Oxygen safety is critical for stored oxygen gas used in medical and industrial applications as well as other oxygen enriched environments. Oxygen safety systems are an integrated collection of gas sensors, real-time displays, strobe lights, audible alarms, posted notices and training materials all combined to protect employees who work in potentially oxygen deficient or enriched areas.
However, the ability to store oxygen as either a gas or a liquid requires extreme caution. In addition to the inherent safety issues with high pressure containers, too much oxygen can be just as dangerous as too little oxygen.
Conversely, oxygen safety systems are important where other compressed gases are stored. Any compressed gas released in an enclosed area can quickly lower the oxygen level and inhibit breathing.
Compressed Oxygen Safety
Compressed oxygen in portable cylinders is used in a variety of industrial and medical applications. What each of these applications have in common is that the cylinders are designed to provide a safe and convenient way to transport and use the gas.
A convenient way to tell if a cylinder is filled with oxygen is that the cylinder markings will always be green and a label should be affixed notating the gas stored inside the cylinder.
Industrial Oxygen Cylinders are available in standard sizes rated by the capacity of compressed gas they hold. For industrial applications like welding the most common sizes are: T (approximately 300 cu ft.), K (200 cu ft.) and S (125 cu ft.). These are the cylinders you most often see in garages, although several other sizes are available. While the thickness of the walls of these cylinders makes them safe containers, their weak points are the neck where the regulator attaches, and the metal fatigues from age.
Best practices for the handling and use of oxygen cylinders include:
- Store upright with restraints in well-ventilated areas
- Do not use force when opening or closing the valves
- Keep away from sources of ignition
- Have the tanks inspected each time they are refilled
For more information, the Occupational Safety and Health Administration (OSHA) has specific best practices for the safe use of oxygen during gas welding and cutting.
Medical Oxygen Cylinders are smaller, more portable, and hold high-purity medical-grade oxygen for personal use. Like industrial cylinders, these also have a letter designation for size like D (14 cu ft. or E (25 cu ft.). While the same best practices for storage and safety for all oxygen cylinders apply to medical oxygen, the biggest concern is fire. For example, it is dangerous to use medical oxygen near open flame like a gas stove or when using a cigarette lighter.
Liquid Oxygen Safety
Liquid oxygen (LOx) is the name for oxygen gas molecules compressed to a point where they enter a liquid state. During compression the liquid oxygen reaches temperatures of -297°F (-183°C) and becomes a cryogenic gas. Because of the high pressure and super-cold temperatures, liquid oxygen is dangerous to handle.
High Pressure – LOx tanks are designed to high standards and equipped with pressure-relief valves to control internal pressure. Under normal conditions these containers will periodically vent product. Best practices include storing LOx tanks in rooms with proper ventilation and not plugging or tampering with the pressure-relief valves.
Cold Temperature – Liquid oxygen will immediately freeze anything it comes in contact with. Like “freezer burn” contact will instantly destroy skin cells. Materials like plastics become brittle and can be shattered. Best practices include wearing protective eyewear and a face shield, thermal insulated gloves and loose-fitting clothing covering the entire body. Anything worn that comes in contact with LOx should be immediately removed.
Fire - Liquid oxygen has an expansion ratio of 860:1. This means that as it changes from a liquid to a gas it expands to 860 times its volume. This can raise the oxygen level in an enclosed area quickly, which also makes it a fire hazard. In a room with only a 2% increase in oxygen levels, even a small spark can result in an explosion. In areas where high levels of oxygen may be present, best practices include only handling it in a well-ventilated area, immediately removing any clothing splashed with liquid oxygen.
In addition, CO2Meter holds a valued partnership with the Compressed Gas Association (CGA) who recently published supplemental guidelines for the safe handling of cryogenic and refrigerated liquids. For more information click here.
Low Oxygen Safety Systems
All living things require oxygen. While too much oxygen can be tolerated for short periods of time, low oxygen levels can lead to death in minutes.
The effects of oxygen deprivation are well known. Within seconds after oxygen ceases to enter the lungs, hypoxemia (low oxygen in blood) and hypoxia (low oxygen in tissues) begins to occur.
The most immediate problem occurs in the brain. Within seconds hypoxemia results in confusion followed by unconsciousness. Irreversible damage to the brain begins in minutes.
Oxygen deprivation as the result of suffocation is a real issue, especially for children. According to a study published by the US National Library of Medicine, about half of the sample who were injured from suffocation were children, who also had higher mortality rates than the general population.
Best practices for reducing the chance for suffocation include removing doors from old refrigerators, removing access to items like toys or plastic bags, and careful supervision in the water or when bathing. Sudden Infant Death Syndrome (SIDS) has also been linked to suffocation. This website from the National Institute of Health has several recommendations for reducing accidental suffocation or strangulation in bed.
In medical, scientific or industrial areas where other gases besides oxygen are stored, a leak in the gas delivery system in an enclosed area can create a potential for suffocation. In these cases, best practices include warning signs, proper ventilation and the use of oxygen depletion or enrichment safety systems and alarms.
These devices are available to protect staff in enclosed areas near storage of nitrogen, argon, ammonia, chlorine, propane, nitrous oxide, helium, argon, and other inert gases.
For more information on choosing the right monitoring solution for your application or for additional resources, please email us at Sales@COMeter.com.