to be analyzed in detail and tested in the laboratory and later in the actual service during production with required precaution. In chlorine production, the aspect of electrical safety must also be considered. Technical measures must be taken to ensure that possible electrical charge within the pipelines is discharged in a safe way, so that, for example, potential hazards to health or environment by sudden spark discharge are excluded. Inliner made from fluoropolymers ensure this requirement. FRP (fiber-reinforced plastic) and steel pipes with in-liner made of fluoropolymers and electrically conductive fluoropolymers are used in the following service (kind of stream, properties) 2: exhaust air, waste gas, wastewater, condensate o acidly o contains solvents o contains chlorine and/or hydrochloric acid o contains phosgene In these applications a limited substitutability is given: In some cases, nonmetallic materials like acid-resistant ceramic linings could be possible; however, smaller diameters cannot be realized and the vacuum resistance that is often necessary is not given. Chlorous gases or fluids o chlorine gas (moist) o sodium hypochlorite (bleaching liquor) o Liquid media in chlorine production with dissolved chlorine: anolyte/catholyte in HCl electrolysis, sulfuric acid in chlorine drying In these applications a limited substitutability is given: glass fiber composites with chemical protection layer or PVC-C, titanium, tantalum and Hastelloy are alternatives in place, but their usage is limited to the actual application due to safety aspects, high voltage needed for chlorine production, also electro corrosion could occur. Oxygen-containing substances for chlorine production o catholyte within HCl-ODC-electrolysis3 (hydrochlorid acid with amounts of solved O2) o catholyte within NaCl-ODC-electrolysis (NaOH, up to 32%, with amounts of solved O2) o process gas from HCl oxidation (HCl, Chlorine, O2) For those substances / processes alternatives are not available. For NaClODC- electrolysis a new type of pipe materials is under evaluation but not yet confirmed for implementation. Chlorinated hydrocarbon Hydrogen chloride 2 Medienlisten 40 DIBt 2022 (dibt.de) 3 ODC: oxygen depolarized cathode, see chapter 4 11/35 covestro.com  Solvents that contain phosgene, phosgene In these applications substitutability R&D would be required to identify alternatives. Hydrochloric acid 37% with a temperature above 60C For hydrochloric acid at these temperatures no alternative materials are available. Sulfuric acid of 78% Alternative material is PVC-C but limited to temperatures up to 60C. Sulfuric acid saturated with chlorine Alternative material is PVC-C (which is also under an EU REACH restriction process) but limited to temperatures up to 80C, in some applications Alloy C-276 is also possible. 1.3 Pumps, fans, and compressors In pumps and other rotating equipment in particular, the requirements on the materials are becoming more stringent, since in addition to the chemical stresses, the materials are exposed to mechanical stress, too. The criteria for a suitable material selection are challenging: Strong mechanical properties Resistance to aggressive chemicals Resistance to low and high temperatures Use in a wide temperature range (between -60C and +200C) Small abrasion (unavoidable loss of wall thickness per year) Long ago, chromium/nickel alloys were used for such applications as lining of pumps with plastics was not invented yet. Thus, the usage of chromium/nickel alloys as an alternative to PFAS/ Fluoropolymer lined pumps with its advantages and disadvantages is well-known. Manufacturing of Chromium/nickel alloys requires deep knowledge and skills from the vendors - here especially foundries - and a profound quality control. The manufacturing and use of these materials results in high cost driven also by limited availability and required quality level of these materials. The environmental impact during manufacturing of special alloys needs to be considered. In addition, the material has a shorter lifetime in comparison to pumps/compressors with plastic inliner. In recent years there has been efforts to develop appropriately fluoropolymer lined pumps in cooperation with the manufacturers. As a result, it is now industrial practice to use the lined pumps in the critical areas with the advantage of An optimized production with low rejection rates, enhancing material efficiency and cost savings Longer service life due to thicker walls and better chemical resistance Extensive applicability due to the increased number of sizes 12/35 covestro.com  Better protection of the environment through usable, hermetically sealed shaft sealing systems (e.g. magnetic coupling) Other coating systems have repeatedly led to problems in pumps. The reasons are manufacturing problems, smaller temperature ranges, and lower chemical resistance. This leads to increased replacement efforts. Rising procurement and maintenance costs caused by higher material and replacement costs, increased monitoring costs for the system and tied-up capital in necessary spare parts and reserve units have also to be considered. This will inevitably lead to a significantly higher price for the final product and reduced competitiveness against imports. 1.4 Cooling conveyer For the cooling of special products cooling conveyers are used. The hot material is fed out of extrusion machines on the conveying belts. The material on the belts is then cooled down by spray water. To avoid the material sticking to the belt and to resist the high temperature, the belt is fluoropolymer coated. After the belts are used they are cleaned, shredded and incinerated under strictly controlled conditions. Alternatives are under investigation; the lifetime and performance must be tested (see chapter 5 to understand typical R&D efforts, development, and potential implementation timeline). 1.5 Feeder In multiples processes Feeders are used to feed components in the production process. In some cases, the feeders or components have fluoropolymer liners to ensure proper operation with mainly sticky materials like e.g., powders. Alternatives had been tested but did not fulfill the required availability and accuracy of the individual feeders. 1.6 Devices for process control and process analysis, controls, and instruments Process Control Technology Fluoropolymers are used in nearly all instruments, control valves and additionally in some specific cables. They are mainly used in coatings, seals, gaskets, in electronic components and especially for control valves in shaft sealings and compression packings in stuffing boxes (see chapter 2.1). Electronic components include printed circuit boards, computer monitors, hard drives etc. and are integral parts of the computerized systems used for process automation and of general-purpose IT equipment. Fluoropolymer coated instrument parts are used for Flow meters, Level meters, Pressure gauges, Control valves. The coatings are necessary for electrical insulation of Magnetic Flow meters or for the prevention of corrosion at instruments like: Free Radar- /Guided Radar Level meters, Tuning Fork Level switches, Magnetic Flow meters, Variable Area Flow meters, Pressure Gauges, Globe valves, Rotary Plug valves and Eccentric Disc valves. Alternatives for electrical insulation could be other polymers, but their suitability regarding the process fluid is very much limited. Alloy or Tantalum could partially be the replacement, but only in few cases as well, due to limitations in the mechanical properties. 