Carbon Dioxide
- Sources
- Impacts
- Testing
Sources
Sources of Carbon Dioxide (CO2)
Carbon dioxide is a colourless, tasteless, odourless gas that is naturally present within the Earth’s atmosphere. It is produced by all living organisms including humans. It can also be produced by forest fires and volcanos. Anthropogenic sources most famously involve the combustion of fossil fuels, contributing as a major greenhouse gas.
CO2 has a plethora of uses including fizzy drink carbonation, dry ice, preservative, refrigerant and is used in fire extinguishers. Carbon dioxide is constantly moving through the environment via the natural carbon cycle. Exposure to high levels of CO2 above ambient levels is likely a result of occupational exposure, in places such as factories and food processing plants.
Measuring levels of CO2 within indoor spaces is an excellent metric to determine occupancy within a building (indoor CO2 levels are largely a result of human respiration). Poor ventilation and indoor combustion can also cause CO2 build up within an indoor space.
Typical Sources of CO2
- Human Respiration
- Natural Carbon Cycle
- Fossil Fuel Burning
- Indoor Combustion
Impacts
Impacts of Carbon Dioxide (CO2)
Low levels of CO2 exposure do not cause adverse health effects. Higher levels of exposure within indoor spaces can cause confusion and low concentration, with increasing levels causing headaches, dizziness, sweating, muscle twitches, increased breathing rate, shortness of breath, drowsiness, fast heart rate and loss of consciousness.
Extreme levels can cause asphyxiation and death. High CO2 levels altering focus may be a cause for concern in typical work spaces such as the office floor, and may contribute to sick building syndrome.
Common Impacts of CO2
- Loss of Concentration
- Headaches
- Drowsiness
- Asphyxiation
Testing
Testing for Carbon Dioxide
Testing for carbon dioxide can be performed by use of the Temtop M2000, which gives point in time readings for CO2 levels. Awair and aranet air sensors, (as well as a plethora of other commercial air sensors) can provide continuous readings of CO2 levels to provide longitudinal data to aid potential solutions towards ventilation characteristics.- Point In Time Readings with Temtop 2000
- Awair & Aranet Air Sensors
Outdoor air typically has ~400 ppm of CO2. Indoor spaces have ~400-1000 PPM of CO2. 1000 PPM + are when initial symptoms of drowsiness and poor focus start to manifest, due to reduced oxygen to the brain. Anything below 1000 PPM is considered good indoor air quality.
Ideal air quality would be below 600 PPM.
Around 40,000 PPM of CO2 is when death can occur due to CO2 acting as an asphyxiant.
Commonly CO2 levels are used to infer poor ventilation. CO2 levels consistently higher than 1500 ppm in an occupied room indicate poor ventilation. The EH40/2005 limit for CO2 is 5000 PPM, but this would not be acceptable for ambient indoor air.
- There is a lack of standardised limit in legislation, but it understood that below 1000 PPM of CO2 is a good level of air quality.
Carbon Dioxide FAQs
How Do I Remove CO2 From My Indoor Air? ↓
CO2 is commonly measured to infer ventilation effectiveness. Low levels of CO2 in enclosed busy spaces likely mean ventilation systems are working well. To remove CO2, ensure ventilation system is maintained and effective. Filters are not needed to remove CO2, as concentrations are lower in outdoor air so this air is extracted to indoor spaces.
Why Are There No Set Standards for CO2 Limits ↓
Direct health impacts from lower concentrations of CO2 itself are not definitively established. CO2 being an indicator of ventilation efficacy, it can be seen that lowering CO2 could correlate with the reducing of spreading disease by respiratory pathogens, like COVID-19. Therefore, CO2 limits are not necessarily a result of direct CO2 health impacts, rather what other metrics correlate in parallel.
What Environments Are Typical for Increased CO2 Exposure ↓
Indoor areas with high occupancy and poor ventilation such as aircraft cabins, offices, classrooms. Areas such as this which also have combustion appliances used inside is common in developing countries. Working in confined spaces for long periods.
Can I Perceive CO2 ↓
In What Industries May People Be Exposed to High Levels of CO2? ↓
Working with dry Ice. Working in breweries. Working in cold storage facilities. Ethanol production. Greenhouses.
Why Choose ARM?
CO₂ monitoring is essential for assessing ventilation and occupant wellbeing. ARM delivers continuous monitoring and actionable reporting.
We are SafeContractor certified and a BESA member. Our CEO Adam Taylor chairs the BESA Indoor Air Quality Group, ensuring our insights are aligned with national guidance and ideal for workspaces, schools, healthcare, and high-occupancy areas.
