9. Debt

Credit facility and term loans contain a repayment on demand clause. Management believes the carrying values of debt outstanding approximates fair value based on the interest rates and scheduled maturities applicable to the outstanding borrowings.

Promissory Note Payable

In August 2025, the Company executed a promissory note payable with a finance company to fund a general liability insurance policy for $0.2 million. This note bears interest at an annual rate of 10.0% with twelve monthly payments beginning in August 2025. As of March 31, 2026 and December 31, 2025, this promissory note payable balance was $0.1 million.

The Company assumed a promissory note in connection with the acquisition of Renergen in January 2026 to fund a general liability insurance policy for approximately $1.1 million. This note bears interest at an annual rate of 9.6% with eleven monthly payments beginning in December 2025. As of March 31, 2026, this promissory note payable balance was $0.7 million.

Motor Vehicle and Equipment Loans

Periodically, the Company enters into loans to purchase motor vehicles and certain equipment. For the three months ended March 31, 2026, the Company entered into new loans totaling $0.1 million. These loans are secured by the underlying assets included in property and equipment. The loans have variable interest rates ranging from 9.25% to 11.25% and mature from September 2028 to February 2031. Minimum monthly payments total $55,000. For each of the three months ended March 31, 2026 and 2025, interest expense under the outstanding loans was $0.1 million. As of March 31, 2026 and December 31, 2025, motor vehicle and equipment loans totaled $2.1 million and $1.9 million, respectively.

Credit Facilities

Renergen's subsidiary Tetra4 entered into a $40.0 million finance agreement with the U.S. International Development Finance Corporation ("DFC"), as successor and assignee of the Overseas Private Investment Corporation ("DFC Credit Facility") on August 20, 2019 (as amended, the “Facility Agreement”). Drawdowns occurred between September 2019 and September 2021. Tetra4 is obligated to repay the loan in equal quarterly installments of $1.1 million on each payment date which began on August 2022 and will end on August 15, 2031. The drawdowns bear interest at rates ranging from 1.24% to 2.11% per annum. The DFC Credit Facility is secured by a pledge of Tetra4’s assets, land and the restricted cash accounts disclosed in Note 2. For the period January 6, 2026 through March 31, 2026, interest expense under the DFC Credit Facility was $0.3 million. As of March 31, 2026, the outstanding principal amount of the DFC Credit Facility totaled $24.0 million.

Secured Term Loans

Renergen's subsidiary Tetra4 entered into a ZAR 160.7 million loan agreement (the “IDC Loan Agreement”) with the Industrial Development Corporation of South Africa Limited (“IDC”), as lender, on December 20, 2021 ("IDC Loan"). A drawdown occurred in December 2021 and is repayable in 102 equal monthly payments which commenced in July 2023. The loan terms included a 12-month interest capitalization and an 18-month capital repayment moratorium. The loan accrues interest at the prime lending rate plus 3.5% and is secured by a pledge of Tetra4’s assets, land and the restricted cash disclosed in Note 3. The following financial covenants apply to the IDC Loan: Tetra4 is required to maintain (a) a ratio of all interest bearing Debt to EBITDA of not more than 3.0 to 1; (b) a ratio of Current Assets to Current Liabilities of not less than 1 to 1; (c) a ratio of Cash Flow for the most recently completed four (4) consecutive full fiscal quarters, taken as a single accounting period, to Debt Service for the most recently completed four (4) consecutive full fiscal quarters, taken as a single accounting period, of not less than 1.30 to 1; (d) a ratio of Cash Flow for the most recently completed four (4) fiscal quarters, taken as a single accounting period, to Debt Service for the next succeeding four (4) consecutive full fiscal quarters of not less than 1.3 to 1; and (e) at all times, a Reserve Tail Ratio of not less than 25%.These financial covenants will be measured by Tetra4 on each Calculation Date. Additionally, at all times (f) Tetra4 is required to ensure that the DSRA is funded in an amount equal to, on any given date, a Rand amount equal to the aggregate amount of the sum of all payments of principal, interest and fees made or required to be made by Tetra4 under the IDC Loan Agreement for the immediately succeeding six-month period, to be used as a payment buffer for Tetra4’s repayment obligations under and in terms of the IDC Loan Agreement. The IDC Loan Agreement contains negative covenants, which include that Tetra4 shall not make any shareholder dividend distribution, repay any shareholders’ loans and/or pay any interest on shareholders’ loans or make any payments whatsoever to its shareholders without the IDC’s prior written consent if (i) Tetra4 is in breach of any term of the IDC Loan Agreement; or (ii) the making of such payment would result in a breach of any one or more of the financial ratios described above. As of March 31, 2026, Tetra4 was not in compliance with the covenants described in clauses (a)-(d) above which were scheduled to take effect on February 15, 2026 (the most recent Calculation Date). Tetra4 is actively

