What Are Hot Melt Adhesives? Why Are They Used and What Is the Importance Of Nitrogen Gas?

 Hot Melt Adhesives and Available Types Used in Industrial Manufacturing

Industrial hot melt adhesives are polymer-based thermoplastic resins that, when melted, are used to bond materials together. Hot melt adhesives are comprised of one or more base polymers combined with tackifiers (which provide stickiness to the adhesive), plasticizers (to provide greater flexibility), and antioxidants (for protection against degradation) to allow for stability, adhesion, and flexibility.

Industrial hot melt is available in a variety of forms, including granular or powder hot melt blocks, pellets, bags, cakes, drums, and pillows. These materials are solid at room temperature, and then heated, melted, and dispensed for a variety of industrial applications.  As the adhesive returns to room temperature, a strong bond is created, adhering the manufacturing components together.

Hot melt can be dispensed as a liquid or, by introducing an inert gas (such as nitrogen) to the hot melt, as a foam.

Industrial Hot Melt Applications

In either liquid or foam form, hot melt adhesive is used across a wide variety of industries including  aerospace; automotive; product assembly; furniture making, cabinetry, and upholstery; product packaging; book binding; and non-woven sanitary hygiene products.

Aerospace and automobile manufacturers utilize hot melt adhesives for potting electronics (a process used to protect sensitive components from impact or vibration), as well as sealing rivets, seams, and joints. Additionally, hot melt foam is used in airplanes and cars as insulation around doors and windows to reduce vibrations and noise, as well as in seat assembly.

The pages in books and magazines are kept securely bound together using HMAs. The packaging industry depends on a strong adhesive bond to keep the flaps of corrugated boxes and cartons securely closed.

Non-woven personal hygiene products are manufactured by utilizing hot melt adhesives throughout the manufacturing process, including adhering the elastic strands in the leg openings and waistbands, bonding the fabric layers together to secure and stabilize the wetness core, and affixing the fastening tapes to the waistband.

Charring

Charring is akey concern when working with hot melt adhesives, as char (degraded adhesives that have oxidized, hardened into a gel, and been blackened and burned) can negatively affect the adhesives, cause equipment failure, and lead to a shut-down in production.

Key causes of charring include overheating (typically as a result of either using a temperature that is too high for a particular hotmelt, excessive heating times, or incorrect melt tank size); oxidation (exposing the adhesives to too much oxygen), and contamination (from dirt, dust and other materials that fall into the hotmelt and burn).

Once formed, the char can break off into pieces that may clog filters and stop up spray and bead nozzles. The pieces of char can work their way onto the materials to be bonded, leaving marks, streaks, and uneven surfaces. Eventually, bits of char may get into hoses and pumps, breaking seals and scoring and damaging hoses and pump walls.

Why Nitrogen is Used for Hot Melt Adhesive

To reduce potential damage from charring, hotmelt operators may elect to blanket the adhesives with nitrogen (N2) in a process by which nitrogen, an oxygen depleting gas, is piped into the space between the hotmelt adhesive and the top of the hopper or melt tank. The nitrogen blanket protects the adhesive by creating a barrier against falling debris, and it also removes oxygen and moisture which may cause the hotmelt to oxidize and form char .

Oxygen Monitors Improves Quality Control and Helps Protect Employees

To preserve the integrity of the hot melt while blanketing with nitrogen, employees must maintain proper oxygen levels within hoppers or melt tanks, as too much oxygen can cause oxidation. Proper oxygen monitoring equipment should be placed inside melt tanks to measure and control oxygen levels.  A nitrogen leak could lead to failure of the nitrogen blanket, which could compromise the integrity of the adhesives.

Moreover, wherever nitrogen is used, the possibility of nitrogen leaks poses potential risks to humans. Since nitrogen displaces oxygen, a leak could deprive the air of oxygen, thereby creating a possible health hazard for personnel. When there is not enough oxygen in the air, persons working in the area can become disoriented, lose consciousness, or even suffocate due to the lack of oxygen. Since nitrogen lacks color and odor, there is no way, absent appropriate monitoring, for employees to detect a leak.

Best practice calls for oxygen deficiency monitors to be installed anywhere there is a risk of gas leaks. As such, oxygen monitors should be placed wherever nitrogen is stored, and in all areas where nitrogen is used.

