Could fresh air improve productivity and reduce COVID-19 transmission within your workforce?

When outside or in a well-ventilated area, CO2 is not usually a concern to your immediate respiratory health. However, it can quickly build up in poorly ventilated spaces, such as shared offices, vehicles, pits, trenches, and other enclosed areas.

In high concentrations, exposure to carbon dioxide can be fatal. However, such concentrations are unlikely to occur during the course of a working day, unless you are working with the gas in an industrial situation, where it may be piped in or used in solid form (dry ice) as part of a process. If you are doing so, then you must have robust risk assessments in place for these activities.

Away from the immediate health hazards, however, research carried out by the Harvard T.H. Chan School of Public Health indicates that poorly ventilated buildings such as sealed office blocks may also expose workers to a higher than usual level of CO2 amongst other airborne contaminants. These contaminants can include Volatile Organic Compounds (VOCs), usually emitted by materials used in the construction and manufacture of buildings.

The study indicates that “CO2 and VOCs at levels found in conventional office buildings was associated with lower cognitive scores” and that, comparatively, those individuals within the study who were exposed to lower levels of CO2 within a well-ventilated building, saw “a significant increase in their cognitive function” over those who worked in a more conventional set-up.

The research was undertaken using a a number of different techniques, including varying the proportion of fresh air between 50% (with the remainder being made up of recirculated air from within the building), which delivered the lowest levels of cognitive ability, to 100% which, overall, produced the best results in the best results in relation in relation to cognitive ability.

In simple terms, the higher the concentration of CO2 within a workplace (from exhaled air) and the more poorly ventilated it is, the more likely it is that COVID-19 virus particles will build up within a space and be inhaled by other staff members.

The better the ventilation, the more chance that any COVID-19 particles exhaled by an infected worker may be diluted and removed from the building.

Strictly speaking, the presence of CO2 within a workplace does not indicate that a staff member may be infected. We all need to keep breathing, and CO2 is a natural by-product. However, checking the levels within your workplace using monitors can help you find the areas of your workplace that need additional ventilation.

The HSE recommends non-dispersive infrared (NDIR) CO2 monitors for use within most workplaces. Placing some of these around your workplace and checking the levels periodically will give you a good indication as to whether you need to take any action.

The monitors will measure the level of CO2 in the air in parts per million (ppm). You need to ensure that several measurements are taken throughout the day; frequently enough to reflect changes in the use of the space. For example, a kitchenette may be poorly ventilated, but if the monitor is used outside of break times it may not reflect the actual levels of CO2 when the space is busy.

According to the HSE, the levels of CO2 indicated should be used as a guide as to how well ventilated a space is and not as ‘safe thresholds’ of CO2.

For a guide, they state:

• “Outdoor levels are around 400ppm and indoors a consistent CO2 value less than 800ppm is likely to indicate that a space is well ventilated.”
• “You should take action to improve ventilation where CO2 readings are consistently higher than 1500ppm.”
• “Where there is continuous talking or singing, or high levels of physical activity (such as dancing, playing sport or exercising), providing ventilation sufficient to keep CO2 levels below 800ppm is recommended.”

With the focus on energy efficiency over the last few years, recirculation of indoor air has been employed to ensure that readily cooled or heated air is not simply vented into the atmosphere, which would waste energy.

Research emerging now, and new building certification schemes such as WELL, Fitwel and RESET, are helping to ensure that modern buildings are constructed with the wellbeing of workers in mind - in tandem with requirements to protect the environment and conserve energy.

Being such new standards, a significant number of buildings will not have been built to comply with them and as such may contain poorly ventilated spaces and recirculated air. It is worth considering that your work building may be one of them.

We can all take steps to identify poor ventilation and better ventilate our workspaces. After all, it could not only reduce the potential spread of respiratory illnesses, but it might also make your workforce healthier and more productive.