Nitrogen Tank or Cryogenic Dewar? Not Sure Where they are Installed? Here’s the List!


Liquid nitrogen is used in a broad range of industries, from steelmaking and pharmaceutical to health care and ceramics. The inert gas is also used in laboratories, breweries, fine cooking, and more. Wherever liquid nitrogen is used, it must be stored securely so as not to mingle with air. Learn why nitrogen must be so carefully contained and where and how N2 gas is stored.

Bulk Nitrogen Tank Storage 

Liquid nitrogen is stored in a bulk nitrogen tank, also known as a nitrogen dewar. Nitrogen dewars exist wherever nitrogen is used, including in:

  • Labs
  • Research universities
  • Restaurants, bars, and hotels
  • Freezers
  • Hospitals
  • Flash freezing facilities
  • Food processing facilities
  • Cryotherapy facilities
  • Manufacturing plants

The nitrogen dewar features a vacuum stopper, which protects the substance inside and prevents the nitrogen from boiling off. Dewars must have pressure release valves to prevent a bulk nitrogen tank explosion, which can occur when pressure builds up inside the tank. Since liquid nitrogen vaporizes at room temperature, it’s critical that the tank stay sealed at all times.

Nitrogen and other insert gases, including argon, displace air when they are released into the environment. As oxygen is displaced, the air becomes oxygen deficient. Breathing oxygen deficient air causes respiratory distress and death via asphyxiation. Since nitrogen is colorless and odorless, there is no way to tell that a leak occurs unless you use an oxygen monitor, which samples oxygen levels.

Given the risks posed by the material, bulk nitrogen tanks must be stored and transported safely and securely. Workers must bleed out pressure before transporting the tanks, for example, to reduce the risk of incident during transport.

A robust ventilation system should be installed where the nitrogen is kept, so escaped nitrogen can be vented away, and fresh air should be circulated into the storage room several times per hour.

Other safety measures include checking that fittings are appropriate, wearing gloves to prevent the nitrogen from burning the skin, and never filling dewars more than 80 percent full.

While liquid nitrogen can be transferred from the bulk nitrogen tank into a smaller tank for small scale use, it must only be transferred into approved container. If you use the wrong container, it could shatter, leaking nitrogen into the air and decreasing available oxygen.

Wherever nitrogen is stored or used, signs warning of the risks associated with the material should be posted as a warning to employees. When working with nitrogen, staff should wear eye protection, cryogenic gloves, and other safety equipment.

Anyone who handles or works with the gas should be trained in safe use, storage, and handling of bulk nitrogen tanks as well. The valves, gauges, and other components of the nitrogen storage tank should be inspected regularly for safety, and replaced whenever you notice wear and tear.

Why You Need an Oxygen Monitor Where Nitrogen is Stored

By placing an oxygen monitor wherever nitrogen is used, you can protect worker safety and prevent injury or fatality onsite. Oxygen monitors continually sample oxygen levels in the room, making sure that oxygen falls within acceptable levels. Should nitrogen gas leak from the dewar, ambient oxygen levels will start to tumble as the air is displaced by nitrogen.

When oxygen levels fall to the threshold set by OSHA, which is 19.5 percent, the oxygen deficiency monitor will sound and flash alarms to notify workers onsite. Staff can exit the room before they begin to experience the adverse effects of being in an oxygen deficient atmosphere, then call 911 so emergency personnel can respond to the threat.

PureAire offers a robust oxygen deficiency monitor capable of withstanding low temperatures of -40 Celsius. Once installed, the oxygen monitor works as intended for 10+ years with no annual maintenance or calibration. An ultra-loud alarm is audible throughout the premises, while a flashing light provides a secondary alert for employees. The unit easily mounts on the wall with brackets and comes with a 3-year warranty. Learn more about oxygen monitors from PureAire at

Posted in Uncategorized | Tagged , , , , , , , , , | Leave a comment

Oxygen Monitors now Required for Nitrogen, Argon, Helium, and CO2 use in Denver


The Colorado city of Denver recently passed a new law that requires facilities that use insert gas to install oxygen deficiency monitors wherever these gases are used in excess of 100 pounds. Learn what the new law requires from businesses and how an oxygen sensor protects your employees, your business, and your peace of mind.

