This announcement contains inside information for the purposes of Article 7 of the Market Abuse Regulation (EU) 596/2014 as it forms part of UK domestic law by virtue of the European Union (Withdrawal) Act 2018 ("UK MAR"), and is disclosed in accordance with the Company's obligations under Article 17 of UK MAR.  The persons taking responsibility for this announcement are the Company contacts named below.

NIOX GROUP PLC

("NIOX" or the "Company" and, together with its subsidiaries, the "Group")

Return of Capital by way of Special Dividend

Further to the announcement on 18 May 2023 that the Board believes that the cash generation and resources of the Group are now at a level where it is appropriate to commence the payment of a dividend, the Company is pleased to announce that a special dividend of 2.5p per ordinary share will be paid on 15 September 2023 to shareholders on the register as at Friday 18 August 2023. The associated ex-dividend date will be Thursday 17 August 2023.

Ian Johnson, NIOX's Executive Chairman, said: "I am pleased that the operating income we are now generating has enabled us to fund a special dividend in addition to meeting the ongoing operating needs of the business. We remain confident in the prospects for the business and now anticipate paying further dividends to shareholders from our ongoing cash flow."

Contacts

NIOX

Ian Johnson, Executive Chairman                                                                   Tel: +44 (0) 1865 405 560

Michael Roller, Chief Financial Officer

Singer Capital Markets (Nominated Adviser and Broker)

Aubrey Powell/ Jen Boorer                                                                              Tel: +44 (0) 20 7496 3000

About NIOX

Our mission is to improve asthma diagnosis and management by greater patient access to FeNO testing. Asthma is one of the biggest healthcare issues globally with 340 million sufferers, many of whom are undiagnosed or are misdiagnosed. The Group is engaged in the design, development, and commercialisation of medical devices for the measurement of FeNO, a precise biomarker for asthma. Our market leading device, NIOX VERO®, is increasingly recognised by healthcare professionals as an important tool to improve the diagnosis and management of asthma. NIOX VERO® is also the device of choice by leading clinical research organisations for respiratory studies.

NIOX provides products and services via its direct sales organisation and extensive distributor network in 50 countries. For more information, please visit www.niox.com