Solvay SA

Proxy Solicitation & Information Statement • Apr 26, 2024

To be valid, this form must be received by Solvay SA no later than 22 May 2024 11.59 p.m.

PROXY FOR THE ORDINARY SHAREHOLDERS' MEETING OF SOLVAY SA ON 28 MAY 2024

I, the undersigned (name, first name and address to be completed)

holder of	Solvay shares, on the record date, set on Tuesday 14 May 2024 at midnight, hereby declares I grant
authority to
Name, first name :
Address :
	or failing that, to Michel Washer (former executive of Solvay SA)
each with the right of substitution,

to represent me at the Ordinary Shareholders' Meeting of Solvay SA that will take place on Tuesday 28 May 2024 at 10.30 a.m. (Belgian time) and to vote in my name on all the items on the agenda.

The proxy holder may also sign all deeds, documents, minutes, attendance lists and other documents relating to the Shareholders' Meeting and, in general, do whatever is necessary to fulfill this mandate.

Legal entity shareholders must specify the name(s), first name(s) and capacity of the physical person(s) who sign(s) this proxy form on their behalf. The physical person(s) hereby declare(s) and warrant(s) to Solvay SA to have full authority to execute this proxy form.

Solvay SA must be provided with this proxy, duly completed and signed, by 22 May 2024 11.59 p.m. at the latest. In addition, shareholders must comply with the registration procedure described in the convening notice to the Shareholders' Meeting. The proxy may be sent either by mail to the company's registered office: Solvay SA, Shareholders' Meeting, 310 rue de Ransbeek, 1120 Brussels, or by e-mail to ag.solvay@solvay.com.

* * *

Each proxy must provide precise voting instructions for each item on the agenda.

In the absence of indication on how to vote for one or more of the resolutions proposed below or if the instructions as to the meaning of the vote given by the shareholder are not clear, this will constitute an instruction to vote in favour of the relevant proposed resolution(s).

* * *

Ordinary Shareholders' Meeting

• 1. Management report for the financial year 2023 (including the Corporate Governance Statement)
• 1. Auditor's report for the financial year 2023

3. Communication of the consolidated accounts for the financial year 2023 – Auditor's report on the consolidated accounts

4. Approval of the annual accounts for the financial year 2023 – Allocation of profits and determination of the dividend

It is proposed to approve the annual accounts and the allocation of profits for the financial year 2023 and to set the gross dividend per share at EUR 2.43. After deduction of the gross interim dividend of EUR 1.62 per share paid on 17 January 2024, the balance of the gross dividend amounts to EUR 0.81 per share, payable as from 5 June 2024.

FOR AGAINST ABSTAIN

5. Discharge of the directors for the financial year 2023

It is proposed to grant discharge to the directors in office during the financial year 2023 for the performance of their duties during the financial year 2023.

FOR AGAINST ABSTAIN

6. Discharge of the auditor for the financial year 2023

It is proposed to grant discharge to the auditor in office during the financial year 2023 for the performance of its duties during the financial year 2023.

FOR AGAINST ABSTAIN

7. Approval of the remuneration report relating to the financial year 2023

It is proposed to approve the remuneration report relating to the financial year 2023, as included in chapter 6 of the Corporate Governance Statement.

FOR AGAINST ABSTAIN

8. Approval of the revised gross amounts of the directors' pay

Upon recommendation of the Compensation Committee, it is proposed to amend, with effect from 1 January 2024, the gross remuneration of non-executive directors, as follows:

Board of Directors
Chair (*) Retainer	275,000€
Vice-Chair Retainer	95,000€
Member Retainer	67,000€
Attendance Fee	2,000€
Audit and Risk Committee (**)
Chair Retainer	18,000€
Member Retainer	8,000€
Attendance Fee	2,000€
Other Committees (**)
Chair Retainer	16,000€
Member Retainer	6,000€
Attendance Fee	1,000€

(*) The Chairman of the Board is only eligible to earn a retainer and attendance fees with respect to Board Meetings. No additional retainers and/or attendance fees are payable to the Chairman of the Board in connection with Committee meetings.