What Denver’s New Law Requires

The law specifically applies to Colorado commercial, industrial, or manufacturing facilities that use inert gases, including nitrogen, argon, carbon dioxide, and helium. Facilities covered by the new law include water treatment plants, laboratories, and food processing plants.

Fire suppression systems and medical gas systems are not covered by the Denver law.

Under the new law:

  • Inert gas storage tanks must be placed in approved locations, whether stored inside or outside of the building
  • Storage containers must be secured to prevent tip-overs
  • All valves and tubing used with the gas system must meet applicable standards
  • Gases must vent outside the building
  • All areas where gas is used must either have an oxygen deficiency monitor or continuous ventilation system, which keeps the oxygen levels in the room steady
  • Oxygen alarms should be visually inspected daily by trained staff members
  •  Storage tanks, piping, and other parts of the system must be checked on a monthly basis
  • Tests of the system must be conducted regularly with either air or an inert gas

The Denver law sets out regulations for the type of oxygen deficiency monitor, plus where and how to use them. Acceptable monitors must be installed in any location where an inert gas leak could result in an oxygen deficient environment where public health could be at stake.

Oxygen detectors must be on an approved device list and directly connected to the electrical supply and fire alarm system for the site. The oxygen detectors must be permanently mounted to the wall at a height which is consistent with the given gas’s vapor density, so they can work properly. The devices must be located within their specified ranges of operation, in order to ensure the monitors can work as intended.

The law prohibits self-zeroing or auto calibrating devices, unless they can be spanned or zeroed to check that the oxygen monitor is working as it should be. All installed oxygen monitors must be calibrated regularly to ensure safe and reliable operation.

Alongside mounted alarms, companies must place signage that notifies employees of the oxygen monitor and gives instructions for what to do in the event of an alarm. Typical instructions tell staff to leave the building and call 911 if the alarm is going off.

Signs notifying employees of the risk for oxygen deficiency must be posted anywhere inert gas is stored or used.

To further protect employees, the Denver law mandates that gas be transported, filled, or moved only by qualified individuals who follow protocol. All equipment, including piping systems, must be inspected for competency and the organization must maintain records for a period of three years.

Why an Oxygen Monitor is a Practical Suggestion

Oxygen deficient environments occur when an inert gas, such as helium, nitrogen, or argon, escapes into the environment and begins to displace oxygen. Since these gases have no odor or color, there is no way that staff working in the room can tell something is leaking. As the oxygen levels fall, employees can experience confusion and respiratory distress, resulting in death by asphyxiation.

An oxygen monitor tracks ambient levels of oxygen and sets off an alarm when oxygen levels fall below the safe threshold, thus protecting employee safety. Since employees can both hear and see the alarm, they will know there is a problem even if they are operating loud equipment that overrides the noise of the sensor.

Oxygen monitors are simple solutions to pressing problems faced by organizations that rely on inert gases and want to mitigate their risk.

PureAire’s oxygen sensors are cost-efficient and high quality. They are designed with a zirconium sensor, which is capable of lasting for as long as 10 years. PureAire’s oxygen sensor is accurate in diverse environments, from storage freezers to basements. The sensor functions between -40 and 55 C. While PureAire’s oxygen monitors do not need to be calibrated, they are capable of calibration, thus eligible for use in Denver.

PureAire’s monitors need little maintenance to work reliably once they are installed using the included wall-mounting brackets, and they are not affected by changes in the barometric pressure, a known problem with other types of oxygen sensors. PureAire’s products can be set to measure oxygen levels of either 18 percent or 19.5 percent (which is the OSHA action level), to comply with standards.

To learn more about oxygen monitors from PureAire, and view specifications, go to


Posted in Uncategorized | Tagged , , , , , , , , , , | Leave a comment

Storing Liquid Nitrogen in Laboratories: Which Safety Precautions and Sensors Will Protect your Employees?


Liquid nitrogen is frequently used in scientific research, chemistry classes, and even culinary arts nowadays. The substance is safe when properly stored, and as long as everyone follows safety protocols while handling the liquid nitrogen. As part of an environmental health and safety review (EHS review), learn safety considerations regarding storing liquid nitrogen in the lab setting.