13/35 covestro.com Seals, gaskets and fluoropolymers in electronic components are used in all instruments and valve accessories. Those instruments are Transmitters of Flow like: Coriolis, Vortex, Ultrasonic, Thermal, Magnetic, Variable Area; Level like: Free Radar, Guided Radar, Capacitance, Conductive, Nuclear, Buoyancy, Differential Pressure, Electro Mechanical, Hydrostatic, Weight; Pressure like: Gauge pressure, Absolute pressure and Differential pressure; Temperature and Pressure gauges. For valve accessories that are: Solenoid valves, Positioners, Position Feedback devices e.g. with Proximity switches. Possibilities to replace PFAS in such seals, gaskets and electronic components have to be clarified further with the manufacturers of the devices. Process Analyzer Technology (PAT) In PAT all the analyzers have wetted parts as design principle. The majority of analyzers therefore need corrosion resistant coatings, seals and gaskets. Furthermore, the tubing and the fittings for the sample transportation often consist of fluoropolymers, when Stainless Steel is not withstanding the corrosion. An important part of PAT is the preparation of the sample for the analyzer. Here, the important basic steps are heating, cooling, stripping, filtering, evaporation, condensation. As soon as corrosive media are involved, stainless steel cannot be used. Alloy and Tantalum could partially be the replacement, but not in all cases, due to limitations in the mechanical properties. Also pumps for sample transportation often use fluoropolymers for the wetted parts. Specifically peristaltic pumps are built around the tubing and this application cannot be implemented with metallic materials at all. Fluoropolymers are also used in optical windows of analyzers, replacing less performing ceramic materials. Analyzer types, used within the entire chemical industry, which include PFA are: Electrochemical cells, Conductivity probes, pH-probes, Filter-Photometer, Flame Ionization Detectors (FID), Tunable Diode Lasers (TDL), online-titrator, Spectrometer probes. Beside these specialties, in PAT almost all PCT (instrumentation) technologies are used. Alternative materials might be higher alloys, other polymers or in a few cases ceramics. The suppliers would need to develop the alternatives, which in many cases have never been used. 1.7 Valves and accessories, fittings, flaps A major share of all fittings used in the processes include fluoropolymers materials. Again, this is due to the unique properties of fluoropolymers as figured out in the chapters before. Fittings with a PTFE/PFA coating. The coating is needed to protect the fittings against corrosion (see figure 12). A lot of fittings that are coated with fluoropolymers are needed in chlorine production Fittings in which PTFE is used as a shaft seal or as a seal of the end body (ball, cone, etc.; see figures 12-14). 14/35 covestro.com o Stem sealing: Almost all fittings are affected, with the exception of the metallic check fittings (which do not have a shaft seal). o PTFE sealing of the end body: In particular, the ball valves and the plug valves. In the cases above there are currently no alternatives available. After consultation with several manufacturers, there are no alternative solutions or recommendations from their side either. Figure 12: Lined ball valve Figure 13: Plug valve with PTFE Figure 14: Metallic ball valve with PTFE shaft seal 1.8 Filtering candle / multiple tube filter Filters are needed in many applications and are frequently made of fluoropolymers. They are used for gases, fluids and solids. The following examples demonstrate the relevance: Filtering of brine for chlorine production Brine filtration requires stability in various chemical environments: high concentration NaCl-brine in normal operation, potential contamination with chlorine in process offsets, cleaning processes with hydrochloric acid ("acid wash") and hypochlorite solution ("hygiene wash"). Additional stress is given by temperature (up to 80C) and imposed mechanical force by the frequent cleaning by reverse pressure ("back-pulse") Suitable materials are filter candles from rigid porous sintered PTFE, PTFE- membranes on rigid support candles from e.g. C-PVC, PTFE-membranes on support bodies from PTFE-felt or PTFE-cloth/ -fleece operated with a filter aid like alpha-cellulose. Simpler filter materials like PE or PP are available on the market but have heavy-weighting limitations in their chemical stability (not resistant to chlorine break-through or hypochlorite for hygiene wash) or allow only lower operation temperature thus limiting the process efficiency. Metallic materials are not established for this application. Chlorine demister in chlorine production Mist filters are installed in the chlorine treatment to separate liquid droplets from the chlorine gas: after the cooling process, water droplets are separated in the wet demister. The filter material itself is made from glass fibers. Fluoropolymer is a proven material for the support structure of the filter candles. 15/35 covestro.com  Other materials like FRP are of limited mechanical strength and are subject to chemical degradation from chlorine. Other filters and strainers Filer cloths, mesh screens and filter candles are in general used in several applications to remove solid impurities from fluid streams. PTFE, etc. are due to their versatile suitability for a multiplicity of applications, standard materials which have been established for many years. 1.9 Hoses Hoses are used in applications where a permanently fixed piping is not possible. Those are devices where flexibility is needed during operation, this includes: Vessels that have several options to be connected to different flow streams, where the connection has to be changed on a regular basis, so called hosed switching station, or where a separation is needed because of other reasons. Many of the connections of 25 mm diameter and bigger are corrugated metal hoses lined with fluoropolymers. The material combination had been chosen to provide the required safety, and corrosion resistance to the thin metal of the hoses. The lining material is in most cases PTFE. This is especially necessary for hot transfer of corrosive media. In applications of a size smaller than 25 mm besides PTFE, other fluoropolymers are used as liner materials, too. In lined corrugated metal hoses e.g. PVDF is used. Application areas are often analyser or laboratory application. Transparent hoses fully made of fluoropolymers are used in chlorine production, the transparency is required for flow control, especially during start-up of the process. In productions, e.g., chlorine production hoses made of fluoropolymers are at the moment the only suitable material which fulfils the combination of operation requirements like electrical insulation capability, flexibility and corrosion resistance. Until now no alternative materials have been identified that provide the required safety, operability as well as corrosion protection. The hoses are inspected annually and if any damage is recognised, end-of-life material is cleaned, shredded and incinerated under strictly controlled conditions. 1.10 Columns, packings, (chlorine) absorption Fluoropolymers are frequently applied when the chemical conditions in combination with temperature do not allow the utilization of simpler material. Typical process media are wet chlorine, hydrochloric acid, sulfuric acid or brine with dissolved chlorine or oxygen. In some cases, simpler materials like PP, PVC, C-PVC might be applicable but bring along hard restrictions in operation temperature or lifetime. In case of chlorine as process medium the simple materials will have only limited lifetime due to chlorination with significantly higher risks of early failures or leakages. In such cases frequently the handling and disposal of decommissioned equipment is problematic due to the formation of chlorinated hydrocarbons as degradation product. 