ASP Isotopes Inc. 10-K

Item 9A. Controls and Procedures Disclosure Controls and Procedures Our management, with the participation of our Chief Executive Officer and Chief Financial Officer, evaluated the effectiveness of our disclosure controls and procedures as of December 31, 2025. The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act, mean controls and other procedures of a company that are designed to ensure that information required to be disclosed by us in the reports that we file or submit under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms. Disclosure controls include, without limitation, controls and procedures designed to ensure that information required to be disclosed by a company on the reports that it files or submits under the Exchange Act is accumulated and communicated to management, including, our principal executive and principal financial officers, as appropriate, to allow timely decisions regarding required disclosure. Management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives and management necessarily applies its judgement in evaluating the cost-benefit relationship of possible controls and procedures. Based on the evaluation of our disclosure controls and procedures as of December 31, 2025, our Chief Executive Officer and Chief Financial Officer concluded that, as a result of material weaknesses identified in our internal control over financial reporting, our disclosure controls and procedures were not effective as of December 31, 2025 . In the course of preparing the financial statements that are included in this Form 10-K, management has determined that material weaknesses exist within the internal controls over financial reporting. The material weakness identified relates to the lack of formal control documentation and consistent execution of control procedures, and the lack of a sufficient complement of personnel within the finance and accounting function with an appropriate degree of knowledge, experience and training. We also noted a material weakness related to logical security and privileged access in the area of information technology. We concluded that the material weaknesses in our internal control over financial reporting information technology occurred because, prior to becoming a public company, we were a private company and did not have the necessary business processes, systems, personnel, and related internal controls necessary to satisfy the accounting and financial reporting requirements of a public company. In order to remediate the material weaknesses, we expect to enhance our formal documentation over internal control procedures and management controls infrastructure to allow for more consistent execution of control procedures and hire additional accounting, and finance and information technology resources or consultants with public company experience. We may not be able to fully remediate the identified material weakness until the steps described above have been completed and our internal controls have been operating effectively for a sufficient period of time. We believe we have already and will continue to make progress in our remediation plan during the year ending December 31, 2026, but cannot assure you that we will be able to fully remediate the material weakness in 2026. If the steps we take do not correct the material weakness in a timely manner, we will be unable to conclude that we maintain effective internal control over financial reporting. Accordingly, there could continue to be a reasonable possibility that a material misstatement of our financial statements would not be prevented or detected on a timely basis. We also may incur significant costs to execute various aspects of our remediation plan but cannot provide a reasonable estimate of such costs at this time. Management’s Annual Report on Internal Controls Over Financial Reporting Our management is responsible for establishing and maintaining adequate internal control over financial reporting (as such term is defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act). Our internal control system was designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes, in accordance with generally accepted accounting principles in the United States. Due to inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness of the internal control over financial reporting to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with policies and procedures may deteriorate. Our management, under the supervision and with the participation of our chief executive officer and chief financial officer, evaluated the effectiveness of our internal control over financial reporting as of the end of the period covered by this Annual Report on Form 10-K based on the framework in Internal Control---Integrated Framework (2013 framework) issued by the Committee of Sponsoring Organizations of the Treadway Commission, or COSO. Based on such evaluation, our management concluded that our internal control over financial reporting was not effective as of the end of the period covered by this Annual Report on Form 10-K due to the material weaknesses described above. 