Monday, November 8, 2021

Protecting Against Oxygen Deficiency Risk

 

What is Oxygen Deficiency?

The air we breathe is made up of 78% nitrogen, 21% oxygen, and trace amounts of other gases such as carbon dioxide, neon, and hydrogen. The Occupational Safety and Health Administration (OSHA) defines an environment in which oxygen levels fall below 19.5% as an oxygen-deficient atmosphere, which should be treated as immediately dangerous to health or life.

How is Oxygen Deficiency Dangerous?

Oxygen deficiency is often called a silent killer, because there are no warning signs when oxygen concentrations drop to an unsafe level.

Inhaling just a few breaths of oxygen-deficient air can have immediate negative effects, which may include impaired coordination, accelerated respiration, elevated heart rate, nausea, vomiting, loss of consciousness, convulsions, or even suffocation due to a lack of sufficient oxygen.

Where can Oxygen Deficiency Occur?

Oxygen deficiency can occur in any location where compressed oxygen-depleting gases are used, stored, or may accumulate.

Industries that commonly use these types of gases include, but are not limited to, laboratories, MRI, food and beverage, cryogenic facilities, aerospace, pharmaceutical, research and development, alternative fuel, waste management, semiconductor, additive manufacturing, and the oil and gas sectors.

Manufacturers and other organizations utilizing compressed, oxygen-depleting gases in their operations need to successfully navigate complex working environments in which high concentrations of such gases may be critical to production procedures, but where the risks of oxygen deficiency may pose a potential safety hazard for their employees.

Fortunately, by utilizing a top-quality oxygen deficiency monitor, facility managers can maintain stringent processing requirements, as well as protect the health and safety of their personnel.

What is an Oxygen Deficiency Monitor?


An oxygen deficiency monitor is a device that measures oxygen levels in a particular area. By continuously tracking oxygen levels, oxygen deficiency monitors are designed to detect oxygen-depleting gas leaks before employee health is jeopardized.

A number of oxygen-depleting gases, including nitrogen, helium, carbon dioxide, and argon, among others, are both odorless and colorless. As such, unless they are using a reliable oxygen deficiency monitor, personnel working with such gases would likely be unable to detect a gas leak should one occur in a gas cylinder or line, and they could likewise be unaware that they were breathing oxygen-deficient air.

PureAire Oxygen Deficiency Monitors

    


PureAire Monitoring Systems’ line of Oxygen Deficiency Monitors offers thorough air monitoring, with no time-consuming maintenance or calibration required. An easy-to-read screen displays current oxygen levels for at-a-glance reading by employees, who derive peace of mind from the Monitor’s presence and reliable performance.

Our Monitor continuously tracks oxygen levels and, in the event of a gas leak and a drop in oxygen to an OSHA action level, will set off an alarm, complete with horns and flashing lights, alerting employees to evacuate the affected area.

The Monitor will remain accurate at temperatures as low as -40C. PureAire's durable, non-depleting, long-life zirconium oxide sensor will last for 10+ years in a normal environment without needing to be replaced.

To reduce risk to personnel, PureAire's optional Remote Digital Display may be placed well outside of high risk rooms (up to 250 feet from the Monitor itself), where it will safely exhibit oxygen levels inside the room.



Thursday, August 19, 2021

Carbon Dioxide Safety – Why It’s Important to Monitor Carbon Dioxide

 


What is Carbon Dioxide?

Carbon dioxide is the fourth most abundant gas in the earth's atmosphere after nitrogen, oxygen, and argon. At room temperature, carbon dioxide (CO2) is a colorless, odorless, non-flammable gas, but at different temperatures and pressures, carbon dioxide can be a liquid or a solid (i.e., dry ice).

Carbon dioxide is produced when fossil fuels are burned, or as vegetation decays. CO2is also generated as a by-product in certain manufacturing processes, such as during the fermentation stages when making beer and wine.All living beings exhale carbon dioxide as a normal part of the respiration process, and plants require carbon dioxide for photosynthesis to take place.

