Proxy Results, Corporate Action, Amendments to Bylaws (Form 8-K)

Item 3.03 Material Modification to Rights of Security Holders.

To the extent required by Item 3.03 of Form 8-K, the information contained in Item 5.03 of this Current Report on Form 8-K is incorporated herein by reference.

Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.

On December 15, 2025, 374Water Inc. ("374Water" or the "Company") filed a Certificate of Amendment of the Amended and Restated Certificate of Incorporation (the "Certificate of Amendment") with the Secretary of State of the State of Delaware to effect a 1-for-10 reverse stock split (the "Reverse Stock Split") of the issued and outstanding shares of the Company's Common Stock (the "Common Stock" ). The Certificate of Amendment will take effect as of 12:01 a.m. Eastern Time on December 26, 2025 (the "Effective Time").

Upon the Effective Time of the Certificate of Amendment with the Secretary of State of the State of Delaware, each ten (10) shares of Common Stock issued immediately prior to the Effective Time shall, automatically and without any action on the part of the respective holders thereof, be reclassified and combined into one (1) share of Common Stock. No fractional shares shall be issued. In lieu thereof, stockholders of record who otherwise would be entitled to receive fractional shares will be instead entitled to an amount in cash (without interest or deduction) equal to the fraction of one share to which such stockholder would otherwise be entitled, multiplied by the closing price of our common stock on Nasdaq on the date of the Effective Time. Except for the right to receive the cash payment in lieu of fractional shares, stockholders will not have any voting, dividend or other rights with respect to the fractional shares they would otherwise be entitled to receive. The cash payment may be paid by check, wire, deposit into an existing brokerage account or some other means depending on how the shares are held.. The Reverse Stock Split will affect all shares of the Company's Common Stock outstanding, or held as treasury stock, immediately prior to the effective time of the Reverse Stock Split, as well as the number of shares of Common Stock available for issuance under the Company's equity incentive plans. In addition, the Reverse Stock Split will result in a reduction in the number of shares of Common Stock issuable upon the exercise of stock options, restricted stock units and warrants outstanding immediately prior to the effectiveness of the Reverse Stock Split with a corresponding increase in the exercise price per share applicable to such stock options. The total number of shares of capital stock that we are authorized to issue pursuant to the Company's Amended and Restated Certificate of Incorporation will not be affected by the Reverse Stock Split and will remain at 1,050,000,000 shares, consisting of 1,000,000,000 shares of common stock and 50,000,000 shares of preferred stock.

The Company's Common Stock is scheduled to begin trading on a post-Reverse Stock Split basis at the market open on December 26, 2025, under the Company's existing trading symbol "SCWO." The new CUSIP number for the Common Stock following the Reverse Stock Split is 88583P 203. The par value per share of the common stock will remain unchanged at $0.0001.

The foregoing brief description of the Certificate of Amendment is qualified in its entirety by the full text of the Certificate of Amendment, filed as Exhibit 3.1 hereto and incorporated herein by reference.

Item 5.07 Submission of Matters to a Vote of Security Holders.

At a special meeting of stockholders (the "Special Meeting") of 374Water held on December 15, 2025, the following proposals were submitted to the stockholders of 374Water:

At the close of business on October 24, 2025, the record date for the Special Meeting, 169,248,799 shares of the Company's common stock, par value $0.0001 per share, were issued and outstanding and entitled to vote at the Special Meeting.

The number of votes cast for, against and abstaining in respect of the Reverse Stock Split Proposal is set forth below:

Since there were sufficient votes at the time of the Special Meeting to approve the Reverse Stock Split Proposal, the Adjournment Proposal was not called for at the Special Meeting.