London Daily

Focus on the big picture.
Wednesday, Jul 30, 2025

Concerns over plan to use ozone to disinfect classrooms in Wales

Concerns over plan to use ozone to disinfect classrooms in Wales

Machines to be used to clean up after Covid outbreaks part of £5.9m initiative to improve air quality

A £3.3m scheme to provide schools in Wales with machines that disinfect classrooms after a Covid outbreak has prompted calls for reassurance over their safety.

The Welsh education ministry said on Monday that all schools, universities and colleges in Wales would be supplied with ozone disinfecting machines for cleaning up Covid-hit classrooms.

Plaid Cymru has raised questions about toxic chemicals contained within the technology. And campaigners questioned why the Welsh government was turning to a harmful substance in schools when safer alternatives are available.

The 1,800 machines, currently in production, will cost £3.3m as part of £5.9m initiative to improve air quality in classrooms and lecture halls.

Developed at Swansea University, the machines convert oxygen in a room to ozone, a chemical that kills Covid in the air and on surfaces, along with other viruses and bacteria. Once a room has been disinfected, the machine, each the size of a suitcase, converts the ozone back to oxygen. But ozone is so toxic that no one will be allowed inside the room when the machine is operating, according to Dr Chedly Tizaoui, who was part of the design team.

Speaking to the Guardian, he said: “When we apply the ozone, the room has to be closed and no one is allowed to be in the room, including pets and animals.

“That is the condition of the application. It is like the use of chlorine, you don’t want to be in an environment where chlorine is dispersed at high concentration. Ozone smells but people are not allowed to smell it. That is extremely important from a safety point of view.”

He said the machines would be programmed to give cleaners time to leave a class room while the machine was in operation. “Once the full cycle is finished then it is safe to go back to the room, and the machine will signal to the cleaner that it is safe to return,” Tizaoui said.


He added that they could be password protected to guard against misuse, and that a strict safety guidelines would be required before they were rolled out.

He said: “They are safe if operated properly. Like a car, if you drive it at 100mph in a 30mph hour limit that is not safe.”

Asked whether the benefits outweighed the risks, Tizaoui said: “It not just a benefit for tackling Covid, ozone is also effective against other seasonal viruses.”

Announcing the initiative, Rebecca Evans, the minister for finance and local government, said: “By investing in new technology such as ozone disinfecting machines, we’re ensuring learners can stay in school and colleges as Wales moves beyond the pandemic.”

But Dr Eilir Hughes, a GP on the Llŷn peninsula and a member of the Fresh Air Wales campaign, was not convinced. He said: “If you have to put in place a lot of health and safety guidelines in rolling it out then it really needs to be worth it.

“Adding a toxic substance to the environment raises concerns about how it will react to chemicals particularly in soft furnishings. Is it sensible to be testing this in schools?”

In an article published online on Monday in Nation Cymru he wrote: “Using ozone to disinfect does seems counterintuitive. In an attempt to lower the risk of harm to human health, we are using toxic chemicals when safer alternatives are available.

“And suggesting that disinfecting potentially infected air when no one is present to breath it is an insult to our intelligence.”

Hughes argued that better ventilation in schools was safer and a more effective means of tackling Covid in the classroom.

He said: “Instead of rolling out expensive, untried, unnecessary technology that has the potential of being damaging to the environment and dangerous to human health, we should place our efforts on interventions that provide the greatest benefit in reducing risk … If natural ventilation is provided for indoor settings, transmission reduces by up to 70%.”

Plaid Cymru’s education spokesperson, Siân Gwenllian, said: “The use of ozone disinfecting machines is controversial to say the least and we all need to be satisfied that Welsh government is absolutely certain that they are a safe option before introducing them.”

A Welsh government spokesman said the machines were only for disinfecting empty indoor spaces. He said: “These machines have been developed to speed-up the decontamination of classrooms following a confirmed outbreak of covid-19 only, and not as a form of air purification for occupied indoor spaces.”

The Welsh government will also be providing CO2 sensors to schools, colleges and universities to improve ventilation, after a similar move in England.