16/35 covestro.com Some applications with harsh chemical conditions where fluoropolymers are required or preferred: Chlorine drying: o Drying of wet chlorine with concentrated sulfuric acid: Chlorine wet & dry, sulfuric acid o Successfully applied materials: fluoropolymers-lined FRP, fluoropolymerlined FRP in electrolysis plants, fluoropolymer-lined steel in Deacon process, column packing/ internals from fluoropolymer o In electrolysis suitable with restrictions: PVC-lined FRP. Limited to 60 C, requiring higher efforts in process control to avoid temperature offsets. For some special equipment like heat exchanges Alloy C-276 is a suitable material. But a wider application is economically not reasonable. Hypo-decomposition o Decomposition of hypochlorite from chlorine absorption with HCl or sulfuric acid to release the absorbed chlorine. o Successfully applied materials: fluoropolymer-lined FRP. No alternative known. Chlorine scrubber / chlorine absorption: o Absorption of chlorine from process gas (H2 in HCl-DIA-electrolysis) or waste gas by reaction with caustic soda solution to form hypochlorite. Changing chemical environment from pure caustic soda to hypochlorite solution. In the reaction zone intermediate formation of highly corrosive hypochlorous acid is possible. o The Column shell is in some cases made from fluoropolymer-line FRP. An alternative material with good experiences is Titanium, which is several times more expensive. In some cases, pure FRP was installed, but the lifetime is limited due to corrosive attack. o Successfully applied materials for column packing: fluoropolymers in the main reaction zone. o Alternative material for packing: titanium. But: risk of titanium / chlorine fire in case of non-uniform liquid distribution = lack of wetting of the packing. o Standard material for packing in zones with less chemical attack: C-PVC (currently also under an EU REACH restriction scheme) Deacon process, chlorine treatment o The chlorine gas produced by the Deacon process is cooled and scrubbed in contact with hydrochloric acid. The columns are made from a carbon steel shell with fluoropolymer in-liner. Metallic materials or non-fluorinated plastics are not suitable as they are not corrosion resistant. HCl-absorption (HCl-gas from MDI, TDI) o By-product HCl-gas from the production of Isocyanates is absorbed in water / diluted hydrochloric acid to form concentrated hydrochloric acid. o Successful applied material for absorption column: fluoropolymer-lined FRP o Alternative material: phenolic resin. But: single source supply situation, limited lifetime, brittle behavior, risk of early leakages o Packings made from fluoropolymers are typically used. In the past the use of PP packaging led to a very short lifetime Oxygen depolarized cathodes (in chlor-alkali and hydrochloric acid electrolysis) 17/35 covestro.com o The catholyte circuits in the ODC-electrolysis processes work with oxygen as raw-material. The materials of construction must withstand both the circulated electrolyte and the added oxygen. o In the HCl-ODC-electrolysis fluoropolymer-lined FRP is used. Cl2-absorption blowers o Fans (ventilators) to create negative pressure in waste gas collection system / drive waste gas through absorption columns / waste gas scrubber o Blowers (radial ventilators) are designed as metallic construction (carbon steel) with coating. To reach sufficient chemical resistance a surface coating is applied: fluoropolymer spray / sinter-coating. Suitable alternative materials (rubber lining / titanium) are not available on the supply market. Anolyte and Catholyte in HCl-Diaphragm-electrolysis: o HCl 15-30% containing chlorine, chlorine gas, hydrogen with traces of chlorine o Chemical attack and temperature require fluoropolymer-lined FRP as material of construction. o Simple non-fluorinated plastics are not suitable due to the combination of chemical attack and temperature. Decomposition systems (Process, Maintenance, Spot-vents etc.) o Towers are often made of rubber / fluoropolymer lined carbon steel to reach sufficient chemical resistance o Related blowers are also often fluoropolymer-lined 2. Production of nitroaromatics as precursor for isocyanate production One step in the production chain to these isocyanates is the nitration of benzene or toluene to the corresponding nitroaromatics. The nitration reaction is carried out with concentrated sulfuric acid as catalyst and nitric acid as reactant (see Figure 5). Figure 15: Nitration of toluene as example The generated water from nitration dilutes the sulfuric acid. Thus, sulfuric acid needs to be concentrated by evaporation of water before it can be recycled to the nitration reaction (see figure 16). For environmental reasons there is no technical alternative available for sulfuric acid concentration for nitration (see EU "Best Available Techniques (BAT) Reference Document for the Production of Large Volume Organic Chemicals" (LVOC-BREF), chapter 10). 18/35 covestro.com Figure 16: Sulfuric acid concentration scheme As the boiling point of sulfuric acid is quite high, even under vacuum conditions it is >170C, the Sulfuric Acid Concentration (SAC) process is very demanding in terms of materials of construction. The only known materials that are corrosion and reaction resistant to boiling sulfuric acid are Tantalum, Niobium, Glass, Silica carbide and fluoropolymers. Industry standard for sulfuric acid concentration is to use glass lined steel equipment and piping for this severe service. For heat exchanger usually tantalum or Silica carbide is used. But all these materials have the disadvantage that they are not very flexible. To connect these equipment's and pipes a compressible and flexible material is needed that is capable of compensating for thermal stress, given by heating and cooling cycles, and is corrosion and reaction resistant to boiling sulfuric acid, too. In Figure 17 chemical resistance of known gasket materials to hot and concentrated sulfuric acid is depicted. Medium touching gasket material Natural Rubber Styrol-Butadiene-Rubber Nitrilbutadiene rubber Acrylnitril-Butadien-Styrol Low density Polyethylen High density polyethylene Polypropylene Polystyrene Polyvinylchloride Ethylene Propylene Diene rubber Chloroprene rubber Viton Perfluorocarbons Silicone rubber Isobutylene-isoprene rubber Polyetheretherketone PVDF PTFE PFA Graphite Short name Concentrated sulfuric acid 70-93% , T > 120C NR SBR NBR ABS LDPE HDPE PP PS PVC EPDM CR FKM FFKM VMQ IIR PEEK PVDF PTFE PFA C 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 1 2 2 0 0 Not resistant 1 limited restance 2 resistant *Resistance also dependet upon time, temperature, concentration and other impurities Figure 17: Chemical resistance* of common gasket materials to hot and concentrated sulfuric acid4;5;6 4 https://www.curbellplastics.com/resource-library/material-selection-tools/chemicalresistance-of-plastics/ 5 Chemical Resistance Chart For Plastics | Plastic Chemical Compatibility | Curbell Plastics 6 Chemical resistance plays a big factor in material selection. Use Curbell's Chemical Resistance Chart to determine plastic chemical compatibility. 19/35 covestro.com Currently, PTFE/PFA is the only qualified material for sulfuric acid concentration applications. In the SAC units fluoropolymers are used as gasket material to connect fragile glass and/or glass lined steel equipment and piping equipment internals (e.g., for tube sheets in heat exchangers, baffles, dip tubes, demisters, monitoring instruments) to assure safe, efficient and reliable process expansion joints in the piping system to avoid thermal stress which leads to failure of the fragile components with a high risk to employees and environment. Table 1: Usage, expected lifetime and alternative materials of PFAS, own table 3. Fluoropolymers in Chlorine Manufacturing Fluoropolymers are of particular importance in chlorine production. Ten to hundreds of thousands of individual parts in any chlorine production plant are made of or containing fluoropolymers, due to the very high requirements (acidic, caustic, oxidizing, gas-tight, non-conductive, durable). For some of those alternatives exist with certain restrictions and disadvantages (titanium, C-PVC, e.g.) but for the major part no alternatives are known. 