How Clean Air Classrooms will solve the UK’s school attendance crisis.


How Clean Air Classrooms will solve the UK’s school attendance crisis.

Twitter Space Event, 15 September 2022: SafeEdForAll hosted ‘Ask the Experts,’ a Q&A session on ‘Removal of Airborne Pollution and Pathogens in Schools.’ Guest speakers, HVAC Engineer Joey Fox and NEU Rep Karam Bales, answered questions from parents and school staff. 

SafeEdForAll is a parent-led grassroots group advocating against physical harm in UK Schools and one of many groups campaigning to raise school attendance to pre-pandemic levels. 

SafeEdForAll Parent Advocate Sarah Saul said:

“Whatever anyone’s experiences or views of schools over the last two years, one uniting aim is surely to improve the attendance of children and school staff. Non-attendance due to avoidable ailments and illnesses is nothing new.”

In 2020, the landmark case of 9-year-old Ella Kissi Debrah—the first person in the world to have air pollution listed as the cause on her death certificate—spotlighted the importance of Clean Air For All. Since early 2020, the UK has accelerated its learning on airborne pollution and pathogens and how they can harm an individual’s health and disrupt learning for entire year groups and schools.

SafeEdForAll Parent Advocate Sarah Saul went on to say:

For a long time, it has been inevitable that if a student or staff member attends a class with a stomach ‘bug’ or an illness like chicken pox, influenza or a cold, it’s not long before many more in class also have to take some time off to recuperate. 

Time away from class can lead to students trying to catch up with class programs or missing out on key lessons. Staff absence means reliance on costly supply staffing and a lack of learning continuity. 

Let’s focus efforts, not just on claiming to want to improve attendance but also finding practical solutions that improve the indoor environment, ensuring it isn’t contributing to increased absenteeism.”

The Department for Education (DfE) guidance for schools is to open windows as a health measure against seasonal illnesses and CO2 concentration in classrooms. However, the DfE Health and Safety guidance is not equitable across the school estate:

Teacher and UNIFY: One Education Union Officer, Karam Bales, said:

Many schools in England are in old buildings which have been added to, and windows with corridors and other classrooms built around them. What I found working with schools’ Health and Safety reps in their CO2 monitoring, a lot of classrooms are well over 1500pmm. Some schools are dilapidated, and the windows have been nailed shut because they haven’t had the money to repair them. On the other hand, you do have some nice new builds. For instance, my school has a new science block where you can open windows to keep the CO2 readings to about 500ppm.

However, research has shown that 98% of state schools and 3.1 million children in London are exposed to air pollution exceeding WHO safe limits. For many students and school staff in the UK, opening windows merely swaps harmful indoor pollution with toxic outdoor pollution. This clearly demonstrates a need for mechanical filtration and ventilation in UK schools.

This year, the Air Quality in Classrooms report found that 72% of UK classrooms have “below standard” air quality, affecting cognitive abilities and physical and mental health. In 2014, a Scottish study in the Journal of School Health by Santosh et al. showed a link between inadequate classroom ventilation and reduced school attendance and educational attainment in children.

Teacher and UNIFY: One Education Union Officer, Karam Bales, said:

“There has been virtually zero investment in ventilation by the government. The DfE sent a survey for schools to fill in but didn’t notify schools that the survey had gone out and was only open for two weeks. During that time, schools had to take CO2 monitor readings, but most schools were still waiting for their CO2 monitors to arrive. By the time the survey ended, the DfE had received a minimal response, claiming that 98% of schools have good ventilation and don’t need to invest in their filters. So we also have an information deficit regarding the real state of our school infrastructure.”

Unfortunately, many campaigners and DfE’s focus has been to ignore parents’ and educators’ concerns around the poor indoor air quality behind many absences. Over the last three years, SafeEdForAll has collected parents’ and teachers’ concerns, and we have listened. Last week, a @SafEdForAll_UK Twitter poll asked parents if their children had been supported to breathe Clean Air in class in the previous 3 years. 89% of respondents answered NO.

SafeEdForAll Parent Advocate Claire Cozler said:

“I’m a former teacher, and we all know that as classrooms got smaller, class sizes got bigger, the actual space got smaller. And any teacher will tell you that we have children falling asleep in class because there’s literally not enough fresh air, especially in built up areas. It’s something that’s been going on for a long time.”

In the current Cost of Living Crisis, many parents and teachers are even more concerned about indoor air quality.

SafeEdForAll Parent Advocate, Dr Marc Redmile, said:

“A few parents have contacted us for advice because their children’s schools are turning their HEPA filters off to save money. The idea that schools would save £1.24 per child per year by turning off the HEPA filters, sacrificing their health, is hard to come to terms with.”

SafeEdForall believes DfE could achieve a significant win in improving attendance by lowering students’ illness and CO2 levels in school buildings.

In the wake of the pandemic, schools were hit hard by low attendance due to illness and clinically vulnerable families with no option but to continue shielding. 