(**) In addition to the remuneration as a member of the Board of Directors.

FOR AGAINST ABSTAIN

9. Board of Directors: Renewal of mandate

It is proposed to renew the mandate of Ms Aude Thibaut de Maisières for a period of four years, as her current mandate expires at the end of this meeting. Her mandate will expire at the end of the annual shareholders' meeting which will approve the annual accounts relating to the financial year 2027.

FOR AGAINST ABSTAIN

10. Appointment of EY regarding the assurance of sustainability information imposed by the EU Directive 2022/2464 of 14 December 2022 of the European Parliament and the European Council on sustainability reporting (Corporate Sustainability Reporting Directive)

On the proposal of the Board of Directors, acting on the recommendation of the Audit and Risk Committee and on the recommendation of the works council, it is proposed to charge EY Bedrijfsrevisoren BV, with registered office at Kouterveldstraat 7b, 1831 Diegem, Belgium, represented by Eric Van Hoof, with the assignment regarding the assurance of sustainability information for a period that will be aligned with the current mandate as statutory auditor of the statutory financial statements. The assignment regarding assurance of sustainability information is imposed by the EU Directive 2022/2464 of 14 December 2022 of the European Parliament and the European Council on sustainability reporting by companies (the "Corporate Sustainability Reporting Directive" or "CSRD"), which shall be transposed into Belgian law before 6 July 2024. This sustainability information also contains the information required by Article 8 of the European Regulation (EU) 2020/852 on the establishment of a framework to promote sustainable investments (the "EU Taxonomy"). The financial terms of this assignment will be agreed between Solvay and the auditor in accordance with the law transposing the CSRD.

FOR AGAINST ABSTAIN

11. Approval of the change of control provision relating to the issuance of euro senior unsecured fixed rate bonds for an aggregate nominal amount of EUR 1.5 billion by Solvay

Pursuant to article 7:151 of the Companies and Associations Code, it is proposed to approve condition 6(f) of the (i) 750,000,000 EUR 3.875 per cent. fixed rate senior unsecured rate bonds due 2028 and (ii) 750,000,000 EUR 4.250 per cent. fixed rate senior unsecured bonds due 2031, issued by Solvay, whereby the bondholders are granted an individual right to request early redemption of their bonds if Solvay is subject to a change of control followed by a rating downgrade or rating withdrawal.

FOR AGAINST ABSTAIN

1. Miscellaneous

* * *

In case shareholders, in accordance with Article 7:130 of the Code of Companies and Associations, exercise their right to add items to the agenda and/or to submit resolution proposals with regard to existing agenda items or new items to be added to the agenda, proxies submitted prior to the publication of the revised agenda shall remain valid for the agenda items that they cover. Solvay SA will also make the revised agenda and a revised model of shareholder proxy form available on its website (http://www.solvay.com/en/investors/shareholders-meeting/index.html) at the latest on 13 May 2024, in order to allow shareholders who would wish to give specific voting instructions on the new agenda items and/or new/alternative proposed resolutions. In case new/alternative proposed resolutions are submitted with respect to agenda items existing after the notified proxies, the proxy holder shall abstain from voting on the new/alternative proposed resolutions. However, in this case, shareholders will have the possibility to send a new proxy to Solvay SA, using the revised proxy form mentioned in the previous paragraph.

PROTECTION OF PERSONAL DATA

Solvay SA is responsible for processing the personal data it receives from shareholders and proxies in the context of the Shareholders' Meeting in accordance with the applicable data protection laws, including the European Regulation 2016/679 of 27 April 2016 on the protection of natural persons with regard to the processing of personal data and on the free movement of such data (GDPR).

This personal data consists mainly of identification data of shareholders, their representatives or proxies, contact data (e.g. postal address, telephone number, e-mail address), number and type of shares, intention to participate, attendance at the Shareholders' Meeting, questions asked, votes cast, etc.

This data will be used to prepare and manage the attendance and voting process for the Shareholders' Meeting, as described in the convening notice, and will be passed on to third parties assisting the company for the above purposes, in particular Lumi. This processing of personal data is necessary in order to meet the legal obligations of Solvay SA. If Solvay SA does not process this personal data, it will not be able to allow the person concerned to be present or to be represented at the Shareholders' Meeting and/or to register the vote as a shareholder of Solvay SA.