3.1 Membranes in Chlor-Alkali Electrolysis Membranes made of perfluorinated sulfonated acids (PFSA)7 are the core of the most common and most efficient chlorine production process within Europe (84.5% share in production capacity in 2022), the chlorine-alkali membrane technology which is "BAT" for chlorine production8 and has set the benchmark of 2.461 MWh per ton of chlorine for indirect cost compensation of CO2 cost from electricity during 7 Chloralkali-Elektrolyse - Wikipedia; Chloralkali process - Wikipedia 8 Best available Techniques Reference Document for the Production of Chlor-Alkali, 2014, Thomas Brinkmann et al., p.25ff, p. 252, JRC Publications Repository - Best Available Techniques (BAT) Reference Document for the Production of Chlor-alkali. Industrial Emissions Directive 2010/75/EU (Integrated Pollution Prevention and Control) (europa.eu) 20/35 covestro.com 3rd emission trading period within EU ETS.9 Membrane technology could be invented because of the development of fluoropolymer-based membranes and enabled phase out of mercury electrolysis. With membrane technology about ~40% of electricity per ton of chlorine produced is saved in comparison to mercury electrolysis. There are no alternative materials for fluoropolymer membranes because of the stress the material must resist: the membranes are contacted with chlorine, caustic and hydrogen which cause very corrosive conditions. On top, the process is operated at a high temperature level of about 90C. Other NaCl chlorine production processes in place are diaphragm technology that relies on a diaphragm made from asbestos (11.5%), the remaining 4% includes hydrochloric acid electrolysis where perfluorinated polymers are core materials, too.10 Fluoropolymer-based membranes in the electrolyzer cells are needed to separate the anode chamber that contains brine and evolves chlorine from the cathode chamber where caustic is formed, and hydrogen is evolved (figure 18). Figure 18: Cell of membrane electrolysis, source: Wikipedia and own adaption The membranes are used in a technical leak-tight plant which is constructed and maintained state-of-the art, and which is operated by well-educated and trained chemical operators under strictly controlled conditions. Membranes must be replaced every 3-6 years due to ageing (e.g., increasing risks of blisters and gas leaks). Used membranes are collected as "chemically contaminated waste". cleaned, shredded and incinerated under strictly controlled conditions. Raw material for chlorine production with membrane technology is NaCl dissolved in water (brine). Working at a current density of 4-6 kA/m and a voltage at 2 to 3 V the membrane is key to separate anode and cathode half-cell to avoid contact of chorine and hydrogen. It is exclusively permeable for Na+ and water, so caustic can be formed which is an unavoidable and important by-product of chlor-alkali based chlorine production (figure 16). 9 Guidelines on certain State aid measures in the context of the greenhouse gas emission allowance trading scheme post-2012 Communication from the Commission -- Guidelines on certain State aid measures in the context of the greenhouse gas emission allowance trading scheme post-2012 (SWD(2012) 130 final) (SWD(2012) 131 final)Text with EEA relevance (europa.eu) 10 Chlor-alkali industry review 2021-2022, Euro Chlor, p. 15 21/35 covestro.com Membranes for NaCl electrolysis need to fulfill all the following criteria: a) Resistant in contact with 32 w-% caustic and hydrogen b) Resistant in contact with acidified brine and chlorine c) No release of harmful components into acidified brine, chlorine and/or caustic (e.g., organic nitrogen compounds) d) Gas-tight to keep the produced gases (hydrogen and chlorine) separated to avoid explosive reactions between these two components, this is key for safety reasons e) Enable Na+ ions to migrate from the anode chamber to the cathode chamber f) Constrict any form of anions (Cl- or OH-) from migrating into the other chamber g) Long-time stable under process conditions in all three dimensions (material efficiency, availability, and operational risks) h) Potential drop over the membrane must be as low as possible (energy efficiency) Only fluoropolymer-based membranes fulfill all these criteria, in fact availability of fluoropolymers enabled the development of membrane electrolysis. No other membrane type is qualified or on the radar screen of R&D for the use in an electrolysis plant based on membrane technology, see again BAT. The use of the fluoropolymer-based membranes is explicitly assessed and proven in the operating permits of those plants, which is a legal requirement according to law. Perfluorinated sulfonated acids-based membranes are the essential foundation of chlor-alkali plants. Chlorine and associated byproduct caustic soda are the backbone of the whole chemical industry - ~70% of the chemical goods are directly or indirectly based on Chlorine chemistry (see Chlorine tree11; For more information, please see the homepage of the European association Euro Chlor12). Chlorine isn't necessarily be incorporated in the final product. Because of its reactivity it can be used to add functional groups in the right place to receive a specific molecule as final product. This is for example the case when producing isocyanates or polycarbonates. Finally, chlorine reacts to HCl or NaCl. HCl is sold on the market, neutralized or recycled as raw material in HCl electrolysis. NaCl is partly recycled and used as feedstock for electrolysis (membrane technology), too. 3.2 Diaphragms in Hydrochloric Acid Electrolysis Diaphragm technology for chlorine production exists with NaCl (brine) and aqueous (aq) hydrochloric acid (HClaq) as feedstock. In comparison to NaCl based diaphragm electrolysis, diaphragm electrolysis with HClaq as feedstock does not use diaphragms containing asbestos because no caustic is involved in the process. Nevertheless, the diaphragms contain fluoropolymers (like PVDF) and PVC, and gaskets are made of fluoropolymers (PTFE) because of corrosive HClaq and the strong oxidizing agent Chlorine. Under the conditions necessary in the production of chlorine via HCl electrolysis diaphragms and gas diffusion electrodes must be replaced every 3-6 years due to aging. 11 02-The-Chlorine-Tree-Infosheet.pdf (eurochlor.org) 12 Home - Eurochlor 22/35 covestro.com Diaphragms and electrodes deemed to be suitable for HCl electrolysis need to fulfill the following criteria: a) Resistant in contact with 18-22% / up to 90C hydrochloric acid solution and chlorine b) No release of harmful components into hydrochloric acid c) Gas-tight to keep the produced gases (hydrogen and chlorine) separated to avoid explosive reactions between these two components. d) Enable H+ ions to migrate from the anode chamber to the cathode chamber e) Long-time stable under process conditions in all three dimensions f) Potential drop over the diaphragm must be as low as possible There are alternative diaphragms that are not in scope of the restriction scheme (PVC-based). However, these diaphragms show a shorter lifetime and inferior longterm gas-tightness (safety relevance) compared to fluoropolymer-based diaphragms. 3.3 Gas diffusion electrodes in Chlor-Alkali / Hydrochloric Acid Electrolysis If the typical hydrogen byproduct of chlorine production is not needed, special types of electrolysis with lower energy consumption in comparison to "conventional" membrane electrolysis or HCl diaphragm electrolysis can be applied: an electrolysis using a gas diffusion electrode (GDE). It is known as "ODC technology", ODC means "oxygen depolarized cathode". Hereby, hydrogen production is suppressed by adding oxygen to the cathode. The cell is slightly different and a different infrastructure for gases (feed and product) is required. Key of the GDE is a porous structure containing hydrophobic and hydrophilic areas, hydrophobic areas allow oxygen gas to enter the hydrophilic water. To build the hydrophobic areas fluoropolymers are needed. Fluoropolymers are the only class of materials which is stable against the corrosive reaction conditions at high temperatures (see chapter 4.3.1 and 4.3.2). No other type of gas diffusion electrode is technically qualified for usage in ODC technology. 