PureAire O2 Deficiency Monitors

PureAire Monitoring Systems’ line of Oxygen Deficiency Monitors and Water Resistant Sample Draw Oxygen Monitors continuously track levels of oxygen and will alert hotmelt personnel to nitrogen leaks before employees’ health is put at risk.  In the event of a nitrogen gas leak, and a decrease in oxygen to an unsafe level, the monitor will set off an alarm, complete with horns and flashing lights, alerting employees to evacuate the area.

PureAire’s Water Resistant Sample Draw Oxygen Monitor is a self-contained oxygen deficiency system that is suitable for remote sampling of oxygen levels in confined spaces, hotmelt tanks, and other locations where remote oxygen monitoring is required. The built-in pump samples oxygen levels from up to 100 feet away.

PureAire oxygen monitors measure oxygen 24/7, with no time-consuming maintenance or calibration required. Built with zirconium oxide sensor cells to ensure longevity, PureAire’s O2 monitors can last, trouble-free, for over 10 years under normal operating conditions.Each PureAire O2 monitor has an easy to read screen, which displays current oxygen levels, for at-a-glance readings by hotmelt manufacturers, who derive peace of mind from the monitor’s presence and reliability.

Crispr and the Editing of Genes: To Help Revolutionize Biomedical Science

Scientists from MIT and Harvard University are placing their faith in a gene editing tool that may revolutionize the treatment of deadly diseases. CRISPR, which stands for Clustered Regularly Interspaced Short Palindromic Repeats, has the potential to unlock the next generation of treatments for conditions like cancer, ALS, or Alzheimer's. Learn how CRISPR is poised to change genome editing and biomedicine over the next few decades.

How Does CRISPR Work? 

Bacteria within the body have their own innate intelligence -- the fascination with the microbiome being one example of this scientific principle.

Scientists observed that bacteria was able to fight infections by retaining a slice of DNA from invading viruses, so they could recognize if the virus returned and mount a faster defense. If the intruder returns, the body's natural CRISPR goes after it. Scientists were able to create their own CRISPR, which they can use to edit genes.

You may remember all genes contain chemical basis, referred to by the letters C, G, A, or T. A genetic typo creates markers for disease. Scientists can search for specific bad combinations using CRISPR -- for instance, the gene that would cause ALS -- and then slice out the faulty gene and replace it with something innocuous. By doing this before someone gets sick, the theory goes, CRISPR can save lives. 

Already, scientists are using CRISPR to breed mosquitos that cannot transmit malaria, an application that would save thousands of lives. Others are working to create a stronger rice plant that can withstand floods and drought caused by climate change.

There are a few examples that illustrate the power of CRISPR.

Scientists are still figuring out the true potential of this genome editing tool, however, there is great promise and great enthusiasm for CRISPR's potential from scientists across the globe. In the meantime, laboratory workers must preserve genes and tissue samples for vitality using a nitrogen freezer.

Keeping Tissue Safe in the Laboratory Setting

Nitrogen freezers maintain ultralow temperatures of -150 to -200 Celsius. When genetic material is frozen at such a low temperature, it goes to sleep. The material can be thawed and reanimated for use in the lab setting. Along with low temperatures, the key to maintaining the vitality of the tissue is a slow freeze and thaw. If cells were to freeze too quickly, their cell membranes would burst. The same holds true for thawing frozen tissue. Thus, nitrogen freezers are a mainstay of the lab setting because they provide a reliable, efficient way to keep genomic materials chilled until use.

Any time nitrogen is used, there is a risk of accident if the nitrogen leaks or spills. Nitrogen does not have a color, scent, or odor, which means lab workers wouldn't notice a leak -- although they might notice if, say, the freezer door did not fully close.

Like other inert gases, nitrogen displaces oxygen. If the nitrogen freezer were to leak, the laboratory could lose so much oxygen that workers would experience respiratory distress. To safeguard against a leak, laboratories must use an oxygen deficiency monitor.

An oxygen deficiency monitor tracks the level of oxygen in the lab through constant monitoring. Since nitrogen displaces oxygen, this monitor can detect a gas leak by noting falling levels of oxygen. A digital display indicates the current amount of oxygen in the room, providing assurance for lab staff that everything is working as it should. If oxygen falls to the critical threshold as defined by OSHA, an alarm goes off. Lab workers can exit the premises and wait for emergency personnel to respond.

