As we all know, oxygen is essential for respiration. The standard level of oxygen in the air that we breathe is 20.9%, but this figure does not need to drop significantly before adverse effects begin to appear.
Some physiological effects start to appear at an oxygen concentration of 19%, but these are not always noticeable. Thinking becomes impaired between 15 and 19%, as does coordination. This reduction in cognitive abilities can be potentially fatal to the ability to make judgments and rational decisions but can occur entirely without individuals noticing.
As the oxygen level decreases further, to between 12-15%, the individual will experience poor judgment and abnormal fatigue, which will worsen as the levels continue to fall to 10%. The person may faint after just a few minutes at such a low saturation.
Should levels drop below 10%, the average person is likely to experience an inability to move, followed by loss of consciousness and convulsions, which could result in death in as quickly as just nine minutes.
It is important to consider where an oxygen-depleted atmosphere might occur. Oxygen deficiency can be caused for a variety of reasons but usually occurs in an enclosed space. Wherever there is a volume of gas (i.e., in a pipeline or a tank), leaks can quickly displace the oxygen and fill the enclosed space.
Decomposition of organic matter can be another cause: plant or waste material, for instance, emits carbon dioxide, carbon monoxide and potentially hydrogen sulfide. Each of these emitted gases displaces the oxygen and can, in some cases, react with the oxygen, which results in an oxygen-deficient environment.
The definition of a ‘confined space,’ according to the Health and Safety Executive (HSE), is as follows: “A place which is substantially enclosed (though not always completely) and where serious injury can occur from hazardous substances or conditions within the space or nearby (e.g., for instance, a lack of oxygen).”
It would seem likely then that a room or laboratory would not require an oxygen monitor, as the scope of the definition appears to refer to only smaller or more enclosed spaces. However, a room oxygen monitor would be required in certain scenarios: consider, for instance, a cryogenic lab, in which the freezers typically contain many liters of liquid nitrogen.
Therefore, it is not difficult to imagine how a leak could quickly displace the oxygen within a room, given that liquid nitrogen expands by 694 times upon evaporation, which would render the space deadly.
The Occupational Health and Safety Administration (known as OSHA) regulations thus require the fitting of oxygen deficiency monitors in any room where compressed gases are used or stored.
When functioning correctly, oxygen monitors measure the oxygen concentration within the room, sounding an alarm if the level dips below 19.5 percent. It is important to regularly function test and calibrate at the prescribed interval period, particularly as every gas detector is only as good as its last calibration.
In order to ensure that this calibration is as accurate as possible, Air Products offers the highest-quality calibration gas on the market today. Air Products offers lightweight canisters of all common calibration gases, which can be ready for immediate dispatch on purchase. Visit the Air Products site for more information today.
This information has been sourced, reviewed and adapted from materials provided by Air Products PLC.
For more information on this source, please visit Air Products PLC.