NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION IN WHOLE OR IN PART, DIRECTLY OR INDIRECTLY, IN OR INTO AUSTRALIA, CANADA, HONG KONG, SINGAPORE, THE UNITED ARAB EMIRATES AND THE UNITED STATES AND ANY OTHER JURISDICTION TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OR REGULATIONS OF SUCH JURISDICTION.

THIS ANNOUNCEMENT IS AN ADVERTISEMENT AND DOES NOT CONSTITUTE A PROSPECTUS OR PROSPECTUS EQUIVALENT DOCUMENT. NOTHING HEREIN SHALL CONSTITUTE AN OFFERING OF ANY SECURITIES. NOTHING IN THIS ANNOUNCEMENT SHOULD BE INTERPRETED AS A TERM OR CONDITION OF THE RIGHTS ISSUE. ANY DECISION TO PURCHASE, SUBSCRIBE FOR, OTHERWISE ACQUIRE, SELL OR OTHERWISE DISPOSE OF ANY NIL PAID RIGHTS, FULLY PAID RIGHTS OR NEW ORDINARY SHARES MUST BE MADE ONLY ON THE BASIS OF THE INFORMATION CONTAINED IN THE PROSPECTUS. PLEASE SEE THE IMPORTANT NOTICE AT THE END OF THIS ANNOUNCEMENT.

SYNTHOMER PLC

COMPLETION OF RIGHTS ISSUE AND
RESULT OF RUMP PLACING

13 October 2023

Following the announcement on 12 October 2023 regarding valid acceptances under the fully underwritten 6 for 1 Rights Issue announced by Synthomer plc (the "Company") on 7 September 2023, the Company confirms Goldman Sachs International, J.P. Morgan Securities plc, Morgan Stanley & Co International plc and Citigroup Global Markets Limited, as underwriters in respect of the Rights Issue, have successfully procured subscribers for all of the 10,319,421 New Ordinary Shares for which valid acceptances were not received, representing approximately 7.4 per cent. of the total number of New Ordinary Shares to be issued pursuant to the fully underwritten Rights Issue, and for all of the 899 Ordinary Shares resulting from the aggregation of fractional entitlements to Consolidated Ordinary Shares, at a price of 200 pence per New Ordinary Share (the "Placing Price").

The net proceeds from the placing of such New Ordinary Shares (after the deduction of the Rights Issue Price of 197 pence per New Ordinary Share and the expenses of procuring subscribers, including any applicable brokerage commissions and VAT which are not recoverable) will be paid (without interest) to those Shareholders whose rights have lapsed in accordance with the terms of the Rights Issue, pro rata to their lapsed provisional allotments, save that individual amounts of less than £5.00 will not be paid to such persons but will be aggregated and will accrue for the benefit of the Company.

Unless the context requires otherwise, capitalised terms used but not otherwise defined in this announcement have the meanings set out in the combined prospectus and circular dated 7 September 2023 (the "Prospectus").

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IMPORTANT NOTICES

This announcement has been issued by and is the sole responsibility of the Company. The information contained in this announcement is for background purposes only and does not purport to be full or complete. No reliance may or should be placed by any person for any purpose whatsoever on the information contained in this announcement or on its accuracy, fairness or completeness. The information in this announcement is subject to change without notice.

This announcement is not a prospectus (or a prospectus equivalent document) but an advertisement for the purposes of the Prospectus Regulation Rules of the Financial Conduct Authority ("FCA"). Neither this announcement nor anything contained in it shall form the basis of, or be relied upon in conjunction with, any offer or commitment whatsoever in any jurisdiction. Investors should not acquire any Nil Paid Rights, Fully Paid Rights or New Ordinary Shares referred to in this announcement except on the basis of the information contained in the Prospectus published by the Company in connection with the Rights Issue.

A copy of the Prospectus is available from the registered office of the Company and on its website at www.synthomer.com/investor-relations/. Neither the content of the Company's website nor any website accessible by hyperlinks on the Company's website is incorporated in, or forms part of, this announcement. The Prospectus provides further details of the New Ordinary Shares, the Nil Paid Rights and the Fully Paid Rights being offered pursuant to the Rights Issue.