SafeEdForAll Parent Advocate Sarah Saul said:

“Rather than sole reliance on soundbites regarding attendance combined with threats of punitive measures for poor attendance, it would be refreshing if politicians and school leaders took practical steps to look at the issues of poor attendance holistically. Improving indoor air quality is one practical tool. Let’s use it!”

Indeed, instead of tackling parents’ Health and Safety concerns, the DfE has gone as far as to recommend punitive measures to Local Authorities and install a live attendance tracker in 14,000 schools nationwide, raising data privacy concerns.

HVAC Engineer Joey Fox said:

“Clean air is one of the only sustainable required long-term solutions. I don’t want my kids to be still wearing masks in a few years and having to do things like rapid testing. They were all essential parts of the initial [pandemic] response which would always be limited. Getting clean air into school has to be our focus.”


Joey Fox 

OSPE Chartered HVAC Engineer and Indoor Air Quality (IAQ) Chair, Toronto, Canada.

Karam Bales 

Teacher and UNIFY: One Education Union Officer, Karam Bales

Dr Marc Redmile

SafeEdForAll Parent Advocate

Sarah Saul

SafeEdForAll Parent Advocate

Claire Cozler

SafeEdForAll Parent Advocate

Contact and press enquiries 

Claire Cozler 

Nicky Hutchinson


Twitter: @safeedforall_uk


1. Ella Kissi Debra ruling: 

2. London Air Pollution:,with%2024%25%20outside%20of%20London

3. Cost of Living v Children’s Health: 

4. Attendance tracker Data Privacy concerns:

5. Twitter poll on clean air in classrooms

6. CO2 concentration is inversely linked to Child School Attendance and educational attainment:

7. SafeEdForAll Twitter spaces 15 September 2022

8. Air Quality in Classrooms Report


Who is Joey Fox?

JOEY FOX: “I work out for a school board in Canada, and my experience as an HAVAC engineer, is with building automation systems within buildings. It’s not just ventilation that’s been the main focus, but also making sure spaces are comfortable, heated or cooled as necessary.”

What are your main concerns in Canada?

JOEY FOX: “Essentially, we’re worried about different contaminants. But the main focus recently has been obviously COVID and airborne pathogens. The existing standards are not good enough, and not designed to deal with that. We know that proper ventilation does help, but it’s not good enough. And I think in England, there’s a particularly bad issue of this admiration for natural ventilation, which is really synonymous with no ventilation.”

Why is opening a window for ventilation not good enough?

JOEY FOX: “When schools are built to very low standards, natural ventilation is really poor, inconsistent, so mechanical ventilation is much better. In the schools that I deal with, there are none of the same levels of natural ventilation you have in England where it’s just windows. Here, where I am in Canada, it gets really cold for a few months, and you can’t really have windows open. We have exhaust-driven natural ventilation, where no air is supplied to the space. But you have all the classrooms connected to an exhaust fan. So you’re pulling stale air out of the classrooms, which forces fresh air to leak into the classroom either through the building envelope or through windows. 

From a layperson’s perspective, what is the difference between MERV and HEPA?

JOEY FOX: “In HVAC applications, you have MERV 7, MERV 8, designed to only protect the air handling unit from dust which collects on the heating and cooling coils, making them less efficient. In HVAC, we protect the equipment with not great filters. Now that we’ve started caring about actually protecting people, we use much better filters that are more effective at filtering out smaller particles. But the more efficient the filter, the more expensive, and they restrict airflow. MERV 13 is the middle point which gives us the best balance. It’s 60 to 80% effective against smaller particles, and the restriction is not as significant. HEPA is specially designed to filter out 99.95 or so per cent of air particles. So the efficiency of HEPA is way better than anything MERV can do, but it would give you high-pressure drops. So using HEPA isn’t possible in HVAC applications, but when you have a specially designed unit like a portable HEPA filter, you get the best bang for your buck when it comes to how much air you’re pushing through. So you’re cleaning all the air that’s going through where MERV 13 will clean much less.”

Is six air changes per hour still a good metric in a normally crowded classroom? 

JOEY FOX: “The normal class size in Canada is 25 people and usually 200 cubic metres in the classroom. So six air changes per hour, in general, gets you around close to 15 litres per second per person above 10 litres per second per person. The recommended level is 10 litres per second per person, which I think is a good basic level. I would like more to protect against COVID, but just for general health, I think 10 litres per second is a good start, but we’re not there.”

With the cost of living crisis in the UK, how can schools afford to run air filters?

JOEY FOX: “Yeah, I think that’s an important point that people need to realise there might be a cost to this, but one, the detriments, the health problems caused and just air safety. Like having proper healthy air, the benefits are huge. But on top of that, it’s all priorities. If you look at the long-term cost, like you said, £1.00 per kid, per year. This is such a minor cost, and even if it was 50 times more,  it’s nothing compared to other things we spend in schools. I think it’s just another excuse to do nothing as opposed to tackling a real concern.”

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