Form 8-K Current Report ASP ISOTOPES INC. (Incorporated in the State of Delaware, United States of America) (Delaware file number 6228898) Ticker Symbol: NASDAQ: ASPI ISIN: US00218A1051 LEI: 6488WHV94BZ496OZ3219 JSE Share Code: ISO ("ASPI" or "the Company") FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934, ASPI stockholders are advised that a Form 8-K has been filed with the U.S. Securities and Exchange Commission. On September 15, 2025, the Company 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. A copy of the Form 8-K can also be found at: Inline Viewer: ASP Isotopes Inc. 8-K 2025-09-15 15 September 2025 Sponsor Valeo Capital Proprietary Limited Date: 16-09-2025 07:05:00 Produced by the JSE SENS Department. The SENS service is an information dissemination service administered by the JSE Limited ('JSE'). The JSE does not, whether expressly, tacitly or implicitly, represent, warrant or in any way guarantee the truth, accuracy or completeness of the information published on SENS. The JSE, their officers, employees and agents accept no liability for (or in respect of) any direct, indirect, incidental or consequential loss or damage of any kind or nature, howsoever arising, from the use of SENS or the use of, or reliance on, information disseminated through SENS.