This information will not be kept longer than necessary for the same purposes, i.e. 10 years after the Shareholders' Meeting.

For more information, shareholders and proxy holders can consult our "Data Protection and Privacy Policy" via the link https://www.solvay.com/en/information/data-protection-and-privacy-policy.html.

As set out in our Data Protection Policy referred to above, you also have rights with respect to your personal data in accordance with the applicable legal conditions and limits, namely the right of access to your personal data, the rectification or deletion thereof, as well as the right to restrict processing, the right to object to processing, the right to data portability and the right to lodge a complaint with the competent supervisory authority - in Belgium, the Data Protection Authority).

You can exercise your rights mentioned above by contacting the Corporate Secretary of Solvay SA at, Solvay SA, 310, rue de Ransbeek - 1120 Brussels (Belgium) (tel: +32 (0) 2 264 15 32 / e-mail: corporate.secretary@solvay.com).

Signed at , on 2024.

Signature

NOTICE OF ATTENDANCE

I, the undersigned

Owner of the above-mentioned registered shares, advise the said company of my intention to attend the Ordinary Shareholders' Meeting that will be held on Tuesday 28 May 2024 at 10.30 a.m., at Event Lounge, Boulevard General Wahis 16/F, 1030 Brussels, with all shares registered under my name at the record date, on Tuesday 14 May 2024 at midnight.

Signed at , on 2024.

Signature(s)

SOLVAY SA must be in possession of this notice of attendance, duly completed and signed, by Wednesday 22 May 2024 11.59 p.m. at the latest.

This document can be sent to Solvay SA,

• either by post to the following address: Solvay SA, Shareholders' Meeting, rue de Ransbeek 310, 1120 Brussels,

• or by e-mail to the following address: ag.solvay@solvay.com.

VOTE BY CORRESPONDENCE

I the undersigned_________________________________________________________________________________

Legal entity shareholders must specify the name (s), first name(s) and capacity of the physical person(s) who sign(s) this vote by correspondence form on their behalf. If the undersigned is not a physical person who executes this vote by correspondence form himself/herself, the signatory hereby declares and warrants to Solvay SA to have full authority to execute this vote by correspondence form on behalf of the undersigned.

holder of:

________________registered shares,

________________dematerialised shares,

on the record date, of Solvay SA, with registered office at 310 Rue de Ransbeek, 1120 Brussels,

exercise my voting right in the following way on the items on the agenda of the Solvay SA Ordinary Shareholders' Meeting that will take place on Tuesday 28 May 2024 at 10.30 a.m. (Belgian time) at the Event Lounge, Boulevard Général Wahis 16/F, 1030 Brussels.

This vote is also valid for any Shareholders' Meeting that will be convened with the same agenda, provided that the shareholder complies with the registration and confirmation procedures provided for such Meeting.

Ordinary Shareholders' Meeting

1. Management report for the financial year 2023 (including the Corporate Governance Statement)

2. Auditor's report for the financial year 2023

3. Communication of the consolidated accounts for the financial year 2023 – Auditor's report on the consolidated accounts

4. Approval of the annual accounts for the financial year 2023 – Allocation of profits and determination of the dividend

It is proposed to approve the annual accounts and the allocation of profits for the financial year 2023 and to set the gross dividend per share at EUR 2.43. After deduction of the gross interim dividend of EUR 1.62 per share paid on 17 January 2024, the balance of the gross dividend amounts to EUR 0.81 per share, payable as from 5 June 2024.

FOR AGAINST ABSTAIN

5. Discharge of the directors for the financial year 2023

It is proposed to grant discharge to the directors in office during the financial year 2023 for the performance of their duties during the financial year 2023.

FOR AGAINST ABSTAIN

6. Discharge of the auditor for the financial year 2023

It is proposed to grant discharge to the auditor in office during the financial year 2023 for the performance of its duties during the financial year 2023.