EHS Review: Understand Liquid Nitrogen Risks

Liquid nitrogen is known for its cryogenic properties. It can freeze things incredibly quickly. This property also applies to people, so staff must take safety precautions when handling liquid nitrogen. Even seconds of exposure can damage skin and eye tissue, and may cause frostbite.

Staff should never transport liquid nitrogen in open containers. They should never reach directly into vats of the substance.

The main health risk with liquid nitrogen occurs when the liquid vaporizes into gas, which happens if it leaks into the atmosphere. Nitrogen expands in volume when it turns into gas, and depletes oxygen from the air. The gas has no odor or color, so there is no way staff can tell a leak has occurred without an alarm system. If a nitrogen leak occurs, oxygen levels will fall below safe thresholds. This causes severe cognitive and respiratory problems, as well as death by asphyxiation.

Liquid nitrogen, like other cryogenic liquids, needs a pressure-relief valve during storage. Without such a valve, internal pressure could cause the storage tank to explode. Liquid nitrogen should be stored in a room that has proper ventilation as a precaution around leaks. If a leak occurs, the ventilation system can help shunt gases outdoors, protecting the health of workers.

How to Protect Your Employees’ Environmental Health and Safety With an Oxygen Monitor TX-1100DRA_01_24

Facilities must install, calibrate, and maintain oxygen sensors to comply with safety policies regarding the storage of liquid nitrogen in the lab setting. These units act as a secondary precaution against the dangers of a nitrogen leak. An oxygen deficiency monitor or O2 sensor measures the levels of oxygen in the environment at all times. These devices provide labs with a cost-effective and reliable way to make sure there are no leaks in nitrogen storage areas.

For safety precautions, install one oxygen deficiency monitor anywhere liquid nitrogen is stored, handled, or used. These monitors mount to the wall quickly and provide continuous sampling of oxygen levels. As long as there is no leak, and the room contains enough oxygen, the monitors stay silent. If nitrogen leaked it would cause a decline in oxygen levels, eventually triggering an alarm and flashing light. The oxygen monitor would provide enough time for anyone working in the area to vacate the premises and avoid being harmed or killed.

While there are several styles of O2 sensor on the market, those from PureAire are preferred for their high quality and cost efficiency. PureAire’s O2 sensors feature zirconium, which lasts for 10+ years on average with no maintenance and no calibration. Once the monitor in installed, there’s nothing more that needs to be done. Since PureAire’s oxygen monitors are reliable once installed, and require less maintenance than the competition, they make it easier and cheaper for labs to protect worker safety. Learn more about PureAire’s products by visiting

liquid nitrogen, oxygen monitor, Oxygen deficiency Monitor, ln2, nitrogen, ehs, environmental health and safety, O2 deficiency monitor

Posted in Uncategorized | Tagged , , , , , , , | Leave a comment

Titanium Demand on Rise for Additive Manufacturing Printing: How it’s Made? Titanium Plasma Atomization.

Link to oxygen sensors

Plasma atomization is used in many applications, including 3D printing. First developed in 1998, this technique has risen to become the industry standard process for creating reactive metal powders suitable for 3D printing. Learn how plasma atomization works and why you need an oxygen monitor to stay safe with plasma atomization.

How Plasma Atomization Works

Plasma atomization is used not only in 3D printing, but in any circumstance where powder metallurgy is needed. Other uses include spray coating, cold spray, and metal injection molding.

To pulverize metal, wire is fed through a tube, then hit by three plasma torches capable of reaching temperatures of 10,000 degrees Celsius. As the wire liquefies and melts, individual droplets shear off and fall into a chamber filled with argon gas and cooled by water. When the drops of metal hit the argon, they solidify into spherical droplets. This process produces a fine, uniform metal powder. After the wire has been transformed into droplets, the powder is sieved to ensure uniformity. This is key to the success of the 3D printing process, which relies upon fine grade, uniform powder.

Titanium (Ti), Nitinol, Niobium, Aluminum, and other reactive metals and their alloys can all successfully be atomized through this process. Variables in the plasma atomization process allow workers to create droplets of different sizes, for different end uses.

PureAire offers an oxygen analyzer, which many 3D printing manufacturers utilize. This device helps monitor the levels of oxygen in ppm, from 0 to 1000, while the atomization process takes place.