PureAire creates robust oxygen monitors trusted within the scientific and biomedical communities. PureAire's oxygen deficiency monitors work in freezing temperatures and confined spaces, remain accurate despite barometric pressure shifts, and last 10 or more years without calibration. 

To learn more about PureAire's products, visit www.pureairemonitoring.com

sited sources:

https://www.cbsnews.com/news/crispr-the-gene-editing-tool-revolutionizing-biomedical-research/

https://www.thermofisher.com/us/en/home/references/gibco-cell-culture-basics/cell-culture-protocols/freezing-cells.html

NASA's Uses the Largest Airborne Telescope Observatory in the World

NASA's latest project, a joint collaboration with the German Aerospace Center, breaks new ground for scientific discoveries. The new Stratospheric Observatory for Infrared Astronomy (or SOFIA, as it's known) makes use of a modified Boeing aircraft and a reflecting telescope to enable spatial observations far more detailed than anything a land-based telescope could see. Get a sneak peak inside SOFIA and learn how an O₂ monitor plays a pivotal role in keeping SOFIA safe. 

SOFIA's Mission 

The airplane that powers SOFIA is a short-body 747, which is capable of burning through 3,600 gallons of jet fuel per hour. The plane has been extensively modified to support its new mission, which is to observe the universe using the infrared spectrum of light. This is light that is invisible to the human eye. Interestingly, many objects within space emit only infrared light, meaning that astronomers cannot perceive them with the naked eye. 

SOFIA uses a lot of specialized equipment to make these infrared emissions visible. The telescope on board has a 100-inch diameter. The instrument panel contains cameras, spectrometers, and photometers which operate along near, mid, and far infrared wavelengths to study different scientific phenomena. 

The telescope must be kept clean and properly chilled to see the infrared light. Bathing the telescope in liquid nitrogen keeps it properly chilled, so the telescope can detect midrange and far-out light sources. Nitrogen is used for both of these purposes because it is cost-effective, readily available, and will not damage the sensitive equipment. 

SOFIA will allow astronomers to observe star birth, star death, black holes, and nebulae. It's difficult to forecast what other findings SOFIA may facilitate. 

In some cases, distant objects are blocked by clouds of space dust, much like the sun can become blocked by clouds.  While the space dust prevents these far-off objects from being seem, their infrared energy still reaches SOFIA's powerful telescope. By studying the infrared light captured on SOFIA's instruments, astronomers can learn about new phenomena and come to a better understanding of complex spatial molecules, new solar systems, planets, and more. 

Why SOFIA Needs an Oxygen Deficiency Monitor 

One small but mighty piece of equipment onboard the special aircraft is an oxygen deficiency monitor. SOFIA's powerful telescope must be cooled with liquid nitrogen. The nitrogen storage tank is located inside the crew department. 

Nitrogen gas is heavier than oxygen. In the event of a leak, the nitrogen would actually displace oxygen molecules, causing the cabin air to become deficient of oxygen.

Oxygen-deficient air causes respiratory and cognitive problems within minutes, leading to death via asphyxiation. Since this gas has no color or odor, there is no way the crew can tell there is a leak onboard. This is where the O₂ monitor comes in: By taking continuous readouts of cabin oxygen, the oxygen monitor allows staff to check ambient oxygen levels at a glance. Staff receive peace of mind that everything is operating smoothly as well as a fast alert if oxygen approaches hazardous levels due to a leak of nitrogen gas. 

If a nitrogen leak does occur, the plane must make an emergency landing—aborting the mission to save the life of the personnel onboard. If something goes wrong while SOFIA is in flight, and the aircraft has to land before the mission is complete, the cost of wasted fuel is (pardon the pun) astronomical. 

Since there is so much riding on the oxygen monitor, NASA needed a reliable product, one that would not drift from changes in barometric pressure. While there are many oxygen deficiency monitors, several products on the market are sensitive to barometric pressure shifts. PureAire offers hardy O₂ monitors that are capable of maintaining reliable performance despite barometric changes. 

Our O₂ monitor lasts for 10 or more years after installation with no maintenance required, thanks to a robust zirconium sensor that outperforms the competition. After installation, our oxygen deficiency monitor needs no calibration to continue working accurately. If there is a nitrogen leak, the oxygen deficiency monitor provides two built-in alarms, which operate at 90 decibels. These alarms—which correlate to 19.5 percent and 18.0 percent oxygen—provide the SOFIA crew with sufficient notification of any problems, so they can return to safety. 