FOR AGAINST ABSTAIN

7. Approval of the remuneration report relating to the financial year 2023

It is proposed to approve the remuneration report relating to the financial year 2023, as included in chapter 6 of the Corporate Governance Statement.

FOR AGAINST ABSTAIN

8. Approval of the revised gross amounts of the directors' pay

Upon recommendation of the Compensation Committee, it is proposed to amend, with effect from 1 January 2024, the gross remuneration of non-executive directors, as follows:

Board of Directors
Chair (*) Retainer	275,000€
Vice-Chair Retainer	95,000€
Member Retainer	67,000€
Attendance Fee	2,000€
Audit and Risk Committee (**)
Chair Retainer	18,000€
Member Retainer	8,000€
Attendance Fee	2,000€
Other Committees (**)
Chair Retainer	16,000€
Member Retainer	6,000€
Attendance Fee	1,000€

(*) The Chairman of the Board is only eligible to earn a retainer and attendance fees with respect to Board Meetings. No additional retainers and/or attendance fees are payable to the Chairman of the Board in connection with Committee meetings.

(**) In addition to the remuneration as a member of the Board of Directors.

FOR AGAINST ABSTAIN

9. Board of Directors: Renewal of mandate

It is proposed to renew the mandate of Ms Aude Thibaut de Maisières for a period of four years, as her current mandate expires at the end of this meeting. Her mandate will expire at the end of the annual shareholders' meeting which will approve the annual accounts relating to the financial year 2027.

FOR AGAINST ABSTAIN

10. Appointment of EY regarding the assurance of sustainability information imposed by the EU Directive 2022/2464 of 14 December 2022 of the European Parliament and the European Council on sustainability reporting (Corporate Sustainability Reporting Directive)

On the proposal of the Board of Directors, acting on the recommendation of the Audit and Risk Committee and on the recommendation of the works council, it is proposed to charge EY Bedrijfsrevisoren BV, with registered office at Kouterveldstraat 7b, 1831 Diegem, Belgium, represented by Eric Van Hoof, with the assignment regarding the assurance of sustainability information for a period that will be aligned with the current mandate as statutory auditor of the statutory financial statements. The assignment regarding assurance of sustainability information is imposed by the EU Directive 2022/2464 of 14 December 2022 of the European Parliament and the European Council on sustainability reporting by companies (the "Corporate Sustainability Reporting Directive" or "CSRD"), which shall be transposed into Belgian law before 6 July 2024. This sustainability information also contains the information required by Article 8 of the European Regulation (EU) 2020/852 on the establishment of a framework to promote sustainable investments (the "EU Taxonomy"). The financial terms of this assignment will be agreed between Solvay and the auditor in accordance with the law transposing the CSRD.

FOR AGAINST ABSTAIN

11. Approval of the change of control provision relating to the issuance of euro senior unsecured fixed rate bonds for an aggregate nominal amount of EUR 1.5 billion by Solvay

Pursuant to article 7:151 of the Companies and Associations Code, it is proposed to approve condition 6(f) of the (i) 750,000,000 EUR 3.875 per cent. fixed rate senior unsecured rate bonds due 2028 and (ii) 750,000,000 EUR 4.250 per cent. fixed rate senior unsecured bonds due 2031, issued by Solvay, whereby the bondholders are granted an individual right to request early redemption of their bonds if Solvay is subject to a change of control followed by a rating downgrade or rating withdrawal.

FOR AGAINST ABSTAIN

12. Miscellaneous

Data Protection

Solvay is responsible for the processing of the personal information that it receives from shareholders in the context of the Meeting in accordance with applicable data privacy laws.

Such information will be used for the purposes of analyzing and administrating the attendance and voting process in connection with the Meeting, as set out in this convening notice, and will be transferred to third parties assisting the Company for the above purposes. This information will not be kept longer than necessary for these purposes. Shareholders can consult the "Data Protection and Privacy Policy" with the link https://www.solvay.com/en/information/data-protection-and-privacy-policy.html. They may request access to their data and any additional modification by contacting the Corporate Secretary of Solvay SA at, Solvay SA, [310, rue de Ransbeek - 1120](https://maps.google.com/?q=310,+rue+de+Ransbeek+-+1120+Brussels+(Belgium&entry=gmail&source=g) [Brussels (Belgium)](https://maps.google.com/?q=310,+rue+de+Ransbeek+-+1120+Brussels+(Belgium&entry=gmail&source=g) (tel: +32 (0) 2 264 15 32 / e-mail: corporate.secretary@solvay.com

This form will be considered null and void in its entirety if the shareholder has not indicated above his or her choice concerning one or more items on the agenda of the Shareholders' Meeting.