Carbon dioxide displaces or depletes oxygen and, at unsafe levels, can cause dizziness, confusion, headache, shortness of breath, unconsciousness, and even death due to asphyxiation. Carbon dioxide may accumulate in confined spaces, causing health and safety hazards.

What is a Carbon Dioxide Monitor?

A carbon dioxide monitor is used to track carbon dioxide levels in targeted areas.Monitors are used to verify that carbon dioxide levels are within a range sufficient to ensure the safety of occupants within the tested areas.  CO2 monitors are programmed to alert personnel when CO2 levels reach an unsafe threshold.

Additionally, CO2 monitors may be used in greenhouses or grows rooms to ensure that appropriate concentrations of carbon dioxide are maintained to yield healthy crops. Increased carbon dioxide levels stimulate the photosynthesis process, resulting in stronger and faster-growing plants, but the levels must be monitored closely, as too much CO2 can damage plants, as well as present health risks to employees.

The Occupational Safety and Health Administration (OSHA) has established a permissible exposure limit (PEL) for carbon dioxide of 5,000 parts per million (ppm) averaged over an 8-hour workday (time-weighted average or TWA).

The National Fire Protection Association (NFPA) code 13.7.2 stipulates that rooms or areas where CO2 container systems are filled and used indoors or in enclosed outdoor locations shall be provided with a gas detection and alarm system capable of detecting and notifying the building occupants of a gas release or carbon dioxide levels above the OSHA PEL of 5,000 ppm. Additionally, NFPA specifies that the gas detection system must be capable of initiating an audible alarm within the room or area in which the system is installed.

Industry Applications

Carbon dioxide monitors are designed for use in a wide range of applications, such as the food and beverage industry (breweries, wineries, bottling plants, bars and restaurants, food processing, and frozen food production facilities), laboratories, universities, pharmaceutical manufacturing, agricultural locations, schools, and office buildings.

Bars, restaurants, and fast-food establishments all rely on CO2 to carbonate beverages such as soda and beer and, as such, all require the use of CO2 monitors.

Pharmaceutical manufacturers use carbon dioxide to purge oxygen from packaging, not only to maintain a sterile environment but also to protect products during transport, and to prolong the stability and shelf life of the packaged drugs.Additionally, dry ice (the frozen form of carbon dioxide), is used to keep temperature-sensitive medicines at required cold temperatures.

A diverse array of indoor gathering places, including office buildings, schools, and retail locations, monitor carbon dioxide levels to measure indoor air quality and ensure that safe oxygen levels are maintained. Building HVAC systems may be programmed to activate their ventilation systems to recirculate and refresh the air in response to elevated CO2 levels.

PureAire Carbon Dioxide Monitors

PureAire’s Carbon Dioxide Monitor offers thorough air monitoring, with no time consuming maintenance or calibration required. Air quality measurements are taken every 2 seconds and are visible on the Monitor’s easy-to read backlit display. In the event of a rise in carbon dioxide levels to an OSHA action level, the Monitor will set off an alarm, complete with horns and flashing lights, alerting personnel to evacuate the affected area.

In certain applications, including inside greenhouses and grow rooms, the carbon dioxide alarm can be set to maintain desired CO2 levels, and can be programmed to go off when CO2 levels change.

PureAire’s Monitor can be linked to a Programmable Logic Controller (PLC), a multi-channel controller, a remote display, or tied into building HVAC systems themselves.

Our Carbon Dioxide Monitor includes an NDIR sensor cell to reliably measure CO2 levels. The monitor will remain accurate over a wide range of temperatures (0-50°Celsius) and humidity levels (0-95%RH), as well as changes in barometric pressure.

Where Should Carbon Dioxide Monitors Be Installed?

The specific application will determine where best to install a PureAire CO2 Monitor. For example, bars and restaurants serving carbonated beverages should install a Monitor 12-18 inches off the floor in areas where compressed CO2 is stored or used.

For applications that require high concentrations of carbon dioxide, such as inside greenhouses and grow rooms, the Monitor may be mounted inside the room, with employees utilizing a remote display located on the outside for at-a-glance visibility.

