AirSCWO Destroys PFAS - Permanently

Unlike conventional treatment approaches that filter or concentrate PFAS, AirSCWO permanently destroys organic contaminants. Results were evaluated by a third party and presented by Arcadis, a global leader in environmental engineering, which served as the Company's independent project partner.

"Performing technical demonstrations at scale, such as this DIU project, are essential to build trust within government agencies," said Howard Teicher, the Company's VP, Government. "Watching AirSCWO PFAS-contaminated waste streams, in some cases to a NON-DETECT or single-parts per trillion level, affirms that this technology is ready for operational use."

AirSCWO was evaluated with six distinct PFAS-contaminated waste streams and met or exceeded every key performance objective. Results were evaluated by a third party and presented by Arcadis, a global leader in environmental engineering, which served as the Company's independent project partner. These wastes are the types of concentrated, hard-to-treat waste streams generated at military bases, industrial facilities, and municipal water systems nationwide. The independently validated results demonstrate that AirSCWO achieved greater than 99.9% destruction and removal efficiency ("DRE") across all four highly concentrated PFAS liquid waste streams, and greater than 90% DRE for solid waste streams:

Allonnia SAFF40 Foam Fractionate - Total PFAS DRE of 99.9998%, with effluent concentrations at or below method detection limits across all primary analytes

Cyclopure DEXSORB Media Regenerant Still Bottoms - Aggregate PFAS DRE of 99.95%, exceeding 99.99% for PFOS, PFOA, PFHxS, and 6:2 FTS

ECT2 SORBIX RePURE IX Regenerant Still Bottoms - Aggregate PFAS DRE of 99.996%

AFFF (Aqueous Film Forming Foam; C8 & C6 Blend) - Aggregate PFAS DRE of 99.997%, exceeding 99.999% for PFOS, PFOA, and 6:2 FTS

Spent AIX/GAC Mixture - Over 97.5% aggregate PFAS DRE, exceeding 99.5% for PFOS and PFOA

Spent GAC - Aggregate PFAS DRE greater than 90%, exceeding 99.9% for PFOS and PFOA

All testing followed EPA Method 1633 for liquid-phase PFAS analysis, with supplemental air emissions monitoring conducted via multiple validated federal methods. Critically, hydrogen fluoride stack emissions were non-detectable across all six tests - confirming that AirSCWO fully mineralizes these highly recalcitrant fluorinated organic compounds with no hazardous air emissions.

"These results represent a defining moment for AirSCWO and for the PFAS destruction market as a whole," said Dr. Raj Melkote, Chief Technology Officer for 374Water Inc. "What Arcadis and Clean Earth helped us demonstrate is not just that AirSCWO works - it's that it works across the hardest waste streams, under the most rigorous federal protocols, with third-party analytical data that leaves no room for ambiguity. That we can reduce 75,000,000 nanograms per liter of PFOS in firefighting foam down to less than 120 parts per trillion (less than the reporting limit) is not a theoretical laboratory result. It represents full-scale performance, independently verified, with real-world scenarios and at the exact conditions the market demands. We expect to see the industry respond strongly to this data."

A Large and Growing Market Opportunity

The PFAS problem spans virtually every segment of the water and waste management industry from military installations remediating impacted soil and groundwater, to municipal utilities facing costly biosolids disposal constraints, to landfill operators handling billions of gallons of PFAS-laden leachate each year. Regulatory pressure to move beyond conventional approaches toward permanent destruction solutions is accelerating rapidly, driven by tightening federal and state discharge limits, liability uncertainty and public health concerns.

Importantly, conventional technologies don't destroy PFAS - they concentrate it, creating a residual waste problem that still needs to be solved. AirSCWO is the final step in that treatment chain: receiving the concentrated PFAS residuals that other technologies produce and permanently destroying them and thus eliminating all long-term risks associated with these wastes.

The full results were publicly presented at the Northeast Waste Management Officials Association ("NEWMOA") Science of PFAS Conference on April 16, 2026, by Baxter Miatke, PE, PFAS Treatment Technology Lead at Arcadis, and Lauren March, PE, PFAS Destruction Subject Matter Expert at Arcadis.