Original Article By: Mark Stabler - GMC Instrumentation Ltd

“What is an acceptable CO2 level?”

The question may relate to someone’s home, office, gym, or school but the question remains the same.

Well, I can understand the confusion as most people have only come across 'CO2' when it is mentioned in relation to climate change. It’s well documented that it is increasing and is the key contributor to global warming. Currently the global atmospheric carbon dioxide (CO2) concentration is approximately 420ppm and is increasing on average by around 2ppm per annum. This increase is mainly attributed to the actions of industrialisation and the burning of fossil fuels and thus its collectively our problem! CO2 production has been progressively increasing since the industrial revolution which started here in the UK back in the mid 1700’s. At that stage atmospheric carbon dioxide levels were around 280ppm. Back then the air was generally a lot cleaner than it is now, unless of course you lived in the ‘Black Country’ the birthplace of the industrial revolution!

The growth of Industrialisation quickly spread to the rest of the World and China is now leading the way. The by-product of this is that it is now producing almost 30% of the Worlds CO2 Emissions while good old Blighty now contributes less than 1%.

OK I am not going to go any deeper into global atmospheric carbon dioxide levels or global warming only to say there is actually very little an individual can do other than try to force and then support politically driven change which many people do.

But what about the air that we breathe? Can we improve our own environment and our wellbeing? The answer to that question is a definite Yes! Remember that global atmospheric CO2 figure of 420ppm that I mentioned earlier, well what about if I told you that if you are sitting in your office at work then the CO2 concentration that you are breathing could well be around 800…2000ppm depending on the office size, number of occupants and the ventilation. Or if you are sitting on your own in your smaller home office, as many people have over the last 18 months, then it is probably still around 800…1200ppm. Get together with your family or a few friends around the TV in the evening and you are now probably sitting in a CO2 contaminated atmosphere of around 1200…2000ppm. When you retire to the bedroom in the evening the CO2 levels with two occupants could well peak at over 2500ppm! While you are sleeping you are probably breathing the highest CO2 concentration of your day and maybe for 8 hours you can easily be breathing CO2 levels 5 times greater than the 420ppm that you breathe outside, and it is just down to the air that we exhale.

So, what does this mean? Well although we should of course be concerned about global atmospheric CO2 levels we should also be much more concerned about the air that we breathe while indoors. The problem here once again is down to us, as we pollute the very air we breathe. For us humans the most important ‘ingredient’ in the air we breathe is, of course, oxygen and lucky for us most of the air consists of two components 21% Oxygen and 78% Nitrogen. The remaining 1% is a mixture of other gasses which includes Carbon Dioxide at about 0.04%. When we breathe in ‘Fresh Air’ our lungs utilise the oxygen that we need and then when we exhale it is now approximately 16% oxygen and 4%-5% Carbon Dioxide. So, we breathe out approximately 100 times the level of CO2 that we breathe in! And thus, the more people there are in a room the quicker it gets contaminated until you reach what can be considered levels of concern.

So, what are the levels of concern about CO2. Well to be honest there is no set guidance but as a rule 800ppm to 1000ppm is an achievable level across the full range of environments that we occupy so at least we should try to achieve this.

Now, you cannot physically see the components of the air that we breathe or the effect that we collectively have as we breathe out 100 times more CO2 than we breathe in. But by monitoring your environment in the home, office, gym, or school with a simple CO2 monitor you will be able to make the air that you breathe more ‘visible’ and by making a few adjustments to the airflow around, you will see a real change in the CO2 levels that you breathe and benefit from an improvement in your comfort and long-term wellbeing.

You can read studies if you wish to consider this in more detail (you can find some of these on our own ‘GMCiUK News’ feed) but its common knowledge that the effects of prolonged exposure to high concentrations of CO2 over 1000ppm can result in tiredness, feeling drowsy, headaches, difficulty breathing and loss of concentration. All common effects that will be experienced at sustained levels of CO2 exposure over and above 1000ppm. Some studies are now looking into the effect that long term repetitive exposure to CO2 in the indoor environments can have on the human body potentially causing health problems such as inflammation, reduced cognitive performance and kidney and bone problems.