It’s important to keep oxygen levels low while the Ti and other base metals are being turned into powder, as this ensures the purity of the final product. Oxygen analyzers provide a continuous readout of oxygen levels inside the chamber, so your workers can ensure the highest levels of purity at a glance.

Argon gas is used during plasma atomization because it helps ensure the purity of the powdered metal by reducing the chance for chemical reactions that might happen if oxygen interacted with the metal during the atomization. As long as the argon gas remains in the chamber where the aluminum or titanium powder is being made, plasma atomization is quite safe. Like other inert gases, argon depletes oxygen from the atmosphere. Were the argon gas to leak out of the plasma atomization chamber, employees’ wellbeing could be at risk.

Why You Need an Oxygen Monitor with Plasma Atomization

When argon escapes into the environment, it displaces oxygen molecules. Since the gas is both odorless and colorless, there is no way to detect an argon leak by sight or smell. If there are several atomization stations creating Ti or titanium powder at once, the risk increases exponentially.

Once oxygen levels begin to drop, worker safety becomes a concern. If oxygen levels fall below the minimum set by OSHA, workers can suffer respiratory and cognitive impairment. Symptoms include dizziness, confusion, fatigue, and shortness of breath. Even a brief exposure to an oxygen deficient environment can prove deadly.

Fortunately, an oxygen deficiency monitor can continually weigh oxygen present in the room, alerting staff before oxygen levels plunge below the OSHA threshold. This provides sufficient notification via flashing lights and loud alarms for staff to exit the room to safety.

PureAire offers an oxygen monitor with a zirconium sensor. Unlike other sensors, this lasts with no maintenance and no calibration once the O2 monitor is installed. The O2 monitor and oxygen analyzer, when used together, allow for precise manufacturing of powdered metals with low risk to workers. Businesses prefer PureAire products, which are low-maintenance, cost-effective, and reliable for 10+ years. Visit to learn more about our oxygen analyzers and monitors.

Posted in Uncategorized | Tagged , , , , , , , , | Leave a comment

University Environmental Health & Safety Departments: Handling Compressed Nitrogen and Cryogenics


*Oxygen sensor product website

An explosion at a university research lab in Hawaii last year highlights the dangers of working with compressed gas and the need for safety equipment on campus. Learn the dangers of working with compressed gas, how an oxygen deficiency monitor can help, and campus safety best practices.

Compressed Gas on Campus: Uses and Dangers

Compressed gases including nitrogen, argon, and oxygen are widely used on campuses. These gases have many practical and educational uses across educational institutions. While the level of risk varies across schools, a few examples will illustrate the benefits and the risks of using compressed gas on campus.

Argon gas is critical in the 3D printing process, which campus design, fine arts, applied arts, and sciences may use. Culinary programs may use liquid nitrogen for cooking and freezing, and chemistry labs may use N2 as well. Autoclaves, which sterilize equipment, are regularly used in scientific, medical, and industrial programs. Sports programs and physical therapy training programs may use cryotherapy for injury recovery. Cryotherapy chambers rely on nitrogen to chill the air. The chambers can turn deadly if a nitrogen leak occurs. These gases may be used by facilities personnel, researchers, faculty members or teaching assistants and students assisting with teaching labs. No matter which gas students are working with, they are at risk if the gas is not handled, used, stored, or transported properly.

As these few examples illustrate, there are many opportunities for dangerous leaks, explosions, or fires on campus if safety protocol isn’t followed. Many schools find the gases are not properly stored, which leaves everyone on campus in danger. A recent safety bulletin from the University of Rochester found that liquid nitrogen was stored without an oxygen sensor, poisonous gas was used with a fume hood that did not adequately vent hazardous fumes, gas cylinders were modified using unacceptable materials, and gas tanks were stored without protective chains, stands, and gas caps.

Why Schools and Universities Need an O2 Monitor

As the incident in the Hawaiian university lab illustrates clearly, compressed gases pose significant health risks in the university setting. Whenever safety protocol is not followed, the tanks are at greater risk of tipping, falling over, or leaking.

While the lab worker escaped with her life, many others have not been so lucky. A nitrogen (N2) gas leak causes death via asphyxiation in a matter of minutes.

