Sec Form 4 Filing - Webster Stephen @ LUXFER HOLDINGS PLC - 2025-06-09

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Webster Stephen 2. Issuer Name and Ticker or Trading Symbol LUXFER HOLDINGS PLC [ LXFR] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chief Financial Officer (Last) (First) (Middle) LUXFER HOLDINGS PLC, LUMNS LANE 3. Date of Earliest Transaction (MM/DD/YY) 06/09/2025 (Street) MANCHESTER, X0M27 8LN 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Ordinary Shares 06/09/2025 M 800 A 23,422 D Ordinary Shares 06/09/2025 M 128 A 23,550 D Ordinary Shares 06/09/2025 M 1,000 A 24,550 D Ordinary Shares 06/09/2025 M 125 A 24,675 D Ordinary Shares 06/09/2025 M 2,304 A 26,979 D Ordinary Shares 06/09/2025 M 900 A 27,879 D Ordinary Shares 06/09/2025 M 1,070 A 28,949 D Ordinary Shares 06/09/2025 M 92 A 29,041 D Ordinary Shares 06/09/2025 M 1,790 A 30,831 D Ordinary Shares 06/09/2025 M 75 A 30,906 D Ordinary Shares 06/09/2025 S 4,244 D $ 11.83 26,662 D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Stock Options (Right to Buy) ( 1 ) 06/09/2025 M 800 ( 3 ) 03/15/2027 Ordinary Shares 800 ( 1 ) 0 D Dividend Equivalent Rights ( 2 ) 06/09/2025 M 128 ( 2 ) 03/15/2027 Ordinary Shares 128 ( 2 ) 0 D Stock Options (Right to Buy) ( 1 ) 06/09/2025 M 1,000 ( 4 ) 03/14/2028 Ordinary Shares 1,000 ( 1 ) 1,000 D Dividend Equivalent Rights ( 2 ) 06/09/2025 M 125 ( 2 ) 03/14/2028 Ordinary Shares 125 ( 2 ) 144 D Stock Options (Right to Buy) ( 1 ) 06/09/2025 M 2,304 ( 5 ) 03/14/2027 Ordinary Shares 2,304 ( 1 ) 0 D Stock Options (Right to Buy) ( 1 ) 06/09/2025 M 900 ( 6 ) 03/14/2027 Ordinary Shares 900 ( 1 ) 0 D Stock Options (Right to Buy) ( 1 ) 06/09/2025 M 1,070 ( 7 ) 03/20/2029 Ordinary Shares 1,070 ( 1 ) 2,140 D Dividend Equivalent Rights ( 2 ) 06/09/2025 M 92 ( 2 ) 03/20/2029 Ordinary Shares 92 ( 2 ) 236 D Stock Options (Right to Buy) ( 1 ) 06/09/2025 M 1,790 ( 8 ) 03/18/2030 Ordinary Shares 1,790 ( 1 ) 5,370 D Dividend Equivalent Rights ( 2 ) 06/09/2025 M 75 ( 2 ) 03/18/2030 Ordinary Shares 75 ( 2 ) 230 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Webster Stephen LUXFER HOLDINGS PLC LUMNS LANE MANCHESTER, X0M27 8LN Chief Financial Officer Signatures /s/ Benjamin Coulson under Power of Attorney for Stephen Webster 06/11/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )1 for 1, subject to a nominal payment of $1.00 per Ordinary Share. ( 2 )Represents dividend equivalent rights accrued on employee Stock Options, which become exercisable proportionately with the Stock Options to which they relate. Each dividend equivalent right is the economic equivalent of one Ordinary Share. The subject dividend equivalent rights convert 1 for 1, subject to a nominal payment of $1.00 per Ordinary Share. ( 3 )Represents the exercise of time-based Stock Options awarded on March 15, 2021. The subject Stock Options vested and were exercisable as of March 15, 2025. ( 4 )Represents the exercise of time-based Stock Options awarded on March 14, 2022. The subject Stock Options vested and were exercisable as of March 14, 2025. The remaining Stock Options vest and become exercisable on March 14, 2026. ( 5 )Represents the exercise of performance-based Stock Options (at 96% target) awarded on March 14, 2022. 100% of the performance-based Stock Options vested on March 14, 2025 upon the achievement of Earnings Per Share (EPS) Growth goals for the three-year performance period ended December 31, 2024. ( 6 )Represents the exercise of performance-based Stock Options (at 25% target) awarded on March 14, 2022. 100% of the performance-based Stock Options vested on March 14, 2025 upon the achievement of Total Shareholder Return (TSR) goals for the three-year performance period ended December 31, 2024. ( 7 )Represents the exercise of time-based Stock Options awarded on March 20, 2023. The subject Stock Options vested and were exercisable as of March 20, 2025. The remaining Stock Options vest in two equal annual instalments beginning on March 20, 2026 ( 8 )Represents the exercise of time-based Stock Options awarded on March 18, 2024. The subject Stock Options vested and were exercisable as of March 18, 2025. The remaining Stock Options vest in three equal annual instalments beginning on March 18, 2026.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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