могу еще такую скинуть

а вот что пишут по этому поводу ученые а не маркетологи: It should be noted that CO2 is not generally considered as a health hazard at the concentrations that typically occur in nonindustrial indoor environments. Exposure limits for CO2 established by agencies associated with safety and healthy working conditions, e.g. National Institute for Occupational Safety and Health (NIOSH) from USA, are 5000 ppm for time weighted average (average exposure on the basis of an 8-hour day and a 40-hour workweek) and 30 000 ppm for short-term exposure limit (time weighted average exposure that should not be exceeded at any time during a workday) [9]. Similar threshold values are provided by European regulations (e.g. [10]. Adverse health effects have not been observed below the level of 7000-10000 ppm during prolonged exposure to CO2 and below 20 000-30 000 ppm by short-term exposure [5], [11], [12], [13]. Some investigations showed an association between elevated indoor CO2 levels (1000-4000 ppm) and increases in SBS symptoms. Nevertheless, no direct link between exposure to CO2 and SBS symptoms was found – only the correlation with other indoor pollutants that may cause adverse effects was suggested https://www.sciencedirect.com/science/article/pii/S1877705813007558