It's thrilling to have our products be a part of such a vital mission, and we cannot wait to see what new discoveries SOFIA facilitates. Closer to home, PureAire supports clients in a range of industries with high-value, long-lasting oxygen monitors suitable for use anywhere they are needed. Learn more about PureAire's products at pureairemonitoring.com.

Source

https://space.stackexchange.com/questions/12295/why-do-some-space-telescopes-require-cooling-sometimes-down-to-3k

Aluminum Extrusion: Staying Cool with Nitrogen

Aluminum is a highly malleable material, which is readily shaped for any number of purposes. The aluminum extrusion process is key to shaping aluminum, and it must be completed in an inert environment to reduce the formation of oxides. Learn why this is important and how facilities can reduce the risks of health hazards in an inert environment. 

How Aluminum Extrusion Works

Billets of aluminum are first heated to above 800 degrees Fahrenheit to become malleable, then coated with a lubricant so the molten metal will not stick to the extruding ram. 

The ram presses the aluminum billet through a die, which is cast in a given shape. As the aluminum passes through the die, liquid nitrogen flows over the metal to prevent oxides from adhering to the aluminum. This also extends the lifespan of the die by cooling it. In some operations, nitrogen gas is used instead of liquid. While the overall purpose is the same -- to keep out oxides, which can cause the extruded aluminum to crack -- the gas does not cool the die. 

The shaped aluminum passes through the die, then exits the press where its temperature is taken. Temperature records help maintain press speeds, for plant efficiency. The extruded aluminum pieces are then transferred to a leadout table and a puller, where the metal is cooled using fans. Some mixtures of aluminum are cooled with water as well as air. 

The cooled and cut aluminum is then stretched via a stretcher, a step that increases the hardness and strength of the finished piece. Finally, extruded aluminum pieces are cut for precision and aged under controlled temperatures via heat treatment. 

The entire process resembles a play-doh modeling kit, where the dough is squeezed through a press and comes out in a tube or a star shape, for instance. 

Extruded aluminum pieces are used in a variety of industries, including railway cars, lightweight automobiles, bridge decking, solar panels, and coaxial cables. 

Whether liquid or gaseous nitrogen is used, there is a risk of a nitrogen leak causing an oxygen deficient atmosphere. Nitrogen is naturally heavier than oxygen, so it displaces the oxygen molecules in the atmosphere. Since nitrogen has no color, odor, or scent, employees are unable to tell there's a leak. A leak poses health hazards in addition to work disruption and revenue losses. Fortunately, there's an easy way to protect facility staff. 

Why Oxygen Sensors Should Be Used With Aluminum Extrusion 

When nitrogen displaces oxygen, oxygen levels start to fall unbeknownst to anyone present. Eventually, oxygen levels will grow dangerously low. In an oxygen deficient environment, employees may start to feel dizzy or confused. Some may sweat, start to cough, or experience rapid breathing and increased heart rate. Death via asphyxiation is a real risk. 

An oxygen sensor provides assurance that there is no leak, since it tracks levels of oxygen in the room 24/7. As long as oxygen levels are above the OSHA threshold of 19.5, the monitor will be silent. If liquid or gas nitrogen starts to leak, leading oxygen levels to fall, the monitor will sound an air horn and flash lights. Staff will understand there is a problem and will have time to evacuate to safety. Staff can also check the monitor face at any time to see oxygen levels at a glance. 

PureAire offers oxygen monitors that feature zirconium sensors, which last long and withstand shifts in barometric pressure and temperature. These monitors can operate for over 10 years with no annual maintenance or calibration. PureAire's monitors work in temperatures from -40 Celsius to 55 Celsius and even function in confined spaces, such as basements or freezers.  Learn more about PureAire's products at www.pureairemonitoring.com. 

Taste the Difference with Nitrogen Packed Coffee Grounds

When it comes to flavor, coffee purists prefer whole beans, which retain their flavors longer than ground coffee. Yet there's no denying the convenience factor of ground coffee, which is why it's so popular in offices. Ground coffee has a short shelf life -- hence the push to use airtight containers, which keep the flavors in the coffee -- and off flavors may develop if the coffee grounds are left on the shelf too long. Some coffee companies are trying a new trick to add shelf stability to their ground coffee: a nitrogen flush.

