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gases need to be in the air you need to survive, would you be able to answer correctly? The correct answer is 78.08% Nitrogen, 20.95% Oxygen and the remaining .97% is made up of different shares of Argon, Carbon Dioxide, Neon, Helium, Methane and water vapor. Although Oxygen is the principal component that keeps us alive, it only accounts for less than a quarter of what is in our air and our bodies only process 4 — 5% of the oxygen that we breathe. We know this because our exhaled air Is comprised of approximately 16 —17% oxygen. . There is no doubt about it, we need oxygen to live. The definition of a confined space is: "any space that has a limited means of entry.and exit; can be bodily entered to perform work and is not meant for continuous human occupancy." Let's talk about the atmosphere for a minute. Most manholes are confined spaces. Once the lid is closed, the breathable atmosphere in the space begins to deteriorate. This happens because there is no supply of fresh air from the rest of our atmosphere and because of rust. Yes, rust. Rust, or oxidation, occurs when metallic objects begin to decay. Duringthis process Oxygen is required for the chemical reaction that causes rust to occur. With no fresh air supply, once all the Oxygen in the space is used up on rusting metallic objects, the atmosphere becomes toxic for human beings. Remember the Hydrogen Sulfide? This is one of the byproducts of the decay of plant and animal matter and many times, especially in manholes with only a gravel bottom, can infiltrate a manhole overtime and accumulate. Getting pretty scary eh? If we did not know how to deal with these hazards it would be scary. Standard procedures will either make a space like the one we just described safe to work in or tell us that supplied air will be necessary in order to enter the space. a Permit and Non- Permit Confined Spaces —A permit is required when there is adequate reason to believe that a hazardous "atmosphere" will exist or at least a reasonable belief that hazards can develop while employees are in the space: Required Equipment—For non-permit required and "alternate procedure entry" confined space work, the following equipment, as a minimum, must be utilized: o Calibrated air monitor capable of detecting: ■ Oxygen and percentage with alarms at>19.5% and <23.5% • Carbon Monoxide with alarm at 50 Parts Per Million n Hydrogen Sulfide at 10 Parts Per Million ■ Combustible gases at 10% of the Lower Explosive Limit (LEL) o Air blower i