IAQ in working environments in Belgium: alternative approaches to CO2 requirement

In March 2016 a new regulation came into force in Belgium regarding the wellbeing at work, with specific requirements on the indoor air quality (IAQ). The requirement is expressed as a maximum absolute CO2 concentration of 800 ppm in all working spaces. Compared to the previous requirement, i.e. 30 m³/h per worker, this new requirement corresponds to at least a doubling of the required ventilation flowrate. Although the advantage of this new requirement is its performance based approach (final result, in terms of CO2), this raises the question of the responsibility of the different involved persons, such as the designer, contractor and owner of the building, the employer but also the employee as end user of the building. Moreover, the stricter requirement remains an economical and technical challenge, especially for existing building without a complete ventilation system. Our work aimed to identify alternative approaches for the expression of IAQ requirements for working environments in order to maximise the final IAQ improvement for the workers while assuring an effective implementation in practice thanks to a robust compliance framework.  Beside an absolute CO2 requirement, different alternatives exist to consider also the impact of material emissions on the IAQ in working environments. The new standard FprEN16798-1:2016 has been used as a basis to identify alternative approaches. The advantages of the CO2 requirement are to be performance based and easily measurable on site. However, the CO2 requirement focuses only on the persons as source of pollutants and do not consider the possibility to control the other sources of pollutants, such as emissions from materials, by limiting them at the source (for example choosing low emitting materials). 
One of the alternative approaches is to consider the ventilation needed for the persons and that needed for material emissions separately in accordance with method 2 described in the standard. An alternative approach could be different CO2 requirements depending on the level of emission of the materials. The proposed requirements could encourage the choice of (very) low emission materials, leading to effective IAQ improvement in practice. The challenge for the future remains the characterisation of the emission levels for the building materials, but also for all other materials, products and activities in the workspace, as well as using those datapoints effectively in a robust compliance framework.