According to OSHA, what is the minimum acceptable oxygen level for humans in the workplace?

The minimum acceptable oxygen level for humans in the workplace, as established by OSHA, is 19.5%. This standard is crucial because oxygen concentration below this level can pose serious health risks, such as impaired cognitive function, reduced physical ability, and even asphyxiation in extreme cases. Generally, normal atmospheric oxygen levels are around 21%. OSHA sets the minimum at 19.5% to ensure that workers are in a safe environment where they can maintain their health and performance standards.

The other options exceed the minimum acceptable level, creating a buffer that ensures safety in various working conditions, but they do not establish the legally mandated threshold where safety practices kick in to protect workers from low oxygen levels. Thus, having a standard of 19.5% is significant for ensuring adequate safety protocols in the workplace.