What is the typical range of oxygen concentration in a confined space?

The typical range of oxygen concentration in a confined space is critical for ensuring the safety and health of individuals working in or entering those environments. The correct range, 19.5% to 22.0%, reflects the levels at which oxygen is sufficient for human respiration while also accounting for potential variations that may occur due to various factors, such as the presence of other gases or changes in atmospheric conditions.

Oxygen concentrations below 19.5% may indicate a potentially hazardous environment, as lower levels can lead to symptoms of oxygen deficiency, including dizziness, shortness of breath, and impaired cognitive function. Conversely, oxygen concentrations above 22.0% can increase the risk of fire and explosive reactions, especially in the presence of combustible materials.

As for other ranges provided in the options, they either extend beyond safe thresholds for oxygen levels or do not accurately reflect the typical safe working ranges recognized by safety standards. Understanding these concentrations is essential for anyone involved in safety protocols in confined spaces, as it helps guide monitoring and emergency response efforts effectively.