How Nitrogen Flushing Preserves Coffee Grounds

Oxygen is the enemy of ground coffee: When coffee grounds come into contact with oxygen, they go stale faster. This is why coffee grounds are sold in vacuum-sealed containers, and why consumers are encouraged to use airtight containers. For best flavor, coffee beans should also be stored in dark containers (so light does not pass through).

Some amount of oxygen is produced (in the form of CO₂) as the ground coffee degasses, a naturally occurring process. To release these gases and preserve coffee flavor, many coffee bags contain a one-way valve. Oxygen escapes through the valve, but cannot come back into the bag.

Some coffee companies are taking it one step further by flushing the bag with nitrogen gas during the coffee packaging process, which ensures that no oxygen is in the bag with the coffee where it would cause spoilage. Nitrogen gas is heavier than oxygen, so when it is pushed into the empty coffee bag, it displaces oxygen. The bag is then filled with coffee grounds and sealed with no ambient oxygen in the sack. This preserves coffee flavor.

Since nitrogen gas has no color or odor, it does not affect the taste of the coffee. What consumers get, months later, is grounds that are as fresh as they were the day the coffee was roasted and ground.

While this is beneficial for the consumer, nitrogen flushing may prevent problems at the packaging plant. Just as nitrogen gas flushes oxygen out of the bag, so can it displace oxygen from the room. If a leak were to occur, employees would not be able to tell (remember, the gas has no smell, odor, or color). A leak could push so much oxygen out of the air that staff could suffer respiratory problems, death via asphyxiation being the worst-case scenario.

How an Oxygen Sensor Can Protect Your Employees

Since nitrogen displaces oxygen, it's easy to detect a leak by tracking the levels of oxygen in the room. Oxygen sensors -- also known as oxygen deficiency monitors -- continually monitor oxygen levels. As long as the room air remains stable, there's no leak. When the levels of oxygen in the air fall to the OSHA threshold of 19.5 percent, where a health threat is imminent, the sensor will go off. Employees will see a flashing light and hear a loud alarm that warns of the low levels of oxygen. Staff can exit the packaging facility without suffering adverse health effects; they also enjoy peace of mind every day by checking the O₂ monitor.

PureAire supplies coffee manufacturers with oxygen sensors that help them offer a higher-quality product without placing workers at risk. PureAire's oxygen deficiency monitor requires no maintenance and calibration once installed, thanks to a hardy zirconium sensor. Once installed, the O₂ monitor will provide accurate readouts and leak detection for 10 or more years. PureAire's oxygen deficiency monitors function properly despite changes to barometric pressure, thunderstorms, and other weather events. Suitable for use in freezers, basements, and other confined spaces, PureAire's monitors perform in temperatures from 55 Celsius to -40 Celsius.

To protect worker safety, an oxygen monitor should be used wherever nitrogen gas is stored or used. Learn more about PureAire's products at www.pureairemonitoring.com.

Gas Chromatography and Breathe Safely While Using Nitrogen

Gas chromatography is a process used to separate chemical compounds for analysis. The analytical chemistry process is used with gases that won't decompose when vaporized. Gas chromatography are used in a wide range of industries -- everything from forensic science to medical marijuana. While the procedure is highly useful, there are risks when working with nitrogen gas. Learn how gas chromatography works, the role nitrogen plays, and how an oxygen sensor improves safety. 

How Gas Chromatography Work

In chromatography, one gas moves over the sample substance. The moving gas is known as the mobile phase, and it's usually an inert gas, such as nitrogen or helium. As the mobile phase passes over the substance, it separates out into its component parts. Since accuracy is key, it's vital that the moving gas not react with the substance being analyzed. For this reason, inert gases are recommended for gas chromatography.

Gas chromatography takes place within a special machine, known as a gas chromatograph machine. The substance being studied is injected into the chromatograph with a syringe, then the material is heated to the vapor stage. The carrier gas -- e.g. nitrogen -- is then added to the chromatograph to push the sample up the central column. As the substance being analyzed passes up the column, it's absorbed by the carrier and then separated into its distinct components. The components emerge from the column and pass through a detector, where they are identified and noted on a chart.