engaged with IDC to amend the IDC Loan Agreement to defer the Calculation Date for covenant measurement to October 31, 2026. Although no assurance can be provided, the Company expects to receive a waiver from IDC in connection with the renegotiation of the applicable Calculation Date. The IDC Loan outstanding on March 31, 2026 amounted to ZAR 144.1 million ($8.4 million) and interest expense for the period January 6, 2026 through March 31, 2026 amounted to ZAR 4.8 million ($0.3 million). Qualifying interest attributable to assets under construction is capitalized. All capitalized terms used in this paragraph but not defined herein have the meaning ascribed to them in the IDC Loan Agreement.

Pursuant to a Secured Term Loan Facility Agreement, Renergen obtained a ZAR 155.0 million secured loan from Standard Bank of South Africa ("SBSA") on August 30, 2024. Such Secured Term Loan Facility Agreement was subsequently amended and restated on December 12, 2025 (as amended, the “SBSA Loan”). The drawdowns occurred between August 2024 and October 2024. The SBSA Loan accrues compounded interest at a rate linked to the three-month Johannesburg Interbank Average Rate plus a variable margin (21.725% as of March 31, 2026). The SBSA Loan was scheduled to mature on the repayment date of March 31, 2026. The Company is currently engaged with SBSA and is in the process of finalizing an amendment to the SBSA Loan to extend the repayment date to no earlier than May 31, 2026, or such later date as may be mutually agreed between the parties. Although no assurance can be provided, discussions are ongoing and the Company expects the amendment to be completed in the ordinary course. Until such amendment is executed, the existing terms of the SBSA Loan remain in effect. The SBSA Loan is secured by a third ranking pledge of Tetra4’s assets and shares held by Renergen in Tetra4. In addition, NTIGT Investment Proprietary Limited (“NTIGT”), an affiliate of Mr. Nicholas Mitchell and Mr. Stefano Marani, has entered into cession and pledge agreement with SBSA, pursuant to which NTIGT has pledged and ceded as security, which remain in NTIGT’s possession unless called, collectively 1,546,268 shares of ASP Isotopes common stock issued to Mr. Nicholas Michell and Mr. Stefano Marani in exchange for their shares of Renergern prior to the acquisition by ASP Isotopes, to and in favor of SBSA. The Molopo litigation discussed below and the need to procure the requisite equity injection by January 24, 2025 resulted in events of default with respect to the SBSA Loan. SBSA provided a waiver for both default events. To date, no further remedies have been requested by SBSA due to the progress achieved in securing funding for Renergen’s LNG plant in the Free State, South Africa. The SBSA Loan outstanding on March 31, 2026 amounted to ZAR 213.4 million ($12.5 million) and interest expense for the period January 6, 2026 through March 31, 2026 amounted to ZAR 10.1 million ($0.6 million).

