At what oxygen level is a confined space considered oxygen deficient?

A confined space is considered oxygen deficient when the oxygen level falls below 19.5%. This standard is established to ensure safety in environments where people may work or enter. Normal atmospheric oxygen levels are approximately 20.9%. Levels dropping below 19.5% can lead to symptoms of hypoxia, including confusion, impaired coordination, and, in severe cases, loss of consciousness or death. This threshold is crucial for the safety protocols used by public works managers and the guidelines followed during operations in confined spaces, making it essential knowledge for anyone responsible for managing such environments.