Hmmm.
Sounds like an really expensive air handling system accessory. I do not have any experience with that. I cannot believe there is a law governing it in a school. However, CO2 displaces oxygen and is an asphyxiate at high concentrations. It would signal a sign of a problem with the HVAC not venting its exhaust gases properly. Here is a chart:
The levels of CO2 in the air and potential health problems are:
* 250 - 350 ppm – background (normal) outdoor air level
* 350- 1,000 ppm - typical level found in occupied spaces with good air exchange.
* 1,000 – 2,000 ppm - level associated with complaints of drowsiness and poor air.
* 2,000 – 5,000 ppm – level associated with headaches, sleepiness, and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate and slight nausea may also be present.
* >5,000 ppm – Exposure may lead to serious oxygen deprivation resulting in permanent brain damage, coma and even death. This is why there are abort switches on CO2 Total flooding systems. Typically used in large engine rooms on ships. They are fun to watch discharge!!!