Sec Form 5 Filing - LAWDAY MARK JAMES @ LUXFER HOLDINGS PLC - 2023-12-31

FORM 5 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 LAWDAY MARK JAMES 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) See Remarks (Last) (First) (Middle) LUXFER HOLDINGS PLC, LUMNS LANE 3. Date of Earliest Transaction (MM/DD/YY) 12/31/2023 (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 05/08/2023 M( 1 ) 750 A 2,648 D Ordinary Shares 05/08/2023 M( 1 ) 181 A 2,829 D Ordinary Shares 05/08/2023 M( 1 ) 500 A 3,329 D Ordinary Shares 05/08/2023 M( 1 ) 93 A 3,422 D Ordinary Shares 05/08/2023 M( 1 ) 800 A 4,222 D Ordinary Shares 05/08/2023 M( 1 ) 31 A 4,253 D Ordinary Shares 05/08/2023 M( 1 ) 750 A 5,003 D Ordinary Shares 05/08/2023 M( 1 ) 24 A 5,027 D Ordinary Shares 05/08/2023 F( 4 ) 1,613 D $ 14.81 3,414 D Ordinary Shares 08/09/2023 S( 5 ) 525 D $ 12.24 2,889 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) ( 2 ) 05/08/2023 M 750 ( 6 ) 03/14/2025 Ordinary Shares 750 ( 2 ) 0 D Dividend Equivalent Rights ( 7 ) ( 3 ) 05/08/2023 M 181 ( 8 ) 03/14/2025 Ordinary Shares 181 ( 3 ) 0 D Stock Options (Right to Buy) ( 2 ) 05/08/2023 M 500 ( 9 ) 12/13/2025 Ordinary Shares 500 ( 2 ) 500 ( 10 ) D Dividend Equivalent Rights ( 7 ) ( 3 ) 05/08/2023 M 93 ( 11 ) 12/13/2025 Ordinary Shares 93 ( 3 ) 51 ( 12 ) D Stock Options (Right to Buy) ( 2 ) 05/08/2023 M 800 ( 13 ) 03/15/2027 Ordinary Shares 800 ( 2 ) 800 D Dividend Equivalent Rights ( 7 ) ( 3 ) 05/08/2023 M 31 ( 14 ) 03/15/2027 Ordinary Shares 31 ( 3 ) 87 D Stock Options (Right to Buy) ( 2 ) 05/08/2023 M 750 ( 15 ) 03/14/2028 Ordinary Shares 750 ( 2 ) 2,250 D Dividend Equivalent Rights ( 7 ) ( 3 ) 05/08/2023 M 24 ( 16 ) 03/14/2028 Ordinary Shares 24 ( 3 ) 190 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other LAWDAY MARK JAMES LUXFER HOLDINGS PLC, LUMNS LANE MANCHESTER, X0M27 8LN See Remarks Signatures /s/ Megan E. Glise under Power of Attorney for Mark J. Lawday 02/14/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Represents the exercise of Stock Options and related Dividend Equivalent Rights on May 8, 2023, as detailed in Table II of this Form 5. This transaction was not previously reported on Form 4 due to an inadvertent administrative error. ( 2 )Stock Options convert 1 for 1, subject to a nominal payment of $1.00 per Ordinary Share. ( 3 )Dividend Equivalent Rights convert 1 for 1, subject to a nominal payment of $1.00 per Ordinary Share. ( 4 )Represents the payment of exercise price and tax liabilities by withholding Ordinary Shares incident to the exercise of derivative securities on May 8, 2023. This transaction was not previously reported on Form 4 due to an inadvertent administrative error. ( 5 )Represents the on-market sale of 525 Ordinary Shares on August 9, 2023. This transaction was not previously reported on Form 4 due to an inadvertent administrative error. ( 6 )The subject Stock Options fully vested and became exercisable on March 14, 2023. ( 7 )Represents Dividend Equivalent Rights accrued on 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, subject to a nominal payment of $1.00 per Ordinary Share. ( 8 )The subject Dividend Equivalent Rights fully vested and became exercisable on March 14, 2023. ( 9 )The subject Stock Options vested and became exercisable on December 13, 2022. ( 10 )The subject Stock Options fully vested and became exercisable on December 13, 2023. As of December 31, 2023, the Stock Options have not been exercised. ( 11 )The subject Dividend Equivalent Rights vested and became exercisable on December 13, 2020, December 13, 2021, and December 13, 2022. ( 12 )The subject Dividend Equivalent Rights fully vested and became exercisable on December 13, 2023. As of December 31, 2023, the Dividend Equivalent Rights have not been exercised. ( 13 )The subject Stock Options vested and became exercisable in equal installments on March 15, 2022 and March 15, 2023. The remaining Stock Options will vest and become exercisable in two equal annual installments on March 15, 2024 and March 15, 2025. ( 14 )The subject Dividend Equivalent Rights vested and became exercisable on March 15, 2022 and March 15, 2023. The remaining Dividend Equivalent Rights will vest and become exercisable in two annual installments on March 15, 2024 and March 15, 2025. ( 15 )The subject Stock Options vested and became exercisable on March 14, 2023. The remaining Stock Options vest and become exercisable in three equal annual installments beginning on March 14, 2024. ( 16 )The subject Dividend Equivalent Rights vested and became exercisable on March 14, 2023. The remaining Dividend Equivalent Rights will vest and become exercisable in three annual installments beginning on March 14, 2024.

Remarks: Vice President and General Manager, Luxfer Gas Cylinders - Europe

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