Atmospheric hazards include things such as oxygen deficiencies, dusts, chemical vapors, welding fumes, fogs, and mists that can interfere with the bodies ability to transport and utilize oxygen, or that have negative toxicological effects on the human body.
Before entry into most confined spaces, a multi-gas meter is commonly used to determine levels of oxygen, carbon monoxide, hydrogen sulfide, and the concentration of combustible gas. Other types of meters and sensors are available to detect concentration of specific gases (chlorine, sulfur dioxide, etc.) if needed.
The most common atmospheric hazards associated with confined spaces are:
Let's look at each of these types of atmospheric hazards in more detail.