146 This Annual Report on Form 10-K does not include an attestation report on internal control over financial reporting issued by our independent registered public accounting firm. Our auditors will not be required to opine on the effectiveness of our internal control over financial reporting pursuant to Section 404(b) of the Sarbanes-Oxley Act of 2002 until we are no longer an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012. Changes in Internal Control Over Financial Reporting There has been no change in our internal control over financial reporting as such term is defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act during the quarter ended December 31, 2025 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting. Item 9B. Other Information Trading Arrangements of Section 16 Reporting Persons. During the quarter ended December 31, 2025, the directors and officers of the Company (as defined in Rule 16a-1(f) of the Exchange Act) adopted or terminated the contracts, instructions, or written plans for the purchase or sale of our securities set forth in the table below. Name and Title Action Adoption/ Termination Date Rule 10b5-1 (1) Non-Rule 10b5-1 (2) Total Number of Shares of Common Stock to be Sold (3) Expiration Date Heather Kiessling ( Chief Financial Officer ) Adoption December 19, 2025 X — Up to 92,496 April 14, 2027 Paul E. Mann ( Chief Executive Officer and Executive Chairman ) Adoption (4) December 30, 2025 X — 1,005,100 March 3, 2027 Duncan Moore ( Director ) Adoption December 31, 2025 X — 11,462 April 16, 2026 (1) Contract, instruction or written plan intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act. (2) “Non-Rule 10b5-1 trading arrangement” as defined in Item 408(c) of Regulation S-K under the Exchange Act. (3) Rule 10b5-1 trading arrangements that are intended to provide for “eligible sell-to-cover transactions” (as described in Rule 10b5-1(c)(1)(ii)(D)(3) under the Exchange Act) to satisfy tax withholding obligations arising exclusively from vesting of restricted stock awards (RSAs). (4) The adoption of the Stock Sale Plan, dated December 30, 2025, by Mr. Mann also terminated his Stock Sale Plan, dated December 13, 2024. Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections None. 147 PART III Item 10. Directors, Executive Officers and Corporate Governance The information required by this item will be included in an amendment to this Annual Report on Form 10-K or incorporated by reference from our Proxy Statement to be filed pursuant to Regulation 14A within 120 days of the end of the fiscal year covered by this Annual Report on Form 10-K. You can find our governance documents, including our corporate governance guidelines and our code of business conduct and ethics, on our website www.aspisotopes.com under “Investor - Governance - Governance Documents.” Our Board regularly reviews and updates our governance materials in light of legal and regulatory requirements, evolving best practices and other developments. We intend to satisfy the disclosure requirement under Item 5.05 of Form 8-K regarding amendment to, or waiver from, a provision of our code of business conduct and ethics by posting such information on the website address and location specified above. Item 11. Executive Compensation The information required by this item will be included in an amendment to this Annual Report on Form 10-K or incorporated by reference from our Proxy Statement to be filed pursuant to Regulation 14A within 120 days of the end of the fiscal year covered by this Annual Report on Form 10-K. Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters The information required by this item will be included in an amendment to this Annual Report on Form 10-K or incorporated by reference from our Proxy Statement to be filed pursuant to Regulation 14A within 120 days of the end of the fiscal year covered by this Annual Report on Form 10-K. Item 13. Certain Relationships and Related Transactions and Director Independence The information required by this item will be included in an amendment to this Annual Report on Form 10-K or incorporated by reference from our Proxy Statement to be filed pursuant to Regulation 14A within 120 days of the end of the fiscal year covered by this Annual Report on Form 10-K. Item 14. Principal Accounting Fees and Services The information required by this item will be included in an amendment to this Annual Report on Form 10-K or incorporated by reference from our Proxy Statement to be filed pursuant to Regulation 14A within 120 days of the end of the fiscal year covered by this Annual Report on Form 10-K. 148 PART IV Item 15. Exhibits, Financial Statement Schedules The following documents are filed as part of this Annual Report on Form 10-K: (a) Financial Statements The information concerning our consolidated financial statements and Report of Independent Registered Public Accounting Firm required by this Item is incorporated by reference herein to the section of this Annual Report on Form 10-K in Item 8, entitled “Financial Statements and Supplementary Data.” (b) Financial Statement Schedules All schedules have been omitted because the required information is not present or not present in amounts sufficient to require submission of the schedules, or because the information required is included in the Financial Statements or notes thereto. (c) Exhibits The list of exhibits filed with this report is set forth in the Exhibit Index immediately preceding the signature page and is incorporated herein by reference. Exhibit Number Description of Document 2.1 Firm Intention Letter Agreement, dated May 20,2025, by and between ASP Isotopes Inc. and Renergen Limited (incorporated by reference to Exhibit 2.1 to the Form 8-K filed on May 20, 2025). 2.2 Letter Agreement, dated November 27, 2025, by and among ASP Isotopes Inc. and Renergen Limited (incorporated by reference to Exhibit 2.1 to the Form 8-K filed on November 28, 2025). 3.1 Amended and Restated Certificate of Incorporation (incorporated by reference to Exhibit 3.3 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)). 3.2 Amended and Restated Bylaws (incorporated by reference to Exhibit 3.2 to the Annual Report on Form 10-K for the year ended December 31, 2023, filed on April 10, 2024). 4.1 Description of Securities Registered Under Section 12 of the Securities Exchange Act of 1934 (incorporated by reference to Exhibit 4.1 to the Annual Report on Form 10-K for the year ended December 31, 2023, filed on April 10, 2024). 4.2 Common Stock Purchase Warrant dated March 17, 2023 (incorporated by reference to Exhibit 4.2 to the Annual Report on Form 10-K for the year ended December 31, 2023). 4.3 Placement Agent Common Stock Purchase Warrant dated March 17, 2023 (incorporated by reference to Exhibit 4.3 to the Annual Report on Form 10-K for the year ended December 31, 2023). 4.4 Warrant issued to Armistice Capital Master Fund Ltd. dated April 10, 2024 (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K filed with the SEC on April 9, 2024). 10.1+ ASP Isotopes Inc. 2021 Stock Incentive Plan, as amended, and form of award agreements thereunder (incorporated by reference to Exhibit 10.1 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)). 10.2+ ASP Isotopes Inc. 2022 Equity Incentive Plan and form of award agreements thereunder (incorporated by reference to Exhibit 10.2 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)) 10.3+ Performance Share Award Grant Notice and Performance Share Award Agreement with Paul Mann, dated October 4, 2021, as amended (incorporated by reference to Exhibit 10.3 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)). 10.4+ Form of Indemnification Agreement between the registrant and each of its directors and executive officers (incorporated by reference to Exhibit 10.4 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)). 10.5+ Form of Director Agreement (incorporated by reference to Exhibit 10.5 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)). 10.6+ Executive Employment Agreement by and between the registrant and Paul Mann, dated October 4, 2021 (incorporated by reference to Exhibit 10.6 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)). 149 10.7+ Executive Employment Agreement by and between ASP Isotopes Guernsey Limited and Hendrik Strydom, dated January 19, 2022 (incorporated by reference to Exhibit 10.7 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)). 