Shareholders who have cast their vote by validly returning this form to the company may not vote by proxy at the Shareholders' Meeting for the number of votes already cast.

Shareholders who wish to vote by correspondence must comply with the practical formalities. Solvay SA must receive this form, duly completed and signed by 22 May 2024 11.59 p.m. at the latest. All practical formalities are set out in the convening notice of the Ordinary Shareholders' Meeting.

This form can be sent by regular mail to the corporate headquarters: Solvay SA, Assemblée Générale, 310 rue de Ransbeek at 1120 Brussels, or by electronic mail to the e-mail address: ag.solvay@solvay.com. In the case of sending via e-mail, a scanned or photographed copy of the completed and signed form should be sent to the company.

Signed at , on 2024.

Signature

SOLVAY SA/NV RPM 0403091220 ORDINARY SHAREHOLDERS' MEETING 28 May 2024 at 10.30 a.m. Event Lounge, Boulevard Général Wahis 16/F, 1030 Brussels

EXPLANATORY NOTE

This note is prepared in accordance with Article 7:129 §3, 4° of the Companies and Associations Code and contains an explanation of the meaning of each item on the agenda of the Ordinary Shareholders' Meeting.

For further information concerning the Ordinary Shareholders' Meeting and the applicable formalities, please refer to the convening notice published on the website of Solvay.

1. Management report for the financial year 2023 (including the Corporate Governance Statement)

The Board of Directors has prepared a management report for the financial year 2023, including the Corporate Governance Statement, which contains all the information required by law.

The management report is available on the website of Solvay, has been sent to the registered shareholders and is also available on request.

This item is included for communication purposes only and does not require a resolution to be adopted.

2. Auditor's report for the financial year 2023

The auditor's report is unqualified.

The auditor's report is available on the website of Solvay, has been sent to the registered shareholders and is also available on request.

This item is included for information purposes only and does not require a resolution to be adopted.

3. Communication of the consolidated accounts for the financial year 2023 – Auditor's report on the consolidated accounts

The consolidated accounts for the financial year 2023 have been verified and approved by the Board of Directors. The auditor's report is unqualified.

These documents are available on the website of Solvay, have been sent to the registered shareholders and are also available on request.

This item is included for communication purposes only and does not require a resolution to be adopted.

4. Approval of the annual accounts for the financial year 2023 - Allocation of profits and determination of the dividend

It is proposed that the annual accounts for the financial year 2023 be approved, that the profits for the financial year 2023 be appropriated and that the gross dividend per share be set at EUR 2.43, meaning that, after deduction of the gross interim dividend of EUR 1.62 per share paid on 17 January 2024, the balance of the gross dividend will amount to EUR 0.81 per share, payable as from 5 June 2024.

The 2023 annual accounts are available on the website of Solvay, have been sent to the registered shareholders and are also available on request.

The Companies and Associations Code requires that the Shareholders' Meeting decide each year on the approval of the annual accounts, as well as on the allocation of profits and the determination of the dividend.

5. Discharge of the directors for the financial year 2023

It is proposed to grant discharge to the directors in office during the financial year 2023 for the performance of their duties during the financial year 2023.

In accordance with the Companies and Associations Code, the Shareholders' Meeting must decide each year, after approval of the annual accounts, by a special vote on the release from liability of the directors.

6. Discharge of the auditor for the financial year 2023

It is proposed to grant discharge to the auditor in office during the financial year 2023 for the performance of its duties during the financial year 2023.

In accordance with the Companies and Associations Code, the Shareholders' Meeting must decide, after approval of the annual accounts, by a special vote on the release from liability of the auditor.