3.3.1 NaCl-ODC electrolysis In NaCl-ODC technology the gas diffusion electrodes are placed in the cathode chamber; it separates the gap containing caustic from the gas chamber containing pure oxygen gas. The electrode consists of a porous structure, enabled by the specific properties of PTFE, in which water and oxygen gas must enter and react with electrons at the electro-catalyst to form hydroxide ions which form caustic with the sodium ions crossing the membrane from the anode chamber (figure 19). 23/35 covestro.com Figure 19: NaCl- ODC electrolysis with PTFE- GDE and PFSA membrane, Source: Wikipedia Gas diffusion electrodes to be suitable for NaCl- ODC technology must fulfill the following criteria: a) Resistant in contact with 32 w-% caustic b) No release of harmful components into caustic c) Enable oxygen and water to migrate into the porous system d) Favor oxygen reduction over hydrogen formation e) Long-time stable under process conditions in all three dimensions f) High electrical conductivity Except PTFE there are no alternative materials that fulfil the needs of the electrode for production of chlorine. 3.3.2 HCl-ODC electrolysis GDEs suitable for HCl ODC technology must fulfill the following criteria: a) Resistant in contact with 10% hydrochloric acid solution and chlorine b) No release of harmful components into hydrochloric acid solution c) Enable O2 (gas) and protons (aqueous) to migrate into the porous system d) Favor O2 reduction over H2 formation e) Long-time stable under process conditions in all three dimensions f) High electrical conductivity The GDE is carbon based, with a Rhodium containing electrocatalyst, using fluoropolymer (PTFE and PFSA). Whereas the hydrophobic PTFE is important to achieve the required gas transport and acts as a binder for the powdered catalyst, the ion conduction PFSA (see chapter "4.1 Membranes in Chlor-Alkali Electrolysis") enables the proton migration to the active catalyst sites. There are no substitutes for fluoropolymers available that fulfil all the very challenging needs described above. All electrodes are used in a technically leak-tight plant which is constructed and maintained state-of-the art, and which is operated by well-educated and trained chemical operators under strictly controlled conditions. Under the conditions necessary in the production of chlorine the gas diffusion electrodes must be replaced every 3-6 years due to ageing. The catalyst from used electrodes is recycled according to related environmental / waste legislation. 24/35 covestro.com 4. Emission As described above, we are a user of fluoropolymer materials as part of our production assets. To determine emissions standard analytical methods are needed that deliver representative results in a qualitative and quantitative way. PFAS substances are used in a broad range of different applications. That means, that also targeted methodologies for sampling and analyzing must be developed. Covestro works on a program to cover the potential emissions and has already started first analysis. 5. Waste Management In compliance with waste legislation and permits fluoropolymer materials are collected at the end of their life and treated via incineration/ in a chemical waste incineration plant. 6. Pathway for the potential replacement of fluoropolymers For the development of alternative materials, it is key to bring the right partners on board. Operators of chlorine production plants are, so to say, user of fluoropolymers, the producer of the specific asset, e.g., a membrane for chlorine production, must be involved as well. For a start, different materials that are available on the market have to be chosen and tested in lab scale. If there is no potential candidate found because technical requirements haven't been met at laboratory scale (which is the obvious "low risk" starting scale in a development) new materials have to be designed by, e.g., producing new co-polymers at lab scale, testing other materials then polymers or combining material in a proper way. Therefore, material experts must be part of the project, ideally a lab to produce and characterize the materials that will be tested is available, too. When a material has been identified or designed that meets the criteria in the lab scale, the development for the technical scale starts. To stay with the example of the membrane: a membrane tested in a lab cell, e.g., of about 100 cm, must be upscaled to a membrane of about 2.7 m for thousands of elements. To do so, besides the producer of the membrane, a company that builds machines must be involved into the project to ensure, that this specific kind of material can be produced on the existing machinery and if not since it is a new type of material, to develop a machine that can produce the membrane of this size. When substituting materials, it is not always possible to produce a material that fits into the existing setting. Again, the example of a membrane: maybe the potential new material is very brittle, in comparison to the fluoropolymer, e.g., a ceramic material. Then an upscaling up to a typical 2.7m size would not be possible due to material properties. In this case the whole electrolysis cell where the membrane has to be placed in, must undergo a new development to adapt to the new size of the new membrane. That means that a company that builds electrolyzer cells must be part of the project as well. For industrial application it is very important to be able to develop up to a big scale to be competitive because otherwise the multiplying of asset cost and the cost for operating a multitude of asset can explode. Therefore, the membrane made of the new material must be developed to its maximized size possible. When the steps to develop a membrane and a matching cell are successfully finished, all components have to be assembled into a rack and connected with pipes and cables to collect the products and supply the feed. This is called electrolyzer. Usually, companies that construct cells construct electrolyzers as well, so no additional company is needed. At first, the cell needs to be tested, therefore appropriate equipment and infrastructure is needed. 25/35 covestro.com If membrane materials of a different kind are used in a cell it could happen, that even other production conditions have to be changed, this could be process conditions like pressure and/or temperature, or the needed electrolyte has to be "adapted". This could occur as an obstacle during the project. In addition, other problems may arise that were not previously anticipated. From our experience this is quite normal, so it is advisable to also involve suitable academic partners in the development. It has proven to be a good idea to accompany technological developments from the start with consideration of cost-effectiveness and sustainability. Last but not least, the final modification project (the "implementation") within a larger plant typically requires 4-5 years from (early) planning and engineering phases via permit change approval, detail engineering and execution. In our experience, technology developments require 10-20 years, sometimes even more, depending on their complexity, before they can be used reliably and safely on a large scale. One example is the development of our gas diffusion electrode, it took a good 15 years to successfully test the first pilot electrolyser in Uerdingen (Germany) and another couple of years to industrialize the technology. The concept of the "Technology readiness levels (TRL)" provides good insights over needed steps.13 Conclusion: In view of the large number of applications and uses listed above and the extremely high relevance and value creation, a structured, coordinated, and targeted examination of the individual applications and uses is required. This includes replacement efforts from R&D, lab, piloting to worldscale. Assessment, planning, development and first implementation trials will need several years, so we ask for an exemption of fluoropolymers for our industrial applications. The exemption should not be construed to mean that efforts would stop if the exemption were granted. From today's perspective, however, it is unrealistic to guarantee the complete replacement of fluoropolymers without severely limiting the competitive, safe and compliant operation of plants. 