This announcement (and the information contained herein) is not for release, publication or distribution, directly or indirectly, in whole or in part, in, into or within the United States of America, its territories and possessions, any State of the United States or the District of Columbia (collectively, the "United States"). This announcement is not an offer for sale or the solicitation of an offer to purchase securities in the United States. Securities may not be offered or sold in the United States absent registration under the US Securities Act of 1933, as amended (the "US Securities Act"), or an exemption therefrom. The Nil Paid Rights, the Fully Paid Rights and the New Ordinary Shares have not been and will not be registered under the US Securities Act or under any securities laws of any state or other jurisdiction of the United States and may not be offered, sold, pledged, taken up, exercised, resold, renounced, transferred or delivered, directly or indirectly, in or into the United States except pursuant to an applicable exemption from, or in a transaction not subject to, the registration requirements of the US Securities Act and in compliance with any applicable securities laws of any state or other jurisdiction of the United States or other jurisdiction. There will be no public offer of the Nil Paid Rights, the Fully Paid Rights or the New Ordinary Shares in the United States. Subject to certain limited exceptions, Provisional Allotment Letters have not been, and will not be, sent to, and Nil Paid Rights have not been, and will not be, credited to the CREST account of, any Qualifying Shareholder with a registered address in or that is known to be located in the United States, or to holders of the Synthomer's American depositary shares. None of the New Ordinary Shares, the Nil Paid Rights, the Fully Paid Rights or the Provisional Allotment Letters, this announcement or any other document connected with the Rights Issue has been or will be approved or disapproved by the United States Securities and Exchange Commission or by the securities commissions of any state or other jurisdiction of the United States or any other regulatory authority, nor have any of the foregoing authorities passed upon or endorsed the merits of the offering of the New Ordinary Shares, the Nil Paid Rights or the Fully Paid Rights, or the accuracy or adequacy of the Provisional Allotment Letters, this announcement or any other document connected with the Rights Issue. Any representation to the contrary is a criminal offence in the United States.

This announcement is for information purposes only and is not intended to and does not constitute or form part of any offer or invitation to purchase or subscribe for, or any solicitation to purchase or subscribe for, Nil Paid Rights, Fully Paid Rights or New Ordinary Shares or to take up any entitlements to Nil Paid Rights in any jurisdiction. No offer or invitation to purchase or subscribe for, or any solicitation to purchase or subscribe for, Nil Paid Rights, Fully Paid Rights or New Ordinary Shares or to take up any entitlements to Nil Paid Rights will be made in any jurisdiction in which such an offer or solicitation is unlawful. The information contained in this announcement and the Prospectus is not for release, publication or distribution to persons in Australia, Canada, Hong Kong, Singapore, the United Arab Emirates and the United States, and any other jurisdiction where the extension or availability of the Rights Issue (and any other transaction contemplated thereby) would breach any applicable law or regulation, and, subject to certain exceptions, should not be distributed, forwarded to or transmitted in or into any jurisdiction, where to do so might constitute a violation of local securities laws or regulations.

The distribution of this announcement, the Prospectus, the Provisional Allotment Letter and the offering or transfer of Nil Paid Rights, Fully Paid Rights or New Ordinary Shares into jurisdictions other than the United Kingdom may be restricted by law, and, therefore, persons into whose possession this announcement, the Prospectus, the Provisional Allotment Letter and/or any accompanying documents comes should inform themselves about and observe any such restrictions. Any failure to comply with any such restrictions may constitute a violation of the securities laws of such jurisdiction. In particular, subject to certain exceptions, this announcement, the Prospectus (once published) and the Provisional Allotment Letters (once printed) should not be distributed, forwarded to or transmitted in or into Australia, Canada, Hong Kong, Singapore, the United Arab Emirates and the United States, or any other jurisdiction where the extension or availability of the Rights Issue (and any other transaction contemplated thereby) would breach any applicable law or regulation.

This announcement does not constitute a recommendation concerning any investor's options with respect to the Rights Issue. The price and value of securities can go down as well as up. Past performance is not a guide to future performance. The contents of this announcement are not to be construed as legal, business, financial or tax advice. Each shareholder or prospective investor should consult his, her or its own legal adviser, business adviser, financial adviser or tax adviser for legal, financial, business or tax advice.

NOTICE TO ALL INVESTORS

Each of Goldman Sachs International ("Goldman Sachs"), J.P. Morgan Securities plc (which conducts its UK investment banking business as J.P. Morgan Cazenove) ("J.P. Morgan Cazenove"), Morgan Stanley & Co. International plc ("Morgan Stanley") and Citigroup Global Markets Limited ("Citi") is authorised by the Prudential Regulation Authority and regulated by the FCA and the Prudential Regulation Authority in the United Kingdom. Each of Goldman Sachs, J.P. Morgan Cazenove, Morgan Stanley and Citi is acting exclusively for Synthomer plc and no one else in connection with this announcement and the Rights Issue will not be responsible to anyone other than Synthomer plc for providing the protections afforded to its clients nor for providing advice to any person in relation to the Rights Issue or any matters referred to in this announcement.

None of Goldman Sachs, J.P. Morgan Cazenove, Morgan Stanley or Citi, nor any of their respective subsidiaries, branches or affiliates, nor any of their respective directors, officers or employees owes or accepts any duty, liability or responsibility whatsoever (whether direct or indirect, whether in contract, in tort, under statute or otherwise) to any person who is not a client of Goldman Sachs, J.P. Morgan Cazenove, Morgan Stanley or Citi in connection with the Rights Issue, this announcement, any statement contained herein, or otherwise.