Nitrogen gas is both odorless and colorless. If gas leaks from a canister, there is no way for passerby to tell. As the gas leaks, it lowers ambient oxygen levels below safe thresholds. When levels of oxygen in the air fall below 16 percent, people can experience adverse health affects. Additionally, university property can be damaged by fires or explosions.
All it takes it a couple of breaths of oxygen-deficient air for symptoms including confusion, dizziness, fatigue, muscular aches, lack of consciousness, and even death.

Given the clear dangers that these gases pose, universities and schools must take steps to protect their students and staff. Fortunately, there is an easy and cost-effective way to detect gas leaks and alert everyone before oxygen is depleted from the air: Installing an O2 monitor.

An O2 monitor, also called an O2 deficiency monitor, measures levels of oxygen in the air all the time. As long as the air has adequate oxygen, the monitor will stay silent. When levels fall below safe thresholds, the oxygen deficiency monitor will flash lights and sound an alarm. This way, everyone in the vicinity of the leak can escape without suffering adverse health effects.

An O2 deficiency monitor should be installed anywhere that these gases are used or stored. Universities and schools may wish to equip labs, storage facilities, equipment rooms, and hallways or corridors that connect storage rooms with labs or classrooms where the gas is used.

PureAire offers robust oxygen deficiency monitors that feature best in class construction. Made with zirconium oxide sensors, these monitors offer 10 or more years of maintenance-free performance once installed. These monitors can detect leaks of gases including argon, nitrogen, and helium. View PureAire’s line of oxygen deficiency monitors at

Posted in Uncategorized | Tagged , , , , , , , , , , , , | Leave a comment

Nitrogen Refrigerated Trucks a New Trend? An Alternative to Diesel Powered Refrigeration


nitrogen truck_refrigeration_oxygen_monitorThanks to technological innovations, the food distribution industry has a greener way to protect refrigerated food during transit: Nitrogen refrigeration. The existing system relies on diesel-powdered mechanical refrigeration units. Although these units are effective, they release significant levels of noise and air pollution. While the new innovations decrease emissions to safeguard the environment, there is a hidden health risk transportation companies must take into account.

How Liquid Nitrogen Refrigeration Works

The new system uses a liquid nitrogen system to cryogenically chill food. A storage tank mounted underneath the truck can be easily refilled when empty. Since the tank is stored outside the truck, the liquid nitrogen never comes into direct contact with the food.

To cool the refrigerated container, liquid nitrogen first passes through a heat exchanger. As the nitrogen moves through the heat exchanger, it evaporates. High-powered fans inside the container circulate the chilled air through the compartment, helping keep all food safely chilled below the temperature danger zone.

The traditional mechanical refrigeration system emits significant noise while in operation. Even when the truck itself is off, the refrigeration unit can cause as much as 80 dB of noise, which is roughly as much noise as a busy urban environment. This noise level exceeds the typical noise pollution levels in cities, thus limiting the hours when truckers can make deliveries. Additional downsides to the mechanical refrigeration system include reliance on harmful refrigeration chemicals and expensive maintenance and repair costs.

In contrast, the liquid nitrogen system falls beneath the noise pollution thresholds, so deliveries can be made at any time. This benefits both truckers and restaurants, grocery stores, and other businesses who may want to accept deliveries outside of business hours.

The liquid nitrogen system, or N2 system, also reduces carbon dioxide emissions significantly and does not use harmful refrigerants to keep food cool. Transportation companies who want to green their image or offer their clients increased flexibility will enjoy the liquid nitrogen refrigerant system for these reasons.

While the cryogenic system reduces costs and pollution associated with mechanical refrigeration, the N2 system is not perfect. Liquid nitrogen does pose a safety risk if it comes into contact with the food or the environment. If a truck rollover accident caused a nitrogen spill, for example, individual health and environmental dangers abound.

If the nitrogen gas seeps into the load chamber in the accident, it could turn the truck chamber into an oxygen deficient environment. Staff who opened the truck chamber to check on their load could become dizzy, pass out, and die within minutes of entering the oxygen deficient space.

The liquid nitrogen itself has cryogenic properties, which is why it’s been used to freeze off cancerous cells and warts. A worker cleaning up the spill must take precautions to avoid getting liquid nitrogen on their skin. In a worst-case scenario, an employee could lose a finger if it was immersed in liquid nitrogen.