13 Technology readiness level - Wikipedia 26/35 covestro.com 7. Annexes 7.1 Abbreviations PTFE M-PTFE ECTFE PVDF PFA FEP FKM FPM PFCK PVC PVC-C FRP PE PP PAT PCT ODC HCl NaCl NaOH MDI TDI HDI O2 H2 polytetrafluorethylene Modified polytetrafluorethylene ethylene chlorotrifluoroethylene polyvinylidene fluoride perfluoro alkoxy polymer fluorinated ethylene-propylene copolymer fluororubber fluororubber perfluorocarbons polyvinylchloride chlorinated polyvinylchloride fiber-reinforced plastic polyethylene polypropylene Process analyzer technology Process control technology oxygen depolarized cathode hydrogen chloride salt caustic soda methylene diphenyl diisocyanate toluene diisocyanate hexamethylene diisocyanate oxygen hydrogen 27/35 covestro.com CHAPTER II Flame retardant polycarbonate/ polycarbonate based blends 28/35 covestro.com Table of content 1. Introduction ......................................................................................... 29 2. Applications of PC and PC/ABS Blends and Respective Requirements ..................................................................................... 29 3. Potassium Perfluorobutanesulfonate as Flame Retardant for PC ... 35 4. PTFE used in flame retardant polycarbonate/blends ....................... 35 5. Emission .............................................................................................. 35 6. Waste Management............................................................................. 35 1. Introduction Polycarbonate (PC) is the material of choice for applications which have a need for toughness, durability and high temperature stability while meeting required flame-retardant properties, such as electronics, battery housings, fire safety visors or train interiors. Polycarbonate is also used in blend morphologies with toughening polymers, such as PC/ABS (acrylonitrile butadiene styrene) blends. Other blends include PC and PBT (polybutylene terephthalate) and PC with PET (polyethylene terephthalate). Also, these blends underly elevated flame-retardancy requirements for specific applications. With its unique chemical structure, PC can fulfill those requirements when combined with specialized flame-retardants such as perfluorobutanesulfonate (PFBS) and / or the anti-drip polytetrafluoroethylene (PTFE). By using those additives, the important standards for flame retardancy and (consumer) safety can be fulfilled while allowing thin wall design, resulting in material efficiency and sustainability. A 1:1 replacement for these additive uses while keeping the flame retardant and other properties is not known to us from the current state of the art. A restriction of PFAS as currently proposed would therefore result in a reduction of flame-retardancy and, consequently, fire safety as well as increase the endangerment of consumers and workers or lead to non-usability of a fundamental polymer material class that is intrinsically enabling modern applications. We thus request a derogation for PFBS and PTFE for use in PC and PC based blends, while we continue making efforts to identify and validate suitable alternatives. 2. Applications of PC and PC/ABS Blends and Respective Requirements With Internet of Things, Electric Vehicles and autonomous driving, electrical and electronics applications are the driving force for innovation. Electronic products are enablers for digitization and energy transition into renewable energy and smart grids. Applications are manifold, from power generation to sockets, via a grid infrastructure to laptops or smartphones. The shift from combustion-engines to battery electric vehicles is a cornerstone of Europe's climate-strategy, aiming to significantly reduce our greenhouse gas emissions and become carbon neutral by 2050. Electrical and electronic devices contribute to achieving the UN SDGs. 29/35 covestro.com Behind these products are materials that enable manufacturing them to be safe, to have a long service life and to function reliably. Typically, plastic housings with high mechanical performance and high temperature stability protect the electronics. High temperature stability is an intrinsic polymer type property (e.g. as reflected in the glass transition temperature of polymers) that differentiates polymer classes and cannot be achieved by additives/recipes. Polycarbonate is a material class serving high temperature needs where other polymer types (e.g. ABS, Polyolefin, Polyesters) cannot perform. To meet high safety standards (e.g. in case of electronic burning) flame retardant (FR) plastics, such as FR PC and FR PC blends are used. PC and PC blends in particular have a balanced property profile that makes them preferred materials for such applications. High temperature stable and flame retardant (FR) polycarbonates are widely used for various electronic housings, switches and sockets, smart meters, lighting applications, charging stations for EVs, rotary switch boxes, industrial switch gear, visors for firemen's helmets, aircraft and railway construction, home appliances, cameras, robots, mobile network devices and many other electro/electronics and IT applications. Typical applications for PC/ABS blends are notebooks, TVs, battery cell holders and battery modules, smart home devices, intrapartum monitoring devices, respiratory equipment such as oxygen concentrators and CPAP machines, diagnostic imaging equipment enclosures, automated external defibrillator battery case and housing, medication management devices such as infusion pumps and many other medication safety systems and medical devices. Requirements for the material / relevant regulations: The above-mentioned applications need to fulfill specific standards and regulations, e.g. Applications Product and Test Standards Fire helmets EN 443:2008 Household appliances IEC 60335 Audio/video, information and communication IEC 62368 technology equipment Wide used test for material classification IEC 60695-2-10 and requirement for electrical applications Wide used test for material classification UL94 and other ASTM standards Building fire performance class EN 13501 Medical Electrical Equipment EN 60601-1-2 Example of flame retardancy test: A widely applied test standard is the UL94 regulation ,,Tests for Flammability of Plastic Materials for Parts in Devices and Appliances". For most applications in Electro/Electronics applications a V-0, or V-1, and/or 5V (5VB and 5VA) rating is required. For most home appliance applications, Glow Wire Flammability Index (GWFI) or Glow Wire Ignition Temperature (GWIT) tests are required. The UL94-V test standard gives different ratings depending on the performance of the specimen (test material). Different product standards refer to these ratings. Rating and test V-0 criteria Burning time of each within 10 seconds individual test specimen (after first V-1 within 30 seconds V-2 within 30 seconds 30/35 covestro.com and second flame application)* Burning and within 30 seconds within 60 seconds within 60 seconds afterglow times after second flame application* Dripping behavior of No dripping with no No dripping with no drips of flaming burning specimens* ignition of cotton ignition of cotton particles are batting batting allowed Application and Support of current Sockets with USB Cable splices product standard carrying parts in port (IEC 62368) (UL2459) circuit breakers (UL508) * source Combustion (Fire) Tests for Plastics | UL Further test ratings: 5VB: Burning and afterglow times of specimens are less than 60s after the fifth time a flame is applied. No burning drips allowed. 