When the process is complete, every part of the mixture is identified. At this point, for instance, a forensic scientist will have the raw data needed to analyze evidence found at the crime scene. While television shows may portray the process as instant, it's often time-consuming.

Within the medical marijuana industry, scientists are using gas chromatography to test for pesticide residue in cannabis. While the medical marijuana industry is still young, and pesticide levels are not heavily regulated, industry leaders expect this to change as the marijuana industry grows. Thus, the use of gas chromatography to check for pesticides will grow too.

Whenever gases is used in the chromatography process, there's a potential for gas leaks, whether from the supply lines, storage tanks, or from the chromatograph itself. Nitrogen gas displaces oxygen. If nitrogen were to leak, air levels would become deficient of oxygen and employees could suffer health problems. 

Since nitrogen gas has no color or odor, there is no way for lab staff to tell that the gas has leaked. The best way to safeguard the lab is with an oxygen monitor. 

How an Oxygen Deficiency Monitor Protects Employees 

Risks of breathing oxygen deficient air include dizziness, fatigue, unconsciousness, and death via asphyxiation. All it takes is a couple breaths of air to experience adverse health effects. 

Since there is no way to tell whether a leak has occurred, it's necessary to use an oxygen sensor to track oxygen levels at all times. The oxygen monitor or sensor measures oxygen and only reacts when levels fall below a predefined threshold. Oxygen sensors from PureAire have alarms for oxygen levels of 18 percent and 19.5 percent, for instance. 

The oxygen deficiency monitor includes a flashing light and loud alarm, so that staff and passerby receive prompt notification of the leak. When the alarm goes off, employees can vacate the premises and contact emergency personnel. 

Given the serious risks posed by a nitrogen gas leak, it's important to use oxygen deficiency monitors anywhere inert gases are stored or used. 

PureAire is an industry leader when it comes to oxygen monitors. O₂ monitors from PureAire are designed for long-lasting and maintenance-free use. They feature a zirconium sensor, which lasts for 10-plus years without calibration. PureAire's monitors can handle temperature changes, barometric shifts, and even freezing temperatures. Learn more about PureAire's monitors and how they promote safety at 

www.pureairemonitoring.com.

Source: http://www.explainthatstuff.com/chromatography.html

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

*Click here for oxygen monitor details

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 www.pureairemonitoring.com.
 

http://cen.acs.org/articles/94/web/2016/04/Spark-pressure-gauge-caused-University.html

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

Nitrogen Truck Refrigeration

Thanks 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 O₂ deficiency 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 www.Pureairemonitoring.com.

http://www.bbc.com/news/magazine-19870668

Nitrogen Demand Increases for Semiconductor: How Safe Are You?

As users demand ever-smaller smartphones and better televisions, semiconductor manufacturing plants are tasked with developing new products faster and using new materials. Key to the continued success of the semiconductor industry are inert gases, which include nitrogen and argon. When used safely, both nitrogen and argon play a number of important roles within the semiconductor plant. Yet, these gases poses a health hazard for employees if a leak occurs. 

How and Why Nitrogen is used in Semiconductor Manufacturing Plants 

Nitrogen is used throughout the manufacturing process, from purging pumps to abatement. Nitrogen is also used in the process, especially now that fab size is growing. In a modern semiconductor manufacturing plant, as much as 50,000 cubic meters of nitrogen gas are used every hour. 

To meet this demand, semiconductor manufacturing plants are installing nitrogen generators onsite. Generators mean a cheap, efficient, and always-ready supply of nitrogen gas to supply production. 

As long as nitrogen gas is stored safely in the generator and used properly, there is no health risk. Yet if the generator or supply lines develop a leak, nitrogen gas can escape and deplete oxygen in the environment. Since nitrogen gas is both odorless and colorless, there is no way that staff can monitor their risk. 

Along with nitrogen, argon gas is used in semiconductor manufacturing, most notable as a sputtering gas. Like nitrogen, argon gas depletes oxygen from the environment. Like nitrogen, the gas has no color or odor. In a closed area, the gas can deplete oxygen and cause respiratory problems and eventual suffocation. 

How an Oxygen Analyzer Can Protect Staff Working in a Semiconductor Manufacturing Plant 

If either nitrogen or argon were to leak into the plant, these inert gases would begin to deplete the levels of oxygen in the air. OSHA sets the oxygen threshold at 19.5 percent or less oxygen in the air. If oxygen levels fall below this, staff could suffer. 

