Question: what is the percentage of carbon dioxide that is considered dangerous in the environment?
Answer: At levels 17 percent or below, your mental abilities become impaired. In a sealed environment, as oxygen levels drop from 21% to 17%, the CO2 level will rise to 4%. This level of CO2 can result in symptoms like dizziness, asphyxiation, confusion, fatigue, vertigo, headaches, tinnitus, and even seizures.