A permit-required confined space is defined as containing or having the potential to contain what?

A permit-required confined space is specifically defined by the presence of a hazardous atmosphere. This includes environments that can expose workers to toxic gases, insufficient oxygen levels, or flammable vapors. The key factor that necessitates a permit is the potential for these dangerous conditions, which can arise from various sources such as chemicals, biological agents, or other environmental factors within the space.

While hazardous materials, excessive heat, and heavy machinery can contribute to hazards within confined spaces, they do not encompass the definitive criteria set out in regulations. The focus on hazardous atmospheres is central because it directly impacts air quality and worker safety, creating a pressing need for permits, monitoring, and precautions before entry into such spaces.