When oxygen levels fall to OSHA's threshold, staff may show signs of confusion or fatigue. Since there are no warning signs that something is wrong, staff can fall unconscious before they can escape the oxygen deficient environment. Once unconscious, they asphyxiate. 

It is critical for any workplace that uses these inert gases, including semiconductor plants, to monitor levels of oxygen in the air and alert workers if the ambient oxygen levels fall to the OSHA threshold. 

By installing an oxygen monitor and an oxygen analyzer anywhere inert gases are used, manufacturers can protect the safety of their workers through continual oxygen monitoring and fast alert if oxygen levels fall. A wall-mounted oxygen monitor scans the atmosphere and measures the amount of oxygen from 0 to 25 percent, well above the safety threshold. As long as there is enough oxygen in the air -- which there will be as long as there is no inert gas leak -- the oxygen monitor will remain silent. 

When oxygen levels fall to the OSHA threshold, the oxygen monitor will flash lights and sound an alarm, providing instant notification to workers. Staff can take notice and evacuate before negative health outcomes occur. 

An oxygen analyzer measures the level of oxygen present in gas produced via nitrogen generator to ensure the purity of the gas for use in manufacturing. Oxygen analyzers are ideal for low level analysis and can measure from 0 to 1,000 ppm. Workers can check oxygen levels at a glance and ensure the nitrogen generator is working properly. When combined with the oxygen monitor for safety, the oxygen analyzer streamlines and safeguards the semiconductor manufacturing process. 

PureAire offers industry leading oxygen monitors and oxygen analyzers that can last for up to 10 years after installation with no maintenance needed. These products offer worker protection and peace of mind for manufacturers who want to remain cutting edge in their industry. Learn more about PureAire's products at https://www.pureairemonitoring.com.

Tunnel Freezing and Flash Freezing Food with Nitrogen: Oxygen Monitors and Why They May Required

New developments in cryogenic freezing are transforming the frozen food industry by making it easier to freeze all sorts of items quickly while retaining the highest nutritional value. Cryogenic and tunnel freezers are easy to use, yet they pose a hidden health risk. Learn why you may need an O2 monitor if your frozen food manufacturing facility relies on cryogenic freezers.

                                                              

How Cryogenic Freezers Work

Cryogenic freezers allow for continuous freezing of food, increasing output without requiring a large amount of space. Compared to mechanical freezers, which take longer to freeze products, they increase both the production and the quality with a low investment of capital.

In particular, cryogenic freezers are useful for freezing par-baked goods, which are partially baked before being frozen for storage. Par-baked items allow fast-food restaurants, supermarkets, sandwich shops, cafes, and other institutions to offer fresh, healthy baked goods without needing to bake from-scratch every day. For a commercial baking facility, investing in a cryogenic freezer is the best way to increase their output, grow their business, and become more profitable.

Cryogenic freezers work by using liquid nitrogen to quickly chill items to safe temperatures for frozen storage. As in any environment where liquid nitrogen is present, there is a danger of oxygen depletion and asphyxiation. Thus, it is always a good idea to have an O2 deficiency monitor present onsite to protect the health of employees.

One subset of cryogenic freezers, the tunnel freezer, uses a continuous freezing model of a conveyor belt, an injection system, and an exhaust system to vent gases. When the texture of the finished product is paramount, as in baked goods or seafoods, or when it's necessary to flash freeze hot foods quickly, a tunnel freezer is the best way to maintain quality in the end product.

Why an Oxygen Detector is Necessary with Cryogenic Freezers

As mentioned above, cryogenic tunnel freezers rely on an inert gas, nitrogen, to flash freeze food items. Nitrogen is perfectly safe when used in the closed-loop freezer system and properly vented from the facility. However, if the exhaust system were to develop a leak, nitrogen gas could enter the manufacturing facility and start to displace oxygen from the air. Since nitrogen is colorless and odorless, staff would not notice the leak. In a matter of minutes, ambient levels of oxygen could drop so severely that staff could become disoriented, lose consciousness, or die.

Simply by installing O2 monitors wherever nitrogen gas is used or stored, you can monitor levels of oxygen in the air and ensure there is no risk of oxygen displacement from a nitrogen leak. In the event that nitrogen leaks into the environment, the O2 deficiency monitor will sound an alarm and flash lights to let staff know that oxygen levels have fallen below the acceptable threshold set by OSHA. Staff can then evacuate before their health is compromised.