To ensure safety, PureAire generally recommends that one monitor be installed for approximately every 400 square feet of your facility’s space. However, since airflow can be unpredictable, we encourage you to contact PureAire for additional guidance specific to your needs.

Saturday, June 26, 2021

The Hidden Dangers Inside Boiler Rooms - Why You Need a Boiler Room Gas Monitor

 


In an effort to prevent boiler room accidents due to elevated levels of carbon monoxide, the Texas Department of Licensing and Regulation (TDLR) has adopted new regulations (16 Tex. Admin. Code § 65.206) regarding carbon monoxide (CO) gas detection equipment that is used in boiler rooms built on or after September 1, 2020.

Carbon monoxide

Carbon monoxide gas is produced from the incomplete burning of natural gas, wood, coal, oil, propane gas, or anything else that contains carbon. In enclosed spaces such as boiler rooms, where fuels such as natural gas, oil, coal, or propane may be used,  CO levels can rise quickly creating a dangerous health and safety risk. Carbon monoxide is an odorless, colorless, tasteless, and flammable gas that can be deadly within minutes without warning.

Exposure to CO can cause chest tightness, headache, fatigue, dizziness, nausea, confusion, loss of consciousness, and even death.

Additionally, carbon monoxide gas is highly flammable and can ignite easily when exposed to oxygen and/or source of ignition such as a spark or excessive heat.

Methane

Methane (CH4), a primary component of natural gas, produces carbon monoxide if incompletely burned. Methane, like CO, is colorless, highly flammable, and odorless unless an additive is used to give it an odor . High levels of methane can deplete oxygen causing headaches, dizziness, weakness, loss of coordination, and asphyxiation.

Keeping Boiler Rooms Safe with a Dual CO/CH4 Combustible Gas Detector

Carbon monoxide is often referred to as a silent killer because it has no warning properties. Absent appropriate gas detection equipment, people working in and around boiler rooms, would be unable to detect an accumulation of carbon monoxide.To detect, and protect against, risks emanating from excessive concentrations of CO or CH4, best practices include placing gas detection monitors, containing visual and audible alarms, in boiler rooms where carbon monoxide or methane may accumulate.

PureAire Gas Detectors

PureAire Monitoring Systems’ Dual Carbon Monoxide/Methane Combustible Gas Detector offers continuous readings of CO and CH4. The gas detector features an easy to read screen, which displays current carbon monoxide and methane levels for at-a-glance observation by employees servicing boiler rooms, who derive peace of mind from the detector’s presence and reliable performance. In the event of an accumulation of carbon monoxide or methane to an unsafe level, the detector will set off an alarm, complete with horns and flashing lights, alerting personnel to evacuate the area. At the same time, the PureAire gas detector can be programmed to disable the burners when CO levels reach a user selectable ppm level.

The monitor is housed in a NEMA 7 explosion proof enclosure suitable for Class 1, Division 1 and  2, Group B, C,  and D.


Wednesday, May 5, 2021

Solvent Safety in Pharmaceutical Manufacturing

 


The manufacture of pharmaceutical products is a complex and multi-stage operation that can include processes such as blending, wet and dry granulation, milling, hot-melt extrusion, coating, andtablet pressing. Producing the exact formulation, release rate, consistency, and dosage form requires many chemical compounds and substances.

Among the mare active pharmaceutical ingredients (API), the primary and biologically active medicinal component of the drug; excipients, the non-active components, including lipids,which serve as carriers, solubilizers, or emulsifiers of the active ingredients; and plastics or polymers used in production to create the dispensing form of the finished pharmaceutical product.

Lipids and Polymers

Lipids and polymers are vitally important to the drug production process. They are used for the fabrication of most dosage forms, release rate modifiers, enhanced drug absorption, stabilizers, solubilizers, and more.

Lipids, which are soluble in organic solvents such as ethanol, isopropyl alcohol, acetone, and benzene, are purified and refined to be used as fillers, binders, lubricants, solubilizers, emulsifiers, and emollients in a variety of delivery forms, including tablets, capsules, suppositories, emulsions, ointments, creams, and lotions.