10.8+ Executive Employment Agreement by and between ASP Isotopes Guernsey Limited and Robert Ainscow, dated October 4, 2021, as amended (incorporated by reference to Exhibit 10.8 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)). 10.9 Letter Agreements between the registrant and Dr Einar Ronander and Dr Hendrik Strydom, dated January 2021 (incorporated by reference to Exhibit 10.13 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)). 10.10 Chief Scientific Adviser Agreement between the registrant and Dr Einar Ronander, dated January 2021 (incorporated by reference to Exhibit 10.14 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)). 10.11 Lease for Molybdenum Processing Plant between ASP Isotopes South Africa (Proprietary) Limited (formerly PDS Photonica Holdings South Africa (Proprietary) Limited) and Morgan Creek Properties 311 Pty Ltd. (incorporated by reference to Exhibit 10.15 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)). 10.12 Form of Subscription Agreement (incorporated by reference to Exhibit 10.16 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)). 10.13 License Agreement between ASP Isotopes UK Ltd and Klydon (Proprietary) Limited dated July 26, 2022 (incorporated by reference to Exhibit 10.17 to the Form S-1/A filed on November 9, 2022 (File No. 333-267392)). 10.14 Amended Executive Employment Agreement between the registrant and Paul Mann effective December 20, 2022 (incorporated by reference to Exhibit 10.19 to the Annual Report on Form 10-K for the year ended December 31, 2023, filed on April 10, 2024). 10.15 Acknowledgement of Debt Agreement between ASP Isotopes South Africa (Proprietary) Limited and Klydon (Proprietary) Limited dated November 30, 2022 (incorporated by reference to Exhibit 10.20 to the Annual Report on Form 10-K for the year ended December 31, 2023, filed on April 10, 2024). 10.16 Deed of Security Agreement between ASP Isotopes South Africa (Proprietary) Limited and Klydon (Proprietary) Limited dated November 30, 2022 (incorporated by reference to Exhibit 10.21 to the Annual Report on Form 10-K for the year ended December 31, 2023, filed on April 10, 2024). 10.17 Securities Purchase Agreement dated March 14, 2023 (private placement of shares and warrants) (incorporated by reference to Exhibit 10.22 to the Annual Report on Form 10-K for the year ended December 31, 2023, filed on April 10, 2024). 10.18 Registration Rights Agreement dated March 14, 2023 (private placement of shares and warrants) (incorporated by reference to Exhibit 10.23 to the Annual Report on Form 10-K for the year ended December 31, 2023, filed on April 10, 2024). 10.19 Release Agreement, dated March 23, 2023 between Revere Securities LLC and ASP Isotopes Inc. (incorporated by reference to Exhibit 10.24 to the Annual Report on Form 10-K for the year ended December 31, 2023, filed on April 10, 2024) 10.20 Form of Securities Purchase Agreement by and between ASP Isotopes Inc. and the purchasers named therein (October 2023 private placement of shares) (incorporated by reference to Exhibit 10.1 to the Company’s Current Report on Form 8-K filed with the SEC on October 12, 2023). 10.21 Form of Registration Rights Agreement by and between ASP Isotopes Inc. and the purchasers named therein (October 2023 private placement of shares) (incorporated by reference to Exhibit 10.2 to the Company’s Current Report on Form 8-K filed with the SEC on October 12, 2023). 10.22 Share Purchase Agreement, dated October 30, 2023, by and between ASP Isotopes Inc., as purchaser, and Nucleonics Imaging Proprietary Limited, as seller, relating to the purchase and sale of ordinary shares of Pet Labs Pharmaceuticals Proprietary Limited (incorporated by reference to Exhibit 10.1 to the Company’s Current Report on Form 8-K filed with the SEC on October 30, 2023). 10.23 Convertible Note Purchase Agreement (including Form of Convertible Promissory QLE Note), dated as of February 29, 2024, by and among Quantum Leap Energy LLC and the Purchasers listed therein (incorporated by reference to Exhibit 10.1 to the Company’s Current Report on Form 8-K filed with the SEC on February 29, 2024). 150 10.24 Registration Rights Agreement, dated as of February 29, 2024, by and among Quantum Leap Energy LLC and the Purchasers listed therein (incorporated by reference to Exhibit 10.2 to the Company’s Current Report on Form 8-K filed with the SEC on February 29, 2024). 10.25+ Quantum Leap Energy LLC 2024 Equity Incentive Plan (incorporated by reference to Exhibit 10.3 to the Company’s Current Report on Form 8-K filed with the SEC on February 29, 2024). 