Unsecured Term Loans

Renergen entered into a $7.0 million unsecured convertible debenture subscription agreement ("Subscription Agreement") with AIRSOL, an Italian wholly-owned subsidiary of SOL S.p.A., on August 30, 2023. The Subscription Agreement provided for two tranches of funding: $3.0 million (“Tranche 1”), received on August 30, 2023, and $4.0 million (“Tranche 2”), received on March 18, 2024. The debentures include a contractual maturity date, initially set at February 28, 2025 and amended by agreement to August 31, 2025, subject to the terms of the Subscription Agreement (as amended) and the related Helium Sale and Purchase Agreement. The debentures accrue interest at 13% per annum, calculated and compounded semi-annually, with interest payable on February 28 and August 31 each year. The contractual maturity date has passed and the liability remains outstanding as a result of a dispute between the parties in respect of repayment, and arbitration proceedings have commenced and are currently ongoing. No additional amendments to the Subscription Agreement were made during the reporting period.. The carrying amount of the debentures outstanding at March 31, 2026 was $7.1 million.

Renergen's subsidiary Tetra4 entered into a ZAR 50.0 million loan agreement with Molopo on April 11, 2014. The loan term was for a period of 10 years and six months commencing on July 1, 2014 (repayable on August 31, 2024). During this period the loan was unsecured and is interest free. The loan was discounted on initial recognition and the unwinding of the discount applied on initial recognition was recognized in borrowing costs as imputed interest.

As the loan was not repaid on August 31, 2024 it now accrues interest at the prime lending rate plus 2% (12.25% on March 31, 2026). The loan can only be repaid when Tetra4 declares a dividend and utilizes a maximum of 36% of the distributable profits in order to pay the dividend. It is not expected that the loan or interest will be repaid in the next 12 months given the unavailability of distributable profits based on Tetra4’s most recent forecasts. As such, the loan is classified as noncurrent. Interest expense was ZAR 1.6 million for the three months ended March 31, 2026 ($0.1 million). The Molopo loan outstanding on March 31, 2026 amounted to ZAR 60.5 million ($3.5 million).

In November 2024, Molopo initiated legal proceedings against Tetra4 in the High Court of South Africa, Gauteng Local Division, Johannesburg, by issuing a summons alleging a breach of contract when Renergen sold the 5.5% stake in Tetra4 to Mahlako Gas Energy Proprietary Limited ("MGE"). The claim pertains to a written loan agreement entered into between Molopo, as the lender, and Tetra4, as the borrower, in April 2014 (as described above). As a consequence, Molopo has purported to cancel the loan agreement, which cancellation is disputed by Tetra4 on the basis that the investment by MGE did not constitute a payment by Tetra4 to its parent in the sale. According to the Lead Times Bulletin for the High Court in Gauteng, the earliest available hearing date is estimated to be approximately December 2030, hence the loan continues to be classified as noncurrent.

Convertible Notes Payable

In March 2024, QLE issued convertible notes payable (“March 2024 Convertible Notes”) totaling $21.1 million and received aggregate cash of $20.6 million. One of the notes totaling $0.5 million was issued to the placement agent in lieu of cash issuance costs.

In June 2024, QLE issued additional convertible notes payable (“June 2024 Convertible Notes”) totaling $5.5 million and received aggregate cash of $5.4 million. One of the notes totaling $0.1 million was issued to the placement agent in lieu of cash issuance costs Issuance costs paid in cash were negligible. The March 2024 Convertible Notes and the June 2024 Convertible Notes are collectively the “2024 Convertible Notes”.

The 2024 Convertible Notes were payable on demand in March 2029 and bear interest at an annual rate of 6% through March 7, 2025 and 8% thereafter. Upon a qualified financing event, the 2024 Convertible Notes convert into the shares issued in that qualified financing event at a price per share equal to 80% of the share price issued subject to a valuation cap. Upon a qualified transaction, the noteholders may elect to receive either 1.5x the principal and accrued interest balance in cash or convert into common shares.