Polymers are used in a wide variety of applications that can include everything from film coatings on medicines, to controlling the release rate of drug formulations.They are also used as a taste masking agent, stabilizer, thickener,and as a protective agent in oral drug delivery.

Solvents such as acetate, methanol, isopropanol, and ethyl acetate are used dissolve or disperse the polymer materials and apply them to the surface of the tablets and capsules.

Solvents

Solvents can be solid, liquid,or gas and are often used to dissolve, disperse, suspend, or extract other materials during pharmaceutical manufacturing. They can also be used as the medium in which the chemical reaction takes place to make APIs. To maintain a sterile environment and adhere to strict quality control standards, solvents such as isopropyl alcohol may be used to clean and disinfect surface areas and equipment.

Depending upon the manufacturing stage, the solvent being used can be either organic ( i.e., carbon-based), such as hexane, alcohols (including isopropyl, ethanol, and methanol), toluene, and acetone, among others; or inorganic solvents ( i.e., non-carbon-based), including water (the simplest and most abundant), ammonia, hydrogen fluoride, and sulfur dioxide.

Potential Safety Risks Involved with Solvent Use

While solvents are necessary components of the medicine formulation process, exposure to solvents is one of the most common hazards in the pharmaceutical production industry. Solvents can irritate the eyes and respiratory tract, cause damage to the liver, kidneys, heart, blood vessels, bone marrow, and the nervous system. Inhalation of some solvents may have a narcotic effect, causing fatigue, dizziness, unconsciousness, and even death.

Moreover, many of the organic solvents used in pharmaceutical manufacturing, such as hexane, acetone, methanol, isopropyl alcohol, ethanol, and toluene,are highly volatile, as well as flammable or combustible.

Combustible Gas Monitors Can Reduce Risk in Pharmaceutical Facilities Utilizing Solvents

Solvent vapors are very often flammable and, depending on the solvent, even explosive. It is critically important to understand the lower explosive limits (LEL) of the solvents being used, because LEL reflects the lowest concentration of gases or vapors in the air that could cause combustion in the presence of an ignition source, such as static electricity , heat, or flame.

Best practices call for combustible gas detectors to be installed in any area where flammable or combustible solvents are used or stored. In the event of a leak, and an accumulation of solvent vapors, an LEL gas detection monitor should activate visual and audible alarms, and turn on the ventilation system.

PureAire Monitors

PureAire Monitoring Systems’ line of LEL Combustible Gas Monitors is designed to meet the safety needs of pharmaceutical manufactures utilizing solvents. The Monitor is housed in a NEMA 4 explosion-proof enclosure suitable for Class 1, Groups B, C, and D, and Class 2, Groups E, F, and G. The enclosure is specifically designed to prevent an explosion. The Monitor’s durable, long-life LEL catalytic sensor will last 5+ years without needing to be replaced.

PureAire Monitors feature an easy to read screen, which displays current gas levels, for at-a-glance observation by employees, who derive peace of mind from the Monitor’s presence and reliable performance. In the event of a solvent leak, PureAire’s Monitors will set off alarms, complete with horns and flashing lights, alerting personnel to evacuate the area. Alarm signals can tie into automatic shut-off valves and ventilation systems when solvent levels reach an unsafe threshold.

Our LEL Combustible Gas monitor can connect to multi-channel controllers, a remote display, or into building systems themselves.




Friday, March 12, 2021

When Freshness Counts – Modified Atmosphere Packaging

 


Centuries ago, merchants and shippers would place a lit candle inside barrels used to store biscuits before closing the lid. The idea was that the candle flame would deplete the oxygen inside the barrel to help keep the biscuits from spoiling. These days, the candle flame has been replaced by processes called Modified Atmosphere Packaging (MAP), which can be either active or passive. By altering the atmosphere inside food product packages, or by using specialized packaging films, today’s food processors can preserve freshness and taste; extend shelf-life; prevent oxidation, which can lead to food spoilage; and protect against crushing the food contents inside the packaging, all without the use of chemical additives, stabilizers, or even candles.

