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FILTRATION / PFAS Follow-up of KEMI - Ahlstrom-Munksj call on Oct. 20th, 2021 CONFIDENTIAL PROPRIETARY INFORMATION OF AHLSTROM-MUNKSJO Content Air filter classification and multi-stage filtration systems ePTFE PFPE/C2 C4 Air filter classification and multistage filtration systems Air filter classification* CONFIDENTIAL The main determinant to select an air filter is its filtration class, which is determined by its particulate filtration efficiency performance. The air filter classification covers a wide range of particulate filtration efficiency levels: from coarse (65% of > 10 m particles) to medium, fine and EPA/ HEPA/ ULPA filters (100% of < 1 m particles). This classification allows to find the optimal performance to: filter particles of a certain size i.e., from > 10 m up to 0.3 m meet air quality requirements/standards in downstream applications optimize dust collection to achieve high dust holding capacity and longer life-time reduce pressure drop properties to ensure low energy consumption and CO2-emissions Each filtration class has a given role in air filtration systems and, therefore, it is not technically wise to replace coarse, medium or fine filters by higher efficiency filters (e.g. EPA/HEPA/ULPA). *Liquid filtration also relies on multi-stage filtration with different levels of efficiency and standards than for air filtration, which also rely on C6 (e.g., removal of water droplets from fuel). 4 Filtration media per air filter classification Particle size filtered > 10 m > 2,5 m > 1 m ~ 0.3 m . Increasingly efficient to filter increasingly fine particles Particulate Filtration Efficiency Filter classes Coarse filters G1 - G4 or ISO Coarse >40% Medium filters M5 - M6 or ISO ePM10 - ePM2,5 >70% Fine filters F7 - F9 or ISO ePM1 > 85% >99.95% EPA filters E10 - E12 HEPA filters H13- H14 CONFIDENTIAL 99.999995% ULPA filters U15-U16-U17 AM Filtration media technology HVAC/ GT/ APC1,2,3 Classification according to EN779 or ISO 16 890 AM CellTech platform (=filter paper) High Purity HVAC/ GT/ APC1,2,3 Classification according to EN1822 AM Trinitex platform (=synthetic nonwoven) AM Microglass platform 1 HVAC: Heat Ventilating and Air conditioning System 2 GT: Gas Turbine 3 APC: Air Pollution Control 5 AM ePTFE products C6-treated Multi-stage filtration system: Example of static GT-filtration From coarse to high filtration efficiency In static GT-filtration applications, each filtration stage requires a C6-treatment on the media to achieve waterrepellence and oil-repellence C6-treated microglass media is the benchmark technology for the 3filtration stages. C6-treated synthetic media can be used for pre-filtration and fine-filtration stages. Source: Freudenberg Typically C6-treated microglass media or synthetic media 6 Typically C6-treated microglass media ePTFE membranes A AHLSTRQM MUNKSJO ePTFE filter overdesign CONFIDENTIAL ePTFE membranes can only be used for EPA/ HEPA filters (i.e. not for coarse, medium and fine filters) Replacing medium or fine filters by ePTFE filters will lead to the following consequences: Lower dust holding capacity* leading to 2 to 3 times more frequent replacement of filters due to increasingly fast loading and filter clogging, as the pore size is smaller. 2 to 13 times increased pressure drop** leading to increasing energy consumption, as more energy would have to be supplied by the filtration units in order to push the air flow through the filter. Filter class H14 media with ePTFE F9 media (microglass or synthetic) M6 media (microglass or synthetic) Dust holding capacity, DHC at 300 Pa [g/m] 11-17 32-37 30-45 Pressure drop, DP at 5,3 cm/s [Pa] 134-156 40-70 10-20 *The maximum quantity of dust that can be retained by a filter, which is strongly correlated with filter life time and thus with early replacement of filters. **If pressure increases when the air is trying to get through a filter, there is higher resistance to flow. 8 CONFIDENTIAL ePTFE repellency performance: Lower water- and oil-repellency Water-repellent performances [mm of water column] 1000 750 C6-treated filter media (microglass, cellulose, synthetic nonwovens) When higher repellent properties are required, an additional C6-treatment is applied onto the ePTFE membrane. 500 ePTFE 250 membranes 1 23 4 5 6 7 8 9 10 11 Oil-repellent/ Gluerepellent performances [acc. To AATCC118] 9 Socio-economic implications of transitioning to ePTFE CONFIDENTIAL Increased consumption of PFAS: ePTFE contains ca. 10 times more PFAS than a microglass media treated with C6 (cf. table below). HEPA C6-treated microglass media 0,15 g of PFAS/m ePTFE Multi-layer structure 1-2 g of PFAS/m Concerns regarding production and requalification: It is easier to change the chemical additives used in the production process (e.g. C6) than the filtration media (e.g. microglass vs ePTFE membranes) A change of the filtration media will require a complete change of production lines for filtration media producers. It will also force filter manufacturers to change their pleating technology, leading to investments in new pleating lines i.e., from rotary pleaters (=benchmark technology to pleat microglass media) to knife pleaters (=benchmark technology to pleat ePTFE-based filtration media). This shift will come with a loss of productivity since pleating speed is lower with knife pleaters. This may also lead to redesigning of the filter element and additional requalification by downstream users. 10 Socio-economic implications of transitioning to ePTFE CONFIDENTIAL Broader socio-economic implications: ePTFE filters will be min. 6 times more costly. ePTFE is only an affordable option in niche markets where microglass media do not meet specific requirements (e.g., special segments of APC or glass-free requirements for cabin and HEPA filtration applications, high mechanical strength for Pulse-Jet GT) ePTFE filters account from 2% to 5% of filtration cartridge market shares depending on the filtration application ePTFE membranes are widely used in filters bag in APC applications, which account for 85% of the filters used in these applications. AM is not present on the filter bag market. Bag filters (on the left) and APC filter units with bag filters (on the right) Application where ePTFE membranes are widely used. AM is not present on that market 11 Cartridge filters (on the left) and APC filter units with cartridge filters (on the right) Application where AM is present and where ePTFE membranes are marginal PFPE/ C2 A,AHLSTROM MUNKSJO Perfluoropolyether (PFPE, also know as C2) C2 does not represent a suitable alternative to C6 due to the following reasons: C2 treatment costs min. 4 times more than C6-treatment -The price of the chemical is minimum twice the one of C6 -The dosage has to be doubled to achieve acceptable repellent properties Lower repellent properties despite increased dosage (cf. table below) CONFIDENTIAL Repellent agent PFAS content in the final product H2O Repellency mmH2O Oil Repellency - Kit 3M # C6 1.75% 1100 9/10 PFPE/ C2 3.5% 600 7 Only one reliable chemical supplier identified, which is at high risk of production discontinuation due to its heavy reliance on food packaging applications (as PFAS-free alternatives are available for this use). 13 C4 A AHLSTRQM MUNKSJO C4 CONFIDENTIAL C4 side-chain fluorinated polymers: To the best of our knowledge, they are not commercially available on the market. They are not proactively offered by C6-suppliers as alternatives to C6. They have not been tested by AM, but we anticipate a lower WOR based on the transition from C8 to C6. C4 sulphonate chemistry: Seems to be available on the market, although it has never been offered as a solution by suppliers. It can degrade into perfluorobutane sulfonic acid (PFBS) which, unlike PFHxA, is listed as a Substance of Very High Concern (SVHC). No R&D work expected due to worse hazard profile. 15