Russell Kline - 09 Oct 2025 Form 4 Insider Report for 374Water Inc. (SCWO)

Role: Chief Financial Officer
Signature: /s/ Russell Kline
Issuer symbol: SCWO
Transactions as of: 09 Oct 2025
Net transactions value: $0
Form type: 4
Filing time: 14 Oct 2025, 17:00:28 UTC
Previous filing: 02 Sep 2025
Next filing: 18 Dec 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Russell Kline	Chief Financial Officer	C/O 374 WATER INC., 100 SOUTHCENTER COURT SUITE 200, MORRISVILLE	/s/ Russell Kline	14 Oct 2025	0002049257

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	SCWO	Stock options (right to buy)	Award	$0	+500,000	+162%	$0.000000	808,642	09 Oct 2025	Common Stock	500,000	$0.6000	Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	. Represents stock options granted to the Reporting Person as a special retention incentive award in connection with his continued service as Chief Financial Officer of 374Water Inc. (the "Company"). 50% of the stock options vest and become exercisable on the first anniversary of the grant date and the remaining 50% of the stock options vest and become exercisable on the second anniversary of the grant date, subject to the Reporting Person's continuous service through each vesting date. In the event of an involuntary termination of the Reporting Person without cause, all remaining unvested stock options will vest and become exercisable immediately. Upon vesting, each stock option gives the Reporting Person the right to purchase one share of the Company's Common Stock at the exercise price. The stock options expire on the date which is ten years from the grant date, unless earlier terminated in accordance with the stock option grant agreement.

Content

. Represents stock options granted to the Reporting Person as a special retention incentive award in connection with his continued service as Chief Financial Officer of 374Water Inc. (the "Company"). 50% of the stock options vest and become exercisable on the first anniversary of the grant date and the remaining 50% of the stock options vest and become exercisable on the second anniversary of the grant date, subject to the Reporting Person's continuous service through each vesting date. In the event of an involuntary termination of the Reporting Person without cause, all remaining unvested stock options will vest and become exercisable immediately. Upon vesting, each stock option gives the Reporting Person the right to purchase one share of the Company's Common Stock at the exercise price. The stock options expire on the date which is ten years from the grant date, unless earlier terminated in accordance with the stock option grant agreement.