Why Use Modified Atmosphere Packaging?

Consumers want food that not only looks, tastes, and smells good, but is also convenient and lasts longer than a few days after purchase. In order to satisfy consumers, food packagers need to eliminate or, at least, control factors that contribute to food spoilage, including improper levels of moisture, temperature, or light; excessive oxygen (i.e., oxidation); and the growth of microorganisms (such as mold or pathogens that can lead to food-borne illnesses).

Spoiled food means lost revenues and lower profits for producers and intermediaries, higher food prices passed on to the consumer, and an environmental burden, as food waste reportedly contributes to some 8% of global greenhouse gas emissions.

How Does MAP Work?

Active modified atmosphere packaging works by changing the atmosphere inside food packaging, typically by the introduction of gases. For instance, carbon dioxide is often used to remove oxygen from inside the packaging of breads and other baked goods, in order to keep the products from going stale, prevent mold growth, and extend shelf-life.

Packaged foods with high-fat content, such as certain cheeses or fish high in fatty acids, require a high concentration of carbon dioxide to prevent mold growth and to prevent the cheese or fish from tasting rancid. However, excessive levels of carbon dioxide can make certain foods taste sour. To prevent that from occurring, food packagers may elect to use nitrogen, or a mixture of gases, instead of carbon dioxide alone.

Conversely, while certain meat, fish, and poultry require that all or almost all oxygen be removed from inside packaging and replaced with carbon dioxide and/or nitrogen to prevent microbial growth and spoilage, oxygen is actually added to some packaged meats, low-fat fish, and shellfish to prevent fading or loss of color, as well as to inhibit the growth of certain types of bacteria.

Adding nitrogen gas to packaging not only helps salty snack foods stay crispy and fresh by displacing the oxygen inside food packaging, but it also helps protect the contents from getting crushed or broken during transport of the products from manufacturing facilities to stores and, ultimately, to consumers’ pantries.

Fresh fruits and vegetables are often packaged by using a passive form of MAP which includes specialized, permeable packaging films. The permeable film allows the fresh produce to continue to respire (that is, breathe) after being harvested, but at a much slower rate than if it were still on the plant. Low oxygen levels, combined with carbon dioxide or nitrogen, help to preserve the freshness, taste, and appearance of fresh fruits and vegetables.

Proper Monitoring Can Preserve Food Products and Protect Packaging Personnel

Balancing the correct mixture of oxygen, carbon dioxide, and nitrogen is vital when it comes to food packaging. Too much or too little of a required gas can lead to foods that have unappetizing taste, smell, or appearance and, in baked goods, can promote mold growth, and staleness.

Moreover, food packagers and others working around carbon dioxide and nitrogen need to be aware of the potential safety risks associated with these odorless and colorless oxygen-depleting gases. According to the Occupational Safety and Health Administration (OSHA), an environment in which oxygen levels fall below 19.5 percent is considered an oxygen-deficient atmosphere and should be treated as immediately dangerous to health or life. When there is not enough oxygen in the air, persons working in the affected area may become disoriented, lose consciousness, or even suffocate due to the lack of sufficient oxygen.

Because carbon dioxide and nitrogen are devoid of odor and color, individuals working around these gases might well, in the absence of appropriate monitoring equipment, be unaware that a safety risk situation has developed.

PureAire Monitors

PureAire Monitoring Systems’ Dual Oxygen/Carbon Dioxide Monitor offers thorough air monitoring, with no time-consuming maintenance or calibration required. A screen displays current oxygen and carbon dioxide levels for at-a-glance reading by food packaging employees, who derive peace of mind from the Monitor’s presence and reliable performance.

In the event of a carbon dioxide or nitrogen gas leak, and a decrease in oxygen to an unsafe level, PureAire’s Monitor will set off an alarm, complete with horns and flashing lights, alerting personnel to evacuate the area.

