What is a CO2 meter for and why do they recommend its use indoors?
With the announced return to classes for August 30, by the SEP, as well as the gradual return to activities in various states of the Republic, it is common to hear on networks and specialized pages that experts draw attention to this artifact, the CO2 meter, which monitors and alerts with a light signal when a closed space does not have good air quality.
For a safe return to school, Our analyst Pamela Cerdeira draws attention to the use of having a CO2 meter in the classroom as an option as well as other instruments that guarantee or allow adequate ventilation in the classrooms.
Why is it necessary to measure the air quality of a place?
Although the CO2 meter does not calculate COVID-19 viruses, it can detect when there is poor air quality in a place and there is an increased risk of contagion by aerosols. This device is very useful for measuring air quality, especially if there were someone asymptomatic or sick with coronavirus in that place who had spread their aerosols in the place.
We must not forget that COVID-19, according to what experts point out, is breathed, either by droplets - at short distances - or by aerosols - at long distances - hence it is also widely recommended to ventilate closed spaces. .
What is a CO2 meter?
In recent days, the Government of Querétaro informed its inhabitants, through its official newspaper Arteaga's shadow that due to the increase in the number of cases they were in scenario B and for this reason some measures came into force to try to contain the situation. What mainly stood out was the use of a CO2 meter and thus measuring the amount of this gas in closed places.
The CO2 meter is a device that detects carbon dioxide - the gas that we eliminate during daily breathing - in closed environments and tells us when there is a need to ventilate that area.
What countries and states recommend the use of CO2 meters?
In addition to Japan, some countries in Europe (Germany, Belgium, Spain, Switzerland), South America (Chile, Colombia, Argentina) as well as in certain states of the Mexican Republic (Querétaro, Quintana Roo, Chihuahua, to mention a few) are recommending ventilate the interiors as well as the use of a CO2 meter.
For example, in Argentina the Federal Council of Education (CFE) presented a Guide for educational institutions. Conditions and recommendations for living in the school which details the CO2 measurements in the classroom, the permitted levels and when it should be ventilated. This official brochure recommends that classes should be held outdoors or on terraces to minimize the risks of contagion. By clicking on this link you can consult the Guide.
What are the permitted levels of CO2 indoors and outdoors?
Although a CO2 monitor, by itself, cannot determine if the SARS-COV-2 virus is present in a space, it can monitor and alert when a space exceeds the permitted CO2 levels, as this could increase the risk. of contagion if anyone present has coronavirus.
Based on the Guide for classroom ventilation, in Spain and the Harvard University Guide, the Querétaro government strategy points out that “CO2 meters are relatively affordable and easy-to-use instruments that measure the levels of carbon dioxide in the environment, which is one of the predominant substances indoors or in closed places, coming from the respiration of living beings” .
Outdoor levels
The CO2 level of the outside air is 400 to 450 ppm (particles per million)
Acceptable levels indoors
Between 500 and 700 indoor ppm is considered acceptable
alert levels
When reaching 800 ppm it is mandatory to ventilate the room to renew the air.
Some experts consider that if CO2 levels are kept below XNUMX, the risk of contagion indoors, without neglecting face masks and healthy distancing, is reduced in places such as businesses, restaurants, theaters, public transportation and schools.
