Regulation FD Disclosure (Form 8-K)

Item 7.01. Regulation FD Disclosure.

On September 15, 2025, ASP Isotopes Inc. (the "Company" or "ASP Isotopes") extended the date for the fulfillment of the conditions to the previously announced offer by the Company to acquire 100% of the ordinary shares (excluding treasury shares) of Renergen Limited ("Renergen"), a South African company listed on the exchange operated by the JSE Limited and the Australian Securities Exchange, pursuant to a scheme of arrangement under South African law pursuant to which Renergen shareholders will receive 0.09196 new ASP Isotopes shares for each Renergen share held on the record date (the "Scheme").

The Company has extended the longstop date from September 30, 2025 to November 28, 2025 in order to allow the parties additional time to satisfy conditions to closing relating to the receipt of the remaining required regulatory approval and certain third party consents. As of September 15, 2025, the implementation of the Scheme remained subject to the approval of the Financial Surveillance Department of the South African Reserve Bank (FinSurv) as provided for in the South African Exchange Control Regulations (in terms of the South African Currency and Exchanges Act, 1933). The Company and Renergen continue to pursue a timely approval of the Scheme with FinSurv and certain third parties in order to implement the Scheme as promptly as possible.