PureAire’s Dual Oxygen/Carbon Dioxide Monitor is well-suited for facilities where gases such as carbon dioxide and nitrogen are used. Our Dual O2/CO2 monitor includes both a non-depleting, zirconium oxide sensor cell, to monitor oxygen levels, and a non-dispersive infrared (NDIR) sensor cell, to monitor carbon dioxide levels. PureAire’s O2/CO2 monitors can last, trouble-free, for over 10 years under normal operating conditions.



Tuesday, February 2, 2021

Safe Use of Liquid Nitrogen in Food Processing Plants

 


In December 2020,  two employees working at a Vernon, California food processing plant lost consciousness and died following an apparent liquid nitrogen leak. On January 28, 2021, there were several fatalities, and many other employees became sick, after being exposed to nitrogen gas when a liquid nitrogen line ruptured at a food processing plant in Gainesville, Georgia.According to the Occupational Safety and Health Administration (OSHA), a total of fourteen workers died from asphyxiation linked to nitrogen gas in twelve separate workplace accidents recorded between 2012 and 2020, and 2021 is already off to a sad start.  Tragically, these accidents illustrate the dangers of working with liquid nitrogen.

Importance of Liquid Nitrogen in Food Processing

Liquid nitrogen (LN2) is used in food processing in a number of applications, including grinding, mixing, coating, freezing, and packaging foods. Food processors may use liquid nitrogen in the production of a variety of foods, such as meat, poultry, seafood, fruits, vegetables, baked goods, and prepackaged meals. The very low temperature of LN2 is used to flash-freeze foods to help prevent microbial growth that can lead to food spoilage, and to maintain the foods’ original freshness, flavor, and textures.

Oxygen Monitors Can Reduce the Risk of Liquid Nitrogen Accidents

While the use of liquid nitrogen is important in food processing, it is not without risk. When liquid nitrogen is exposed to the air (which happens when leaks occur), it will evaporate, changing from a liquid to an oxygen-depleting gas. Oxygen deprivation can put employees in real danger if there are leaks from pressurized LN2 freezer lines, exhaust systems, or on-site storage containers. In the event of a liquid nitrogen leak, food processing workers could become disoriented, lose consciousness, or even suffocate from breathing oxygen-deficient air. Since LN2 is both odorless and colorless, workers would, in the absence of appropriate monitoring, have no way of knowing that there has been a liquid nitrogen leak.

However, by utilizing a top-quality oxygen deficiency monitor, food plant personnel can safely track oxygen levels and detect leaks before workers’ health is jeopardized.Best practice calls for oxygen deficiency monitors to be installed anywhere there is a risk of liquid nitrogen gas leaks. The monitor should be placed wherever liquid nitrogen is stored, and in all areas where liquid nitrogen is used. The monitoring equipment should include visual and audible alarms that would be activated in the event of liquid nitrogen leaks and a decrease in oxygen levels.

PureAire Monitors

PureAire Monitoring Systems’ line of oxygen deficiency monitors, including a water-resistant unit for facilities requiring daily wash-downs, offers thorough air monitoring, with no time-consuming maintenance or calibration required. In the event of a liquid nitrogen leak, and a decrease in oxygen to an unsafe level, PureAire’s oxygen deficiency monitor will set off an alarm, complete with horns and flashing lights, alerting personnel to evacuate the area. PureAire oxygen deficiency monitors are ideally suited for use in food processing facilities because the monitors can withstand temperatures as low as -40 Celsius. Each PureAire O2 monitor has an easy to read screen, which displays current oxygen levels, for at-a-glance reading by food processing employees, who derive peace of mind from the monitor’s presence and reliable performance.


Tuesday, December 8, 2020

Air Delivery of Super-Cooled COVID-19 Vaccines


There are several potential COVID-19 vaccines that may soon be available for widespread distribution. In particular, the United Kingdom has recently approved Pfizer’s vaccine, and the U.S. Food and Drug Administration is considering extending Emergency Use Authorization to the Pfizer and Moderna vaccines.

That is certainly promising news, but storage, transportation, and delivery of these potentially game-changing vaccines will be quite challenging, with the CEO of the International Air Transport Association describing the distribution of COVID-19 vaccines