Can you stay without oxygen if you get in a small room with many people?
When you spend many hours stuck in a room with many people, and has the door and windows closed, it can make you feel claustrophobic, and even it sometimes causes you to breathe heavily with trouble. But could you really run out of oxygen in this context or is it possible because there is always enough air that enters through the cracks of the room?
The short answer is no. But with nuances.
A person , on an average, needs between 10 and 50 litres of oxygen per hour. In a room of 20 square meters there are about 10,000 liters of oxygen. I.e., that if we want the oxygen to run out I will have to be locked up many hours,even days , depending on the people who join us.
But, in spite of this,the air may feel stuffy as time passes and we need to aerate the room to fight the oppression. In this case we are not suffering shortage of oxygen, but excess of other substances: carbon dioxide and volatile organic compounds (VOC).
Carbon dioxide is the gas that we expel when we breathe, and in high concentrations, it can have a narcotic effect. This phenomenon is explained in the book ‘70 curious questions about the world that surrounds us‘, edited by Martin Gent.
In a room with good quality air, the proportion of carbon dioxide does not exceed 0.1%. But in a room without ventilation, CO2 can be higher within an hour approximately. Volatile organic compounds come from beams, carpet, etc. In extreme cases this situation can lead to headaches or dizziness, or simply sleep. If we continue in a room of 20 square meters, and we assume that there are ten participants, air should renew completely every hour and a half to prevent an increase in the carbon dioxide and VOCs and keep the oxygen levels at safe point.