Elementis : Form of Proxy 2024

Please detach and retain this section.

Admission card

The Annual General Meeting ("AGM") of Elementis plc to be held at the offices of Allen & Overy LLP, One Bishops Square, London, E1 6AD, and electronically on 30 April 2024 at 10.00 am.

Please detach the form below before posting.

Kindly note: this form is issued only to the addressee(s) and is specific to the unique designated account printed hereon. This personalised form is not transferable between different account holders or uniquely designated accounts. Elementis plc and Equiniti Limited accept no liability for any instruction that does not comply with these conditions.

If you would like to attend the meeting electronically, please follow the instructions on pages 11 and 12 of the Notice of Meeting.

You will require the following details: Meeting ID: 131-826-943 SRN: (Shareholder Reference Number)

PIN: This is the first 2 and last 2 digits of the SRN above.

DETACH HEREVoting ID

Task ID

Please detach and post this section. Alternatively, you can vote electronically atwww.sharevote.co.uk using the above numbers.

Form of proxy

I/we being (a) member(s) of Elementis plc (the 'Company') hereby appoint the Chair of the Meeting, or (insert full name clearly in box (1) below)

(1)+

as my/our proxy to vote for me/us on my/our behalf at the Annual General Meeting of the Company to be held at the offices of Allen & Overy LLP, One Bishops Square, London, E1 6AD on 30 April 2024 at 10.00 am and at any adjournment thereof. (Insert in box (2) below the number of shares your proxy is authorised to vote.)

(2)+Tick here if this proxy is one of multiple appointments being made.

If you do not give any directions as to how your proxy should vote on the Resolutions, or on any other business of the Meeting, he/she will exercise his/her discretion as to whether, and if so how, he/she votes. The 'Vote

(3)+withheld' option is to allow you to abstain on any particular Resolution and is not a vote in law and will not be counted as 'For' or 'Against' a Resolution. In the case of a corporation, this proxy must be given under its common seal or be signed on its behalf by an attorney or officer, duly authorised, stating their capacity (e.g. director, secretary).

Signature

Date

+Each number refers to the corresponding note in the explanatory overleaf.

* Special Resolution

Shareholder Reference Number

Please indicate your vote by marking a 'X' in the appropriate boxes.

Resolutions

• 1. To receive the Company's accounts and the reports of the directors and auditors.

• 2. To approve a final dividend.

• 3. To approve the Directors' Remuneration Report.

• 4. To elect Maria Ciliberti as a director.

• 5. To elect Heejae Chae as a director.

• 6. To re-elect John O'Higgins as a director.

• 7. To re-elect Paul Waterman as a director.

• 8. To re-elect Ralph Hewins as a director.

• 9. To re-elect Dorothee Deuring as a director.

• 10. To re-elect Trudy Schoolenberg as a director.

• 11. To re-elect Christine Soden as a director.

• 12. To re-elect Clement Woon as a director.

• 13. To re-appoint Deloitte LLP as auditors.

• 14. To authorise the Audit Committee to determine the remuneration of the auditors.

• 15. To grant authority to the directors to allot shares.

• 16. To authorise political donations.

• 17. *To approve the holding of general meetings at 14 clear days' notice.

• 18. *To disapply statutory pre-emption rights on the allotment of shares.

• 19. *To disapply statutory pre-emption rights on the allotment of shares for an acquisition or capital investment.

• 20. *To renew the Company's authority to purchase its own shares in the market.

ForAgainstVote withheld

Explanatory notes to Form of proxy

(To be read in conjunction with the Notice of Meeting and the accompanying notes.)

• 1. If you want to appoint another person to be your proxy, strike out the words 'Chair of the Meeting' and insert in the box the name of the proxy and initial the alterations. A proxy need not be a member of the Company.

• 2. To enable your proxy to vote all your shares, insert your total shareholding or leave the box blank. Alternatively, if you wish to restrict the number of shares your proxy can vote, insert the number of shares in relation to which your proxy is authorised to act.

• 3. To appoint more than one proxy, (an) additional proxy form(s) may be obtained by calling the Registrars on [phone]*, or you may photocopy this form. Please tick the box provided if the proxy instruction is one of multiple instructions being given. All forms must be signed and returned in the same envelope. Please ensure that the total number of shares for all your proxies does not exceed your total shareholding.

• 4. For this Form of proxy to be valid, detach from the Admission card and deliver to Equiniti Limited, Aspect House, Spencer Road, Lancing, West Sussex BN99 6DA by 10.00 am on 26 April 2024, or 48 hours (excluding non-working days) before the appointed time of any adjourned Meeting. For information about a member's right to appoint a proxy and other rights, please see the notes accompanying the Notice of Meeting.

• 5. Members who wish to appoint a proxy through the CREST system should also refer to the notes in the Notice of Meeting.

• 6. If you are an institutional investor, you may be able to appoint a proxy electronically via the Proxymity platform, a process which has been agreed by the Company and approved by the Registrar. For further information regarding Proxymity, please go to proxymity.io. Your proxy must be lodged by 10.00 am on 26 April 2024 in order to be considered valid. Before you can appoint a proxy via this process, you will need to have agreed to Proxymity's associated terms and conditions. It is important that you read these carefully as you will be bound by them and they will govern the electronic appointment.

• 7. Completing a Form of proxy will not prevent a member from attending in person and voting in person if he/she so wishes.

*Lines are open 8.30am to 5.30pm, Monday to Friday, excluding bank holidays in England and Wales. Please use the country code if calling from outside of the UK.

Allen & Overy's building can be approached from Folgate Street to the north and Brushfield Street to the South.

All visitors to the offices of Allen & Overy LLP are required to provide a form of ID for security purposes. Please report to the firm's reception. The AGM will take place on the first floor, which is accessible via the lifts from the entrance lobby.

The pedestrian footpath (Sun Street Passage) is only accessible from inside Liverpool Street Station on the upper concourse. For a station plan, visithttp://nationalrail.co.uk/stations-and-destinations/stations-made-easy/ london-liverpool-street-station-plan.

Venue address Allen & Overy LLP 1st Floor

One Bishops Square London

E1 6AD

London Underground

The venue is 5 minutes' walk from Liverpool Street tube and train station, and 20 minutes' walk from Moorgate tube station.