7. Approval of the remuneration report relating to the financial year 2023

It is proposed to approve the remuneration report relating to the financial year 2023, as included in chapter 6 of the Corporate Governance Statement.

The Companies and Associations Code requires that the Shareholders' Meeting decides each year on the approval of the remuneration report. This report gives information on the remuneration of the members of the Board of Directors and the Executive Committee.

8. Approval of the revised gross amounts of the directors' pay

Upon recommendation of the Compensation Committee, the Board reviewed the Board members' remuneration which had remained unchanged since 2005 for Board members and 2012 for the Chairman of the Board. The comprehensive review was initiated due to the evolving nature of the Board's role over the last two decades, accommodating significantly expanded responsibilities, workload, and preparation time to address increasingly complex topics.

The Compensation Committee's review considered market practices and disclosures as well as pay benchmarking data prepared by an independent compensation consultant on Solvay's European peer group. The Compensation Committee aimed to position the remuneration offered to the median of the European peer group.

The review resulted in the Compensation Committee recommended to adapt the fee structure for Board members to focus on retainer fees while decreasing meeting fees, recognizing that attendance at meetings is an inherent duty, while the retainer better compensates for the extensive preparation, research, and additional engagements required outside of formal meetings.

Board of Directors
Chair (*) Retainer	275,000€
Vice-Chair Retainer	95,000€
Member Retainer	67,000€
Attendance Fee	2,000€
Audit and Risk Committee (**)
Chair Retainer	18,000€
Member Retainer	8,000€
Attendance Fee	2,000€
Other Committees (**)
Chair Retainer	16,000€
Member Retainer	6,000€
Attendance Fee	1,000€

(*) The Chairman of the Board is only eligible to earn a retainer and attendance fees with respect to Board Meetings. No additional retainers and/or attendance fees are payable to the Chairman of the Board in connection with Committee meetings.

(**) In addition to the remuneration as a member of the Board of Directors.

The above proposed changes will take effect as from 1 January 2024.

9. Board of Directors: Renewal of mandate

The mandate of Ms Aude Thibaut de Maisières expires at the end of this meeting. It is proposed to renew her mandate for a period of four years expiring at the end of the annual shareholders' meeting which will approve the annual accounts relating to the financial year 2027.

10. Appointment of EY regarding the assurance of sustainability information imposed by the EU Directive 2022/2464 of 14 December 2022 of the European Parliament and the European Council on sustainability reporting (Corporate Sustainability Reporting Directive)

On the proposal of the Board of Directors, acting on the recommendation of the Audit and Risk Committee and on the recommendation of the works council, it is proposed to charge EY Bedrijfsrevisoren BV, with registered office at Kouterveldstraat 7b, 1831 Diegem, Belgium, represented by Eric Van Hoof, with the assignment regarding the assurance of sustainability information for a period that will be aligned with the current mandate as statutory auditor of the statutory financial statements. The assignment regarding assurance of sustainability information is imposed by the EU Directive 2022/2464 of 14 December 2022 of the European Parliament and the European Council on sustainability reporting by companies (the "Corporate Sustainability Reporting Directive" or "CSRD"), which shall be transposed into Belgian law before 6 July 2024. This sustainability information also contains the information required by Article 8 of the European Regulation (EU) 2020/852 on the establishment of a framework to promote sustainable investments (the "EU Taxonomy"). The financial terms of this assignment will be agreed between Solvay and the auditor in accordance with the law transposing the CSRD.

11. Approval of the change of control provision relating to the issuance of euro senior unsecured fixed rate bonds for an aggregate nominal amount of EUR 1.5 billion by Solvay

Pursuant to Article 7:151 of the Companies and Associations Code, the shareholders' meeting is solely competent to approve clauses conferring rights to third parties that give rise to "substantial" debt commitments of the company and where the exercise of such rights depends on the occurrence of a change of control.

On 3 April 2024, Solvay issued (i) 750,000,000 EUR 3.875 per cent. fixed rate senior unsecured bonds due 2028 and (ii) 750,000,000 EUR 4.250 per cent. fixed rate senior unsecured bonds due 2031 (the "Bonds"). In this framework, a change of control clause was included in condition 6(f) (Redemption at the option of Bondholders following a Change of Control) of the terms and conditions of the Bonds.