5VA: Burning and afterglow times of specimens are less than 60s after the fifth time a flame is applied. No burning drips allowed. No hole formation is allowed. Glow Wire Flammability Index (GWFI): Flame or glowing must selfextinguish within 30 seconds after removal of the glow wire. No burning drips allowed. Temperature of glow wire is set depending on application between 550 and 960C. Glow Wire Ignition Temperature (GWIT): No flame or glowing for more than 5 seconds while the glow wire is applied. No burning drips allowed. Temperature of glow wire is set depending on application between 550 and 960C. Further important properties that need to be maintained with flame retardant agents In addition to the above-mentioned flame-retardant properties, there are other requirements important to industries which can be fulfilled very well by PC or PC blends. Suitable materials need constant properties over a wide temperature range, like mechanical properties and dimensional stability with very low thermal expansion. Polycarbonate shows no post molding shrinkage in comparison to other polymers such as Polyamide (PA) and Polybutylene terephthalate (PBT). To reduce post shrinkage and to show constant properties over a wide temperature range glass fiber is often added to PA and PBT, but the added glass fiber increases the density / weight significantly and reduces resource efficiency. Dimensional precision of such alternatives remains unsatisfactory for critical parts. Polycarbonate is a transparent material that also remains transparent with suitable FR package. Polycarbonate has a high heat resistance and better flowability compared to Poly(phenylene oxide) (PPO) / high impact polystyrene (HIPS) grades. For many applications, excellent optical properties, e.g. high light transmission, are required. PC in its applications has a long service life supporting sustainability targets. Examples of applications enabled by flame retardant polycarbonates Charging stations for electric vehicles 31/35 covestro.com Not just since the EU ban on gasoline and diesel-powered new cars from 2035 have electric vehicles become an integral part of traffic. In addition to private cars, scooters or bicycles, there are numerous sharing offers that make electric means of transport accessible to a broad mass. A comprehensive infrastructure for charging these vehicles is therefore indispensable today and in the future. As current-carrying devices, some of which are used outdoors, such charging stations must fulfill numerous safety aspects. The market requirements include flame retardancy (5VA according to UL94), weather resistance (f1 listing according to UL 746C), impact strength, good flowability in processing and dimensional stability thereafter. Therefore, for these products / applications, primarily flame-retardant polycarbonates are used. Possible alternative semicrystalline FR materials need to include glass fibers, to at least partially mitigate the higher warpage and shrinkage these materials have and to increase their stiffness at high temperature. This addition of a filler affects other properties, e.g., impact behavior. As charging stations have to fulfill standardized impact tests it is in question if these requirements could ever be met using glass fiber (GF) filled semicrystalline FR materials. Furthermore, the warpage of these materials, despite the addition of GF, is significantly higher than that of PC. Especially for large parts that have to fulfill small tolerances, such as housings of EV chargers, this may cause massive problems in production, assembly and product safety during lifetime. Additional glass fibers massively reduce the recyclability of the materials and result in less sustainable products. Mobile network infrastructure One of the core requirements for digitalization is access to the Internet at any time with high data quality/quantity. The requirement for this, in turn, is a corresponding technical infrastructure, which is characterized by powerful mobile network infrastructure (4G, 5G, Wi-Fi). Similar to charging stations, high requirements apply here in terms of flame retardancy (V-0 according to UL94) due to high energy consumption and heat generation, especially in urban and indoor environment, weather resistance (f1 listing according to UL 746C), impact strength, good flowability in processing and dimensional stability thereafter. In addition, the materials used must have a high transmissivity for the signals. Flame-retardant polycarbonates are the most suitable option here, with which all technical functionalities are sufficiently fulfilled. Transparent components in public transportation As an alternative to private transport, public means of transportation such as trains are becoming increasingly important in times of climate change. In terms of energy efficiency and the associated CO2 emissions, a low weight of the vehicles while guaranteeing all safety requirements is of utmost importance. Plastics are the material of choice for this purpose. Particularly in the area of transparent components, such as lighting or wall elements, to the best of our knowledge, only flame-retardant polycarbonates meet the high safety requirements (e.g. EN45545, NFPA130). Those include strict limits for smoke density, spread of flame, occurrence of burning droplets of molten plastic and toxicity of combustiongases. Glass as an alternative material would lead to a doubling of the weight for these components, furthermore glass is not shatter resistant and there is more danger in case of vandalism. Fire helmets: Meeting increasingly strict safety standards Firefighter helmet visors have very high safety standards and need to be particularly heat resistant. Polycarbonate fulfils those safety requirements while maintaining toughness and good optical properties. As requirements for these helmets become stricter, manufacturers need materials with even higher flameresistant properties. Specialized helmet manufacturers typically choose an Apec 32/35 covestro.com FR type high-performance polycarbonate, which meets the thermal requirements defined in the standard EN 443:2008 for firefighters' helmets. The required heat resistance is tested with hot metals (950C steel ball for 10 s, 650C steel rod 5s) and heat radiation (14 kW/m for 180s) to safeguard fire fighters. Charger and adapters: protect consumer from electric strikes Chargers and adapters power are necessary for a wide range of electronic devices, electric tools, and appliances. Charger housings need to keep pace with new technologies like fast-charging components that increase the device's temperature. Because they make direct contact with electrical current carrying parts and must have an insulating characteristic. Materials must also satisfy strict IEC test requirements for fire hazards and glow wires for consumer safety. Tough, non-flammable thermoplastics like polycarbonate, PC blends and resins can fulfill these requirements only with the support of FR agents. In addition, most products enable the use of laser markings or direct pad printing on them. Grades for batteries and chargers comply with UL 94 V-0 at 1.0 mm and are RTI-rated (Relative Temperature Index as defined in UL746B) above 100C. RTI indicates the maximum service temperature according to UL. It is tested at which temperature the material maintains at least half of its properties in a long-term thermal ageing program compared to a material with