There are many styles of O2 monitors, but the one we recommend for flash freezing environments is the Sample Draw oxygen monitor. The style of O2 monitor can be placed outside the freezer and monitor levels of oxygen inside the freezer using a polyurethane tube. This ensures the sterility of the flash freezing environment while safeguarding workers. With a state-of-the-art zirconium oxide sensor, this style of oxygen detector can last without any maintenance for up to 10 years.

PureAire has over 15 years of experience, and is an industry leader in oxygen detector technology. To learn more about the Sample Draw oxygen monitor, please visit www.PureAireMonitoring.com.

A Nitrogen Culinary Experience and How to Remain Safe with Use of Oxygen Monitors

As modernist cuisine has become more popular, restaurant and home chefs alike are turning to liquid nitrogen to create spheres, gels, foams, and even ice cream. While liquid nitrogen can be safely used in a range of culinary applications, there are important safety risks to be aware of when working with this substance. 

The Hidden Dangers of Liquid Nitrogen in the Kitchen

Nitrogen can help chefs freeze alcohol, which doesn't freeze under freezer temperatures. Nitrogen also creates a very rich ice cream, since it makes superfine ice crystals. By using liquid nitrogen to freeze foods, chefs can keep more flavor in the food and preserve higher amounts of the food's nutrients.

It's important to note that nitrogen is used only to alter the state of food. The nitrogen itself is not consumed.
While it is no wonder that nitrogen has become so popular in the kitchen, the substance can pose a health hazard.  

Liquid nitrogen is extremely cold. If the substance were to spill on your clothing or get in your eyes, it could cause severe burns. Thus, many culinary workers wear an extra layer of clothing (such as an apron) to prevent nitrogen from causing skin burns. Special gloves protect the hands, and safety goggles prevent the eyes from nitrogen burns.

While many are aware of the burn danger from liquid nitrogen, there is a more insidious hazard. When liquid nitrogen meets the air, it starts to evaporate and turns into nitrogen gas. Nitrogen gas is a known oxygen displacer, so the more gas that escapes, the less oxygen the air has. Quickly, nitrogen gas can deplete the air to low enough levels of oxygen that respiratory problems and death via asphyxiation are cause for concern. While you may see the smoke or fog from liquid nitrogen, actual nitrogen gas has no color or odor. Thus, if you miss the fog of liquid nitrogen, you may not know the atmosphere is oxygen deficient until it is too late. 

The human brain requires a continual supply of oxygen to work properly. Without this steady oxygen supply, the brain begins to shut down. Confusion and mental fog occur, along with symptoms of respiratory distress, including nausea and vomiting. Due to the severity of these symptoms, an individual in an oxygen-deficient environment has little chance of rescuing themselves before dying. 

How an Oxygen Monitor Protects Safety 

If you plan to use liquid nitrogen, take the necessary precautions to protect skin and eyes from burns. Then take the extra step to install an oxygen deficiency monitor or oxygen analyzer. 

The oxygen deficiency monitor mounts on the wall in the area where nitrogen is stored and used. The device constantly checks the levels of oxygen in the air. As long as the air is safe to breathe, the monitor remains silent yet alert. If liquid nitrogen evaporates and begins displacing oxygen, the O₂ monitor tracks the falling levels. Should oxygen drop such that the air is no longer safe to breathe, the O₂ monitor will flash a visual and audio alert telling staff to get out of the kitchen. 

The monitors are designed to alert when oxygen levels fall below the limits set by OSHA of 19.5 percent. When oxygen levels are between 19.5 and 15 percent, symptoms of oxygen deficiency begin to occur. Health hazards arise when levels fall below 6 percent. So, the analyzer gives staff enough time to safely evacuate and avoid a health risk. 

If you want to use nitrogen in the kitchen, while reducing the safety risks for your kitchen staff, invest in an oxygen monitor. Oxygen monitors from PureAire come with hardy zirconium oxide sensors, which require no maintenance and have a 10-year life span. They are an effective, efficient way to circumvent nitrogen's hidden dangers. See PureAire's line of oxygen monitors and oxygen analyzers at www.pureairemonitoring.com