Newsletter

Related Articles

0:00
0:00
Close
Former Judge Charged After Drunk Driving Crash Kills Comedian in Brazil
Jeff Bezos hasn’t paid a dollar in taxes for decades. He makes billions and pays $0 in taxes, LEGALLY
China Increases Use of Exit Bans Amid Rising U.S. Tensions
IMF Upgrades Global Growth Forecast as Weaker Dollar Supports Outlook
Procter & Gamble to Raise U.S. Prices to Offset One‑Billion‑Dollar Tariff Cost
House Republicans Move to Defund OECD Over Global Tax Dispute
Botswana Seeks Controlling Stake in De Beers as Anglo American Prepares Exit
Trump Administration Proposes Repeal of Obama‑Era Endangerment Finding, Dismantling Regulatory Basis for CO₂ Emissions Limits
France Opens Criminal Investigation into X Over Algorithm Manipulation Allegations
A family has been arrested in the UK for displaying the British flag
Mel Gibson refuses to work with Robert De Niro, saying, "Keep that woke clown away from me."
Trump Steamrolls EU in Landmark Trade Win: US–EU Trade Deal Imposes 15% Tariff on European Imports
ChatGPT CEO Sam Altman says people share personal info with ChatGPT but don’t know chats can be used as court evidence in legal cases.
The British propaganda channel BBC News lies again.
Deputy attorney general's second day of meeting with Ghislaine Maxwell has concluded
Controversial March in Switzerland Features Men Dressed in Nazi Uniforms
Politics is a good business: Barack Obama’s Reported Net Worth Growth, 1990–2025
Thai Civilian Death Toll Rises to 12 in Cambodian Cross-Border Attacks
TSUNAMI: Trump Just Crossed the Rubicon—And There’s No Turning Back
Over 120 Criminal Cases Dismissed in Boston Amid Public Defender Shortage
UN's Top Court Declares Environmental Protection a Legal Obligation Under International Law
"Crazy Thing": OpenAI's Sam Altman Warns Of AI Voice Fraud Crisis In Banking
The Podcaster Who Accidentally Revealed He Earns Over $10 Million a Year
Trump Announces $550 Billion Japanese Investment and New Trade Agreements with Indonesia and the Philippines
US Treasury Secretary Calls for Institutional Review of Federal Reserve Amid AI‑Driven Growth Expectations
UK Government Considers Dropping Demand for Apple Encryption Backdoor
Severe Flooding in South Korea Claims Lives Amid Ongoing Rescue Operations
Japanese Man Discovers Family Connection Through DNA Testing After Decades of Separation
Russia Signals Openness to Ukraine Peace Talks Amid Escalating Drone Warfare
Switzerland Implements Ban on Mammography Screening
Japanese Prime Minister Vows to Stay After Coalition Loses Upper House Majority
Pogacar Extends Dominance with Stage Fifteen Triumph at Tour de France
CEO Resigns Amid Controversy Over Relationship with HR Executive
Man Dies After Being Pulled Into MRI Machine Due to Metal Chain in New York Clinic
NVIDIA Achieves $4 Trillion Valuation Amid AI Demand
US Revokes Visas of Brazilian Corrupted Judges Amid Fake Bolsonaro Investigation
U.S. Congress Approves Rescissions Act Cutting Federal Funding for NPR and PBS
North Korea Restricts Foreign Tourist Access to New Seaside Resort
Brazil's Supreme Court Imposes Radical Restrictions on Former President Bolsonaro
Centrist Criticism of von der Leyen Resurfaces as she Survives EU Confidence Vote
Judge Criticizes DOJ Over Secrecy in Dropping Charges Against Gang Leader
Apple Closes $16.5 Billion Tax Dispute With Ireland
Von der Leyen Faces Setback Over €2 Trillion EU Budget Proposal
UK and Germany Collaborate on Global Military Equipment Sales
Trump Plans Over 10% Tariffs on African and Caribbean Nations
Flying Taxi CEO Reclaims Billionaire Status After Stock Surge
Epstein Files Deepen Republican Party Divide
Zuckerberg Faces $8 Billion Privacy Lawsuit From Meta Shareholders
FIFA Pressured to Rethink World Cup Calendar Due to Climate Change
SpaceX Nears $400 Billion Valuation With New Share Sale
×