known retention. To the best of our knowledge, the dominant portion of all charger applications are made from FR PC based materials. Housings for Notebooks Polycarbonate blends have to show a balanced property profile for consumer electronic housings e.g. notebooks. The contained sensitive electronics and high energy containing Lithium-Ion battery must be protected to different impact scenarios, beside other key requirements like design freedom in combination with color. Subsequently used materials need to be tough and impact resistant. To fulfill consumer protection and safety standards structural parts have to fulfill mechanical drop tests, must show a good chemical resistance and have to meet flame-retardant test, e.g. UL94 V0 in thin wall thickness. For some brands also sustainability is of value e.g. meeting requirements on eco-labels with recycled content and e.g. no brominated substances. This whole set of requirements can only be met with certain PFAS as flame retardant / anti-drip in PC or PC-blends as safety is ensured and low amounts of additives secured. PC and PC blends can be used for notebook housing as well as for enclosure for exchangeable LithiumIon batteries. PC based flame-retardant materials are the material of choice for the whole notebook industry. If PFAS was banned, the whole industry would need to undergo a significant change. Either a significant reduction in safety standards would need to be considered or a move towards aluminum. Shaping aluminum is a complex task taking into account limitations of production scale, overall engineering options, the (explosive) dust generation and the availability of equipment / service providers. The sustainability related advantages of PC use vs. aluminum use are currently being described in the industry. Because of the excellent flammability performance of PC grades and the very good experience as Lithium-Ion battery enclosure in notebooks, the same PC grades are used for cell holder material for home energy storage systems or as clamshell for exchangeable battery systems (e-bike battery, GreenPack). In existing and future electric vehicle applications the material is also used as cell holder material because of its excellent flame-retardant performance and good property retention over a wide temperature range. Housing for HealthCare Industry Flammability requirements for housing materials are mainly based on UL preselection tests like UL94-V. In the HealthCare industry devices like CPAP 33/35 covestro.com (continuous positive airway pressure) or oxygen concentrators require flame retardant PC based housing materials. Due to compliance with UL94, safety hazards are significantly reduced especially related to potential malfunctions of the device that can lead to self-ignition. The PC based FR materials extinguish or retard the fire spread so everybody can escape and reach a safe location in case of a fire. This is of high importance especially in a hospital environment where not all patients can move freely. Monitors Flammability requirements are mainly based on UL pre-selection tests like UL94V. In the past, for TV-housings these fire safety requirements were not in place. Often you read in fire department and insurance reports, the origin of the fire was a defect TV. Today, there is e.g. IEC62368 which requires FR testing for TV housings. Industry has thus shifted from non-FR materials, like e.g. ABS, to flame-retardant PC blends. Also, computer monitors which can have nowadays the same function for people are made of flame-retardant PC-blends, which extinguish or retard the fire spread so everybody can escape and reach a safe location in case of a fire. Energy storage systems at residential / industrial scale In order to decrease the effect of greenhouse gases, renewable energies are a key to stay away from fossil fuels. Energy must be stored and fluctuations must be dealt with in a controlled manner via energy storage systems. These systems range from the ones installed at home connected to a home-solar system to the ones on an industrial scale connected to solar panel fields or even wind energy, so the energy can be well transferred to the grid in an efficient fashion. Energy storage systems must be safe in service and a lot of this depends on Lithium-ion batteries that must be protected by internal and external housing. The requirements for these internal and external housings must fulfill numerous safety aspects such as flame retardancy (UL94), impact strength, dielectric properties, good processability and dimensional stability in service. Hence, for these electric and electronic housings primarily flame retardant polycarbonate blends are used. A possible alternative could be semicrystalline flame retardant materials that must include glass fibers to mitigate the high warpage of the parts in service. Possible warpage however could lead to parts malfunctions. Moreover, the addition of a filler affects other properties, e.g. impact behavior. Furthermore, the warpage of these materials, despite the addition of glass fiber, is significantly higher than that of polycarbonates and blends. Especially for complex parts that have to fulfill small tolerances, such as battery cell holders, which might cause production problems, assembly, and lifetime safety. Additional glass fibers massively reduce the recyclability of the materials and result in less sustainable products. Covestro products: https://solutions.covestro.com/en/brands/makrolon https://solutions.covestro.com/en/brands/bayblend Published Case studies for flame retardant polycarbonates and blends: https://solutions.covestro.com/en/highlights/articles/theme/applications/protective -apparel https://solutions.covestro.com/en/highlights/articles/stories/2021/choosing-theright-engineering-plastics-for-prismatic-battery-packs 34/35 covestro.com 3. Potassium Perfluorobutanesulfonate as Flame Retardant for PC Potassium perfluorobutanesulfonate, CAS-Nr. 29420-49-3 (PFBS) is used as a flame retardant for polycarbonates. Polycarbonate has a good intrinsic flame retarding performance which needs to be further enhanced with the addition of very small amounts of the FR agent PFBS. This is a unique chemical for this use profile, is almost exclusively used in PC matrix and has found no alternative since its discovery in the 1980s to our knowledge. Formulations with PFBS show excellent flow behavior and enable thin wall designs making devices lighter yet tougher while meeting safety requirements and aesthetics. Market and customer requirements trend toward increased FR requirements with thinner construction. Formulations containing PFBS enable lower material consumption without compromising fire safety performance. But still, FR properties must be kept to assure the safety and protection of consumers and other users of the device (e.g. employees and technicians). Furthermore, PFBS does not contain brominated and chlorinated moieties as formerly used and meanwhile regulated FR agents. We are not aware about suitable alternatives. As a consequence, we ask for an unlimited derogation. 4. PTFE used in flame retardant polycarbonate/blends PTFE is a low volume % polymeric ingredient of polymer compound recipes which is used to modify the rheology of the polymer melt and especially impacts the dripping behavior during burning. PTFE has the advantage of forming fibrils (fibrillation) during processing and enhancing the melt strength during burning, causing shrinkage of melt. It thus prevents dripping of the burning melt. This behaviour is unique and not known to other usable polymers. We are not aware of suitable alternatives for this application As a consequence, we must ask for an unlimited derogation. 5. Emission See therefore the public contribution under Chapter I: 4. Emission, page 25 6. Waste Management See therefore the public contribution under Chapter I: 5. Waste Management, page 25 35/35 covestro.com