Pressurized Gas is Everywhere

CO2Meter has long been recognized for the Remote Oxygen Depletion Safety Alarm which provides warning for staff before they enter an area with dangerously low oxygen levels caused by pressurized gas leaks.

Pressurizing a gas in a tank or a cylinder provides a convenient way to transport and store it. Flower shops use cylinders of helium to fill balloons. Restaurants use tanks of carbon dioxide to carbonate soda. Outdoor grills use propane to cook your steaks. What these all have in common is that under pressure, the gas becomes a liquid.

Pressurized gases are used in many industries:

• CO2: Restaurants, Breweries, Wineries
• Nitrogen: Food Packaging
• Argon, helium, CO2: Welding
• Oxygen: Hospitals, Medical
• Tetrafluoroethene, CO2: Refrigeration
• Helium: Cryogenics and IVF Facilities

Recently, The College of American Pathologists, (CAP)  detailed new requirements which pinpoint the potential hazards related to using and storing liquid nitrogen (LN2) and dry ice.

These requirements apply to the laboratories, clinics, and reproductive facilities to ensure safety in regards to oxygen deprivation - which the college encountered in a deadly incident in 2017. 

The Dangers of Pressurized Gas

Cryogenic fluids are a special sub-set of pressurized gases. Cryogenics is the science of very low temperatures. In general, all temperatures below 120 Kelvin (-244°F or -153°C) are considered cryogenic.

At these temperatures, nitrogen, oxygen, helium, methane, ethane and argon all become liquids. Thermopeida lists some of the most common cryogenic fluids.

As refrigerants, cryogenic liquids are useful in modern science. For example, at the Large Hadron Collider at CERN, they enable the superconducting operation of beam positioning devices with liquid helium at 4K, or -452°F.

With the exception of oxygen, all the gases are asphyxiates. An asphyxiate gas is a nontoxic or minimally toxic gas which reduces or displaces the normal oxygen concentration in breathing air. Breathing of oxygen-depleted air can lead to death by asphyxiation, or suffocation. (Wikipedia)

Small amounts of any pressurized gas are not harmful. However, a leak in a pressurized gas tank, line or fixture can easily become dangerous. For example, one volume of liquid nitrogen at its boiling temperature vaporizes to 696.5 volumes of nitrogen gas at room temperature. For most common gases the expansion ratio from liquid to gas is between 700 and 900. This means that even a small leak can quickly lower the oxygen level in an enclosed room or area.

Mitigating the Risk

To solve this problem, some facilities depend on personal oxygen monitors. These are useful in normal operations. But what happens if the oxygen level is reduced overnight? By the time a personal alarm sounds, they may not be able to leave the room.

Another challenge is that people can make mistakes. No matter how much training they receive, eventually someone will walk into a potentially hazardous situation without an oxygen monitor.

Our Oxygen Deficiency Alarm solves these problems. By remotely monitoring for oxygen levels in real time, staff will be warned before they enter an area. In addition, the alarm can control ventilation fans or can be connected to a facility’s HVAC and/or alarm systems.

What About too much Oxygen?

Tanks of liquid oxygen can also be a risk. Breathing oxygen at pressures of 0.5 bar or more (roughly two and a half times normal) for more than 16 hours can lead to irreversible lung damage and, eventually, death. Above 60% concentration, oxygen becomes an asphyxiate. However, even at levels above normal air (20.95%) oxygen is dangerous because it acts as an oxidizing agent. Combined with heat and fuel, oxygen promotes fire.