The change of control clause provides that (i) upon the occurrence of a change of control of Solvay (as defined in the terms and conditions of the Bonds) and (ii) if Solvay is rated, as a result of such change of control, Solvay is downgraded or its rating is withdrawn, the holders of the Bonds have an individual right to request early redemption of their Bonds at the agreed early redemption amount.

Article 7:151 of the Companies and Associations Code requires that the Shareholders' Meeting decides on the approval of the change of control clause.

12. Miscellaneous

Registration instructions Lumi Connect

Welcome to Lumi Connect!

Lumi Connect is a platform for Shareholder Meeting registration and voting.

By clicking on the link www.lumiconnect.com , you can now register for the AGM of SOLVAY SA on May 28, 2024. There are no costs associated for you as a shareholder to register and vote via the Lumi Connect platform.

The deadline for registration on the Lumi Connect platform is Wednesday May 22, 2024 midnight.

Please read the following information carefully before proceeding.

Step 1 If you don't have a Lumi Connect account, please sign up first (go to www.lumiconnect.com). You will receive an email to activate your account. After confirmation, please login with your email address and password.

Step 2 You can now start with the registration.

• After filling in your phone number and National ID number, you need to select the intermediary through whom you have bought the SOLVAY shares. A dropdown menu automatically fills in the BIC/LEI number. If your intermediary is not on the list, choose OTHER and fill in the data manually.
• If you are a nominative shareholder, you don't need to fill in your intermediary and share dealing account number, you can just select "NOMINATIVE".
• Now fill in your share dealing account number (enter only numbers).
• Indicate the total number of SOLVAY shares you own in your previously indicated share dealing account number.
• If you wish you can add additional information. For instance, you require special assistance (wheelchair) to join the General Meeting.
• You can also register a question you wish to ask the Chairman of the Meeting.

All fields must be correctly filled in.

You will see a confirmation page that you need to check before pressing CONTINUE at the bottom.

Step 3 You are now requested to indicate how you would like to participate:

• Request to attend (in person in the room, with voting during the AGM)
• Request to attend the virtual meeting (with voting remotely during the virtual AGM)

This year it is no longer possible to complete a proxy or vote by correspondence via the platform. You must send these documents directly to Solvay SA - General Meeting, rue de Ransbeek, 1120 Brussels or via the e-mail address: ag.solvay@solvay.com.

IMPORTANT

You must press SUBMIT at the bottom to submit your votes.

Then click on FINISH to finalize your registration.

The voting process is now completed. You can now close your browser.

At any time you can log in again and change your status by pressing cancel and reselect your preferred meeting participation option.

What will happen next?

Pre-meeting timeline:

Day 14

Record date

On May 14, 2024 midnight, the legal registration date ends. In order to vote you should own the shares on this date.

Closing date

As a shareholder you must have registered on Lumi Connect the latest by May 22, 2024 in order to attend the meeting.

Lumi starts verification

Starting on May 21, 2024, Lumi will check with your intermediary if you are the beneficiary of your indicated shares, based on the registration data you have provided.

Upon approval, you will be notified by email that your registration and your direct votes have been approved. In the mail, you will receive a login and password to attend the (virtual) General Meeting.

Day 0	Meeting day
When logging in, you will notice that your meeting participation request form has now become your attendance card, you will see the QR code and barcode.
The QR code will be used to register when you attend the meeting in-room.
To attend the meeting virtually you can just login
again into your account (https://my.lumiagm.com) and click on "Join
Meeting".

If you have not yet casted your votes before the meeting, you will be able to do so during the (virtual) meeting. If you attend the meeting in person in the room, upon verification with your ID card at the registration desk, you will receive an electronic voting box. If you have casted your votes before the meeting, you are also welcome to join the virtual meeting.

Where can I find more information on the SOLVAY Annual General Meeting?

You will find all information about the SOLVAY Annual General Meeting on May 28, 2024 on

http://www.solvay.com/en/investors/shareholders-meeting/index.html