INFORMATION TO DISTRIBUTORS

Solely for the purposes of the product governance requirements of Chapter 3 of the FCA Handbook Product Intervention and Product Governance Sourcebook (the "UK Product Governance Requirements"), and disclaiming all and any liability, whether arising in tort, contract or otherwise, which any "manufacturer" (for the purposes of the UK Product Governance Requirements) may otherwise have with respect thereto, the Nil Paid Rights, Fully Paid Rights and the New Ordinary Shares have been subject to a product approval process, which has determined that they each are: (a) compatible with an end target market of retail investors and investors who meet the criteria of professional clients and eligible counterparties, each as defined in Chapter 3 of the FCA Handbook Conduct of Business Sourcebook; and (b) eligible for distribution through all permitted distribution channels (the "Target Market Assessment"). Notwithstanding the Target Market Assessment, "distributors" (for the purposes of the UK Product Governance Requirements) should note that: the price of the Nil Paid Rights, Fully Paid Rights and the New Ordinary Shares may decline and investors could lose all or part of their investment; the Nil Paid Rights, Fully Paid Rights and the New Ordinary Shares offer no guaranteed income and no capital protection; and an investment in the Nil Paid Rights, Fully Paid Rights and the New Ordinary Shares is compatible only with investors who do not need a guaranteed income or capital protection, who (either alone or in conjunction with an appropriate financial or other adviser) are capable of evaluating the merits and risks of such an investment and who have sufficient resources to be able to bear any losses that may result therefrom. The Target Market Assessment is without prejudice to any contractual, legal or regulatory selling restrictions in relation to the Rights Issue. Furthermore, it is noted that, notwithstanding the Target Market Assessment, the Underwriters will only procure investors who meet the criteria of professional clients and eligible counterparties.

For the avoidance of doubt, the Target Market Assessment does not constitute: (i) an assessment of suitability or appropriateness for the purposes of Chapters 9A or 10A, respectively, of the FCA Handbook Conduct of Business Sourcebook; or (ii) a recommendation to any investor or group of investors to invest in, or purchase, or take any other action whatsoever with respect to, the Nil Paid Rights, Fully Paid Rights and the New Ordinary Shares. Each distributor is responsible for undertaking its own target market assessment in respect of the Nil Paid Rights, Fully Paid Rights and the New Ordinary Shares and determining appropriate distribution channels.

FORWARD-LOOKING STATEMENTS

This announcement contains forward-looking statements, including with respect to financial information, that are based on current expectations or beliefs, as well as assumptions about future events. These forward-looking statements can be identified by the fact that they do not relate only to historical or current facts. In some cases, forward-looking statements use words such as "anticipate", "target", "expect", "estimate", "intend", "plan", "goal", "believe", "will", "may", "should", "would", "could", "is confident", or other words of similar meaning.

None of the Company, its officers, advisers or any other person gives any representation, assurance or guarantee that the occurrence of the events expressed or implied in any forward-looking statements in this announcement will actually occur, in part or in whole.

No undue reliance should be placed on any such statements because they speak only as at the date of this announcement and, by their very nature, they are subject to known and unknown risks and uncertainties and can be affected by other factors that could cause actual results, and the Company's plans and objectives, to differ materially from those expressed or implied in the forward-looking statements. No representation or warranty is made that any forward-looking statement will come to pass. You are advised to read the Prospectus when published and the information incorporated by reference therein in their entirety, and, in particular, the section of the Prospectus headed "Risk Factors", for a further discussion of the factors that could affect the Group's future performance and the industry in which it operates. In light of these risks, uncertainties and assumptions, the events described in the forward-looking statements, including statements regarding prospective financial information, in this announcement may not occur. In addition, even if the Group's actual results of operations, financial condition and the development of the business sectors in which it operates are consistent with the forward-looking statements contained in the Prospectus, those results or developments may not be indicative of results or developments in subsequent periods. These statements are not fact and should not be relied upon as being necessarily indicative of future results, and readers of this announcement are cautioned not to place undue reliance on the forward-looking statements, including those regarding prospective financial information.

No statement in this announcement is intended as a profit forecast or estimate for any period, and no statement in this announcement should be interpreted to mean that underlying operating profit for the current or future financial years would necessarily be above a minimum level, or match or exceed the historical published operating profit or set a minimum level of operating profit, nor that earnings or earnings per share or dividend per share for the Company for the current or future financial years would necessarily match or exceed the historical published earnings or earnings per share or dividend per share for the Company.

Neither the Company nor any of the Underwriters are under any obligation to update or revise publicly any forward-looking statement contained within this announcement, whether as a result of new information, future events or otherwise, other than in accordance with their legal or regulatory obligations (including, for the avoidance of doubt, the Prospectus Regulation Rules, the Listing Rules, MAR, FSMA and Disclosure Guidance and Transparency Rules). Additionally, statements of the intentions or beliefs of the board of directors of the Company reflect the present intentions and beliefs of the board of directors of the Company as at the date of this announcement and may be subject to change as the composition of the board of directors of the Company alters, or as circumstances require.