10.26 Form of Warrant Inducement Agreement by and between ASP Isotopes Inc. and Armistice Capital Master Fund Ltd. (incorporated by reference to Exhibit 10.1 to the Company’s Current Report on Form 8-K filed with the SEC on April 9, 2024). 10.27 ASP Isotopes Inc. 2024 Inducement Equity Incentive Plan and forms of award agreement thereunder (incorporated by reference to Exhibit 10.1 to the Form 8-K filed on June 13, 2024). 10.28 Executive Employment Agreement by and between the Company and Heather Kiessling, dated June 10, 2024 (incorporated by reference to Exhibit 10.1 to the Form 10-Q filed on November 19, 2024). 10.29 Convertible Note Purchase Agreement (including Form of Convertible Promissory QLE Note), dated as of June 5, 2024, by and among Quantum Leap Energy LLC and the Purchasers listed therein (incorporated by reference to Exhibit 10.1 to the Form 8-K filed on June 6, 2024). 10.30 Registration Rights Agreement, dated as of June 5, 2024, by and among Quantum Leap Energy LLC and the Purchasers listed therein (incorporated by reference to Exhibit 10.2 to the Form 8-K filed on June 6, 2024). 10.31 + Non-Employee Director Compensation Policy adopted effective October 30, 2024 (incorporated by reference to Exhibit 10.31 to the Form 10-K filed on March 31, 2025). 10.32 Loan Agreement, dated May 19, 2025, by and among ASP Isotopes Inc., ASP Isotopes South Africa Proprietary Limited, as lender, and Renergen Limited, as borrower (incorporated by reference to Exhibit 10.1 to the Form 8-K filed on May 20, 2025). 10.33 Loan Agreement, dated May 16, 2025, by and between QLE TP Funding SPE LLC, as borrower, and TerraPower, LLC, as lender (incorporated by reference to Exhibit 10.1 to the Form 8-K filed on May 22, 2025). 10.34 + ASP Isotopes Inc. 2025 Inducement Equity Incentive Plan and forms of award agreement thereunder (incorporated by reference to Exhibit 10.1 to the Form 10-Q filed on August 14, 2025). 10.35 Natrium Project Procurement Terms and Conditions – Enrichment Services by and between TerraPower, LLC and ASP Isotopes Inc., dated as of May 16, 2025 (incorporated by reference to Exhibit 10.3 to the Form 10-Q filed on August 14, 2025). 10.36 HALEU Long-Term Supply Agreement by and between TerraPower, LLC and ASP Isotopes Inc., dated as of May 16, 2025 (incorporated by reference to Exhibit 10.4 to the Form 10-Q filed on August 14, 2025). 10.37 Form of Convertible Note Purchase Agreement (including Form of Convertible Promissory QLE Note), by and among Quantum Leap Energy LLC and the Purchasers party thereto (incorporated by reference to Exhibit 10.1 to the Form 8-K filed on November 14, 2025). 10.38 Form of Registration Rights Agreement, by and among Quantum Leap Energy LLC and the Investors party thereto (incorporated by reference to Exhibit 10.2 to the Form 8-K filed on November 14, 2025). 10.39 Letter to the Term Loan Facility Agreement, dated November 27, 2025, by and among ASP Isotopes Inc., ASP Isotopes South Africa Proprietary Limited, as lender, and Renergen Limited, as borrower (incorporated by reference to Exhibit 10.1 to the Form 8-K filed on November 28, 2025). 10.40 * Loan Agreement, between Industrial Development Corporation of South Africa Limited and Tetra4 Proprietary Limited, dated December 20, 2021. 10.41 * Amendment, dated October 10, 2023, to Loan Agreement between Industrial Development Corporation of South Africa Limited and Tetra4 Proprietary Limited. 10.42 * Amendment, dated September 1, 2025, to Loan Agreement between Industrial Development Corporation of South Africa Limited and Tetra4 Proprietary Limited. 10.43 * Finance Agreement, between U.S. International Development Finance Corporation, as successor in interest to Overseas Private Investment Corporation, and Tetra4 Proprietary Limited, dated August 20, 2019. 151 10.44 * Amendment No. 1 to Finance Agreement, between United States. International Development Finance Corporation and Tetra4 Proprietary Limited, dated March 30, 2020. 10.45 * Amendment No. 2 to Finance Agreement, between United States. International Development Finance Corporation and Tetra4 Proprietary Limited, dated April 28, 2020. 10.46 * Amendment No. 3 to Finance Agreement, between United States. International Development Finance Corporation and Tetra4 Proprietary Limited, dated February 26, 2021. 10.47 * Amendment No. 4 to Finance Agreement, between United States. International Development Finance Corporation and Tetra4 Proprietary Limited, dated August 24, 2021. 