The 2024 Convertible Notes were recorded on the consolidated balance sheet at their fair values. The fair value of the March 2024 Convertible Notes on the date of issuance was $21.1 million. The fair value of the June 2024 Convertible Notes on the date of issuance was $5.5 million. The fair value of the 2024 Convertible Notes as of March 31, 2025 was determined to be $34.4 million and the resultant change in fair value of $1.0 million was recorded in other income and expense in the condensed consolidated statement of operations and comprehensive loss for the three months ended March 31, 2025. In connection with the issuance of the 2025 Convertible Notes, QLE’s outstanding 2024 Convertible Notes originally issued in March 2024 and June 2024 automatically converted into 2025 Convertible Notes with a fair value of $147.7 million.

In November 2025, QLE issued convertible notes payable (“2025 Convertible Notes”) totaling $72.2 million and received aggregate cash of $69.6 million. The maturity date of the 2025 Convertible Notes is November 19, 2030. The 2025 Convertible Notes automatically convert into common shares upon QLE’s closing of an IPO or other qualifying public transaction at 80% of the share price, taking into consideration a valuation cap. QLE received $10.0 million in gross proceeds from American Ventures LLC, Series IX Quantum Leap and $30.0 million in gross proceeds from ASP Isotopes, its parent. Issuance costs paid in cash totaling $2.6 million were expensed in selling, general and administrative costs in the consolidated statement of operations and comprehensive loss for the year ended December 31, 2025.

The 2025 Convertible Notes are recorded on the consolidated balance sheet at their fair values. The fair value of the 2025 Convertible Notes as of March 31, 2026 and December 31, 2025 has been determined to be $199.9 million and $199.3 million, respectively. The resultant change in fair value of the 2025 Convertible Notes for the three months ended March 31, 2026 was $0.6 million, and has been recorded in other income and expense in the consolidated statement of operations and comprehensive loss. As of March 31, 2026, the total principal and accrued interest of the 2025 Convertible Notes is $226.2 million of which $6.4 million is from the interest.

The Company announced plans to list QLE as a standalone public company in the second half of 2025. The Company has also announced QLE and certain of its subsidiaries have entered into a loan agreement with TerraPower (the “TerraPower Loan Agreement”), a US nuclear innovation company, for a multiple advance term loan of up to $22.0 million related to financing support for the construction of a new uranium enrichment facility capable of producing HALEU in South Africa. Per the terms of the TerraPower Loan Agreement and subject to the satisfaction of various conditions precedent to each disbursement (including receiving all required licenses and permits to perform uranium enrichment in South Africa), the borrower could receive aggregate loan disbursements of $20.0 million.

American Ventures Advisory Agreement

On October 28, 2025, QLE entered into an Advisory Agreement (“Advisory Agreement”) with American Ventures LLC, a Delaware limited liability company (“American Ventures”). Under the Advisory Agreement, American Ventures will provide various services to the Company related to QLE and its present and future subsidiaries’ business and operations and is considered a related party based on its 2025 Convertible Notes holdings.

In October 2025, pursuant to the Advisory Agreement, QLE issued RSUs representing a right to receive a number of units or shares of common equity of QLE equal to 4.0% of the common equity of QLE deemed outstanding as of the date of grant, treating as outstanding only (i) ASP Isotopes’ membership interest in the Company and (ii) the shares or units of common equity issuable upon conversion of the 2024 Convertible Notes (or any securities issued upon conversion or exchange thereof). The total number of such RSUs cannot yet be calculated because the precise number of these units is based on a percentage of common equity deemed outstanding, which is contingent, in part, on the amount of securities issuable upon the conversion of certain of QLE’s 2025 Convertible Notes that were issued upon conversion of certain 2024 Convertible Notes. Such RSUs will vest as follows: (x) 50% upon the completion of the listing event, provided that such listing event occurs within 24 months of October 28, 2025, and (y) 50% on the six-month anniversary of such listing event.