A confined space is considered hazardous when oxygen levels are below what percentage?

A confined space is considered hazardous when the oxygen level falls below 19.5 percent. This is the threshold established by safety regulations to ensure that environments where workers may enter have adequate oxygen levels to support life. An oxygen concentration below this percentage indicates a potentially unsafe atmosphere for human occupants, leading to risks of suffocation or other serious health issues.

In normal atmospheric conditions, oxygen makes up approximately 21 percent of the air. Levels below 19.5 percent may not only affect physical performance and cognition but can also lead to unconsciousness or even fatality if not addressed promptly.

It is crucial for regulations to define specific thresholds to help keep workers safe in environments that might present risks due to confined space characteristics, such as limited airflow, contaminants, or other hazards. Therefore, understanding and adhering to these safety standards is essential for anyone working in or around confined spaces.