10.48 * Amendment No. 5 to Finance Agreement, between United States. International Development Finance Corporation and Tetra4 Proprietary Limited, dated December 16, 2021. 10.49 * Amended And Restated Secured Term Loan Facility Agreement between Renergen Limited and the Standard Bank of South Africa Limited, dated December 12, 2025. 10.50 Series Seed-1 Preferred Stock Purchase Agreement, dated as of July 28, 2025, by and between IsoBio, Inc. and ASP Isotopes Inc. (incorporated by reference to Exhibit 10.1 to the Form 10-Q filed on November 19, 2025). 10.51 Investors’ Rights Agreement, dated as of July 28, 2025, by and among IsoBio, Inc. and the Investors named therein (incorporated by reference to Exhibit 10.2 to the Form 10-Q filed on November 19, 2025). 10.52 Voting Agreement, dated as of July 28, 2025, by and among IsoBio, Inc., ASP Isotopes Inc. and the Key Holders named therein (incorporated by reference to Exhibit 10.3 to the Form 10-Q filed on November 19, 2025). 10.53 Right of First Refusal and Co-Sale Agreement, dated as of July 28, 2025, by and among IsoBio, Inc. ASP Isotopes Inc. and the Key Holders named therein (incorporated by reference to Exhibit 10.4 to the Form 10-Q filed on November 19, 2025). 10.54 *+ Second Amendment to Executive Employment Agreement between the registrant and Paul Mann dated April 5, 2024. 19.1 * Insider Trading Policy. 21.1 * List of Subsidiaries of the Registrant 23.1 * Consent of EisnerAmper LLP, independent registered public accounting firm. 24.1 * Power of Attorney (included as part of the signature page to this report). 31.1 * Certification of Principal Executive Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. 31.2 * Certification of Principal Accounting Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. 32.1 ** Certification of Principal Executive Officer and Financial Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. 97.1 Policy Relating to Recovery of Erroneously Awarded Compensation, effective October 2, 2023 2023 (incorporated by reference to Exhibit 97.1 to the Form 10-K filed on April 10, 2024). 99.1 License Agreement, dated as of February 16, 2024, among ASP Isotopes UK Limited, as licensor, and Quantum Leap Energy LLC and Quantum Leap Energy Limited, as licensee (incorporated by reference to Exhibit 99.4 to the Form 8-K filed on February 29, 2024). 99.2 EPC Services Framework Agreement, dated as of February 16, 2024, between ASP Isotopes Inc. and Quantum Leap Energy LLC (incorporated by reference to Exhibit 99.5 to the Form 8-K filed on February 29, 2024). 101.INS Inline XBRL Instance Document - the instance document does not appear in the Interactive Data File because XBRL tags are embedded within the Inline XBRL document 101.SCH Inline XBRL Taxonomy Extension Schema With Embedded Linkbase Documents 104 Cover Page Interactive Data File (embedded within the Inline XBRL document) * Filed herewith. 152 ** Furnished herewith. + Management contract or compensatory plan or arrangement. Item 16. Form 10-K Summary None. 153 SIGNATURES Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized, on the 10th day of April, 2026. ASP Isotopes Inc. By /s/ PAUL E. MANN Paul E. Mann Executive Chairman, Chief Executive Officer and Director We, the undersigned directors and officers of ASP Isotopes Inc., hereby severally constitute Paul E. Mann and Heather Kiessling, and each of them singly, as our true and lawful attorneys with full power to each of them to sign for us, in our names in the capacities indicated below, any and all amendments to this Annual Report on Form 10-K filed with the Securities and Exchange Commission. This power of attorney may only be revoked by a written document executed by the undersigned that expressly revokes this power by referring to the date and subject hereof. Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant in the capacities and on the dates indicated. Signature Title Date /s/ PAUL E. MANN Chief Executive Officer, Executive Chairman and Director (Principal Executive Officer) April 10, 2026 Paul E. Mann /s/ HEATHER KIESSLING Chief Financial Officer (Principal Financial and Accounting Officer) April 10, 2026 Heather Kiessling /s/ MICHAEL GORLEY, Ph.D. Director April 10, 2026 Michael Gorley, Ph.D. /s/ RALPH L. HUNTER, Jr. Director April 10, 2026 Ralph L Hunter, Jr. /s/ SIPHO N. MASEKO Director April 10, 2026 Sipho N. Maseko /s/ DUNCAN MOORE, Ph.D. Director April 10, 2026 Duncan Moore, Ph.D. /s/ ROBERT RYAN Director April 10, 2026 Robert Ryan /s/ TODD WIDER, M.D. Director April 10, 2026 Todd Wider, M.D. 154