Response to Rule 2.8 Announcement

Certain information contained within this Announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulation (EU) No. 596/2014 ("MAR") as applied in the United Kingdom. Upon publication of this Announcement, this information is now considered to be in the public domain.

FOR IMMEDIATE RELEASE

11 April 2025

NIOX GROUP PLC

Response to Rule 2.8 announcement by Keensight

& Strategic Update

The Board of NIOX Group plc ("NIOX" or the "Company"; AIM: NIOX) notes the announcement made today by Keensight Capital ("Keensight") under Rule 2.8 of the City Code on Takeovers and Mergers (the "Code"), confirming that, given the prevailing macroeconomic conditions, it does not intend to make a firm offer for the Company. As a result, Keensight are bound by the restrictions set out in Rule 2.8 of the Code. Furthermore, in light of the current macroeconomic backdrop, the NIOX Board has also concluded that continuing the Private Sale Process ("PSP") at this time is unlikely to yield an optimal outcome for shareholders. Accordingly, the PSP is being discontinued with immediate effect.

As noted in the preliminary results announcement on 1 April 2025, the current year has started well. Sales growth in the first quarter for the Group as a whole was 18%. Net cash as at 31 March 2025 was £15.4m. A further trading update will be made at the Company's Annual General Meeting on 14 May 2025.

Legal Entity Identifier: 2138006YAT138TOGA556

The person responsible for arranging the release of this announcement on behalf of NIOX is Sarah Duncan, Group Financial Controller and Company Secretary at NIOX.

For further information, please contact:

Important notices

In accordance with Rule 26.1 of the Takeover Code, a copy of the announcement will be available on NIOX's website at www.niox.com by no later than 12 noon (London time) on the business day following the date of this announcement. The content of the website referred to in this announcement is not incorporated into, and does not form part of, this announcement.

This announcement has been prepared in accordance with English law and information disclosed may not be the same as that which would have been prepared in accordance with the laws of jurisdictions outside England.

Forward-looking statements

This press release contains certain projections and other forward-looking statements with respect to the financial condition, results of operations, businesses and prospects of NIOX. The use of terms such as "may", "will", "should", "expect", "anticipate", "project", "estimate", "intend", "continue", "target" or "believe" and similar expressions (or the negatives thereof) are generally intended to identify forward-looking statements. These statements are based on current expectations and involve risk and uncertainty because they relate to events and depend upon circumstances that may or may not occur in the future. There are a number of factors that could cause actual results or developments to differ materially from those expressed or implied by these forward-looking statements. Any of the assumptions underlying these forward-looking statements could prove inaccurate or incorrect and therefore any results contemplated in the forward-looking statements may not actually be achieved. Nothing contained in this press release should be construed as a profit forecast or profit estimate. Investors or other recipients are cautioned not to place undue reliance on any forward-looking statements contained herein. NIOX undertakes no obligation to update or revise (publicly or otherwise) any forward-looking statement, whether as a result of new information, future events or other circumstances.

Notice related to financial advisers

Lazard & Co., Limited ("Lazard"), which is authorised and regulated in the United Kingdom by the Financial Conduct Authority, is acting exclusively as financial adviser to NIOX and no one else in connection with the matters set out in this announcement and will not be responsible to anyone other than NIOX for providing the protections afforded to clients of Lazard nor for providing advice in relation to the matters set out in this announcement. Neither Lazard nor any of its affiliates 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 Lazard in connection with this announcement, any statement contained herein or otherwise. No representation or warranty, express or implied, is made by Lazard as to the contents of this announcement.

Singer Capital Markets Advisory LLP ("Singer Capital Markets"), which is authorised and regulated in the United Kingdom by the Financial Conduct Authority, is acting exclusively as nominated adviser and broker to NIOX and no one else in connection with the matters set out in this announcement and will not be responsible to anyone other than NIOX for providing the protections afforded to clients of Singer Capital Markets nor for providing advice in relation to the matters set out in this announcement. Neither Singer Capital Markets nor any of its affiliates 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 Singer Capital Markets in connection with this announcement, any statement contained herein or otherwise. No representation or warranty, express or implied, is made by Singer Capital Markets as to the contents of this announcement.

Investec Bank plc is retained as joint broker to NIOX.