How to Safeguard Truckers Against Liquid Nitrogen Dangers

An O2 deficiency monitor, also called an oxygen monitor, can protect employees from the dangers posed by liquid nitrogen. These monitors continually measure the amount of oxygen in the load chamber. When the cryogenic system is working properly, oxygen will naturally remain at safe levels and the alarm will stay silent yet vigilant. In the event that nitrogen gas leaks into the load chamber — due to a system malfunction or an accident – oxygen levels will start dropping. Once the environmental oxygen levels falls below OSHA thresholds, the oxygen monitor will flash and sound an alarm. This notifies staff that safety hazards exist, so they will not open the load chamber and enter an oxygen deficient environment.

Since staff can succumb to asphyxiation within minutes, the Odeficiency monitor is necessary to monitor system performance and keep employees safe if anything goes wrong. Since nitrogen is invisible and odorless, employees have no other way to know whether the system’s operating as it should or whether there is an N2 leak.

Oxygen monitors from PureAire use zirconium oxide sensors, which provide reliable service for 10+ years. To learn more about PureAire products, please visit

Posted in Uncategorized | Tagged , , , , , , , | Leave a comment

Neon Gas and Where it is Used. PureAire Oxygen Deficiency Monitors for Safety and Why a Monitor May be Required?


Neon gas has a range of uses in industry, including in the popular business signs advertising stores as open. Explore some of the less well-known ways to use neon and learn how use of the gas may require installation of an oxygen deficiency monitor to protect worker safety.

Uses for Neon Gas

Neon gas can be filtered from helium using activated charcoal in a low temperature environment, or through the selective adsorption method. Once filtered out, neon can be used in the manufacturing of television tubes, plasma screens, and more.

Ne or neon gas is used for advertising signs, as are other noble gases. Neon is also used for television tubes, plasma screens, wave meter tubes, inside lightning arresters, and with high-voltage indicators.

The gas itself has no color until an electric charge is applied that alters the structure of the Ne molecules. Neon gas only produces a reddish orange color light, so other inert gases are used to make other colors. In plasma screens, individual neon lights interact with phosphors within the screen to product the vibrant colors. This interaction allows neon to make other colors.

In its liquid form, neon is extremely cold, and can act as a stronger refrigerant than liquid hydrogen or helium. Thus, the gas can be converted to liquid for use in cryogenic health tanks or other applications. There are potential cryonics applications for neon as well.

In recent years, noble gases including neon have been used to detect fracking leaks. Neon can be tracked as it moved, illustrating the path of leaked methane from the frack site. Neon is a good choice for this purpose since it will not interact with other natural elements.

As one of the inert gases, neon has a low environmental impact. The substance cannot react with other substances in the environment, which could pose harm. Neon is naturally found in the earth’s environment in relatively low concentrations.

Neon gas itself has no color or odor naturally. The noble gas could seep into the environment in a manufacturing leak without anyone knowing what had happened.

How an Oxygen Deficiency Monitor Can Protect Workers From Neon Gas Danger

Like other inert gases, neon can act as an asphyxiant. This means that, if Ne leaks into the air, it begins to displace oxygen in the air. As oxygen levels fall, workers can experience confusion and respiratory problems. If employees do not evacuate in time, they can lose consciousness and die of asphyxiation from the lack of oxygen in the air. In extreme cases, this can happen in a matter of minutes before staff even have time to reach safety.

Since workers cannot see or smell the gas, they need a way to know when they are in danger of asphyxiation. Installing an oxygen monitor is one of these easiest ways to protect employees and provide early warning.

A wall-mounted O2 deficiency monitor continually checks the levels of oxygen in the air, to protect employee health. The monitor stays silent when everything is normal. As soon as oxygen levels fall below the threshold set by OSHA, the monitor will sound an alarm and flash colored lights to provide staff with clear notification. Workers can then evacuate before oxygen levels fall so low that they experience respiratory problems.

PureAire offers an O2 monitor built to withstand 10 years of use with no maintenance once it is installed. Oxygen monitors from PureAire contain zirconium sensors, which are accurate, efficient, and long-lasting. Simply by installing the right O2 monitor, businesses can protect their workers in environments where a noble gas is used.

To learn more about the oxygen monitors PureAire offers, please visit





Posted in Uncategorized | Tagged , , , , , | Leave a comment