Here we offer a bit more guidance on the potential levels of CO2 contamination that you may find in your own indoor environment once you start monitoring the air that you breathe. The ‘Traffic Light’ indication of the CO2 monitors that we offer give a very visible warning that acceptable levels have been exceeded.

Fresh Outdoor Air
400…420 ppm is what you would expect outside your home.

 

Optimum Air Quality in your Home
600…800 ppm is the sort of level you should try to maintain.

 

What could you expect in your living room & lounge which are your main living quarters?
600…800 ppm is what you might achieve with a bit of ventilation i.e., internal door ajar and window slightly open.

 

What could you expect in your living room & lounge with a few guests?
1000…2500 ppm yes, it is going to go up that’s for sure so keep the doors ajar if possible and keep some air flowing.

 

What could you expect in your bedrooms while asleep?
1200…2500! Well, it might surprise you but as these are normally the smallest rooms in your house and generally better sealed, it is probably where you are going to experience the highest levels of CO2! But it can be improved dramatically by just leaving the bedroom door ajar or a window vent open if it is safe to do so. So, with a few simple changes you can reduce the CO2 levels that you sleep in back down to a level considered healthier.

 

What could you expect in the office at work?
600…3000 ppm- but this depends on a lot of factors. It basically boils down to the size of the room, the number of people creating CO2 and the ventilation. A key point here is that the ventilation is bringing in ‘Fresh Air’ from outside and not just circulating stale air from inside your building as this could even be contributing to the spread of airborne viruses including Covid 19! Some of these points are outside your control but you can use your portable CO2 monitor to check your working environment and try to influence improvements at work.

Your company should really have a duty of care to ensure that the working environment is suitable and safe and air quality should play a part. If you are requested to work from home, then your employer still has a duty of care to help you monitor and maintain a suitable working environment within your home. Your working environment is not just about comfy chairs, PC display, ergonomic keyboards, and suitable lighting but also the air that you breathe.

In populated environments like the office, school, gym, and restaurants CO2 Monitoring is also now being used as a further precaution against the spread of COVID-19. A report produced by Sage’s Environmental and Modelling Group (EMG) suggested that fresh air plays a significant role in keeping the virus at bay while indoors and that poor air quality could be highlighted with the use of a CO2 monitor. The report, which is backed by the Chartered Institute of Building Services Engineers (CIBSE), demonstrates the correlation between poor ventilation and an increase in the relative risk of the airborne transmission of Covid-19, and recommends that ventilation be increased wherever possible to ensure that lower levels of CO2 are maintained as this is the best indication of fresh, healthy air.

It not expensive to monitor the air that you breathe or in most cases to make the changes required to improve your wellbeing. You can get started with a portable device that you can power via a USB lead connected to your PC or laptop like the Vision CO2 Monitor at just £95 + VAT.

Or if you wanted a device that works off its own internal battery (for up to 2 years) and records all of your air quality data giving you a record of the air quality in your home, office, gym or school then you should consider the Aranet4 Home. With this model you can also view your data via your mobile phone using the Aranet4 App and Bluetooth connection. You can also monitor the min/max levels achieved during the current day and monitor your success at controlling the CO2 content of the air that you breathe. The Aranet4 Home is our most popular model that we offer at just £189 + VAT.

Aranet have also introduced a Display App. This enables you to display the measurements from your Aranet4 Home on a larger display. We have packaged the Aranet4 Home with a Tablet Display for just £299 + VAT. Now you can locate the Aranet4 Home in a suitable position for monitoring the CO2 air quality and the additional larger display in the most visible location. It is a great combination for the office, school, gym, or restaurant, in fact in any environment where people congregate and CO2 concentrations could be going beyond the levels you are comfortable with.

For further details about each device please check out the links above and if you do have any questions relating to CO2 monitoring, please do not hesitate to get in touch co2monitoring@gmciuk.com

All of the CO2 Monitors that we offer utilize the non-dispersive infrared (NDIR) sensors as suggested by the HSE. (Read the full HSE Guidance to Ventilation and air conditioning during the coronavirus (COVID-19) pandemic)