Sec Form 4 Filing - Webster Stephen @ LUXFER HOLDINGS PLC - 2024-03-20

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) 03/20/2024 (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 03/20/2024 M 750 A 19,261 ( 2 ) D Ordinary Shares 03/20/2024 M 127 A 19,388 D Ordinary Shares 03/20/2024 M 1,000 A 20,388 D Ordinary Shares 03/20/2024 M 78 A 20,466 D Ordinary Shares 03/20/2024 M 800 A 21,266 D Ordinary Shares 03/20/2024 M 87 A 21,353 D Ordinary Shares 03/20/2024 M 1,070 A 22,423 D Ordinary Shares 03/20/2024 M 51 A 22,474 D Ordinary Shares 03/20/2024 F 2,043 D $ 10.67 20,431 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 ) 03/20/2024 M 750 ( 3 ) 03/13/2026 Ordinary Shares 750 ( 1 ) 0 D Dividend Equivalent Rights ( 4 ) 03/20/2024 M 127 ( 4 ) 03/13/2026 Ordinary Shares 127 ( 4 ) 0 D Stock Options (Right to Buy) ( 1 ) 03/20/2024 M 1,000 ( 5 ) 03/14/2028 Ordinary Shares 1,000 ( 1 ) 2,000 D Dividend Equivalent Rights ( 4 ) 03/20/2024 M 78 ( 4 ) 03/14/2028 Ordinary Shares 78 ( 4 ) 165 D Stock Options (Right to Buy) ( 1 ) 03/20/2024 M 800 ( 6 ) 03/15/2027 Ordinary Shares 800 ( 1 ) 800 D Dividend Equivalent Rights ( 4 ) 03/20/2024 M 87 ( 4 ) 03/15/2027 Ordinary Shares 87 ( 4 ) 92 D Stock Options (Right to Buy) ( 1 ) 03/20/2024 M 1,070 ( 7 ) 03/20/2029 Ordinary Shares 1,070 ( 1 ) 3,210 D Dividend Equivalent Rights ( 4 ) 03/20/2024 M 51 ( 4 ) 03/20/2029 Ordinary Shares 51 ( 4 ) 160 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/ Megan E. Glise under Power of Attorney for Stephen Webster 03/21/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )1 for 1, subject to a nominal payment of $1.00 per Ordinary Share. ( 2 )The above figure includes (i) 231 Ordinary Shares, including those accrued related to dividend reinvestment rights, acquired pursuant to the Luxfer Holdings PLC Share Incentive Plan for the purchase period of June 1, 2023 - December 31, 2023; and (ii) 255 Ordinary Shares acquired since the Reporting Person's last reportable transaction pursuant to dividend reinvestment transactions. ( 3 )Represents the exercise of time-based Stock Options awarded on March 13, 2020. The subject Stock Options fully vested and were exercisable as of March 13, 2024. ( 4 )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. ( 5 )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, 2024. The remaining Stock Options vest and become exercisable in two equal annual installments on March 14, 2025 and March 14, 2026. ( 6 )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, 2024. The remaining Stock Options vest and become exercisable on March 15, 2025. ( 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, 2024. The remaining Stock Options vest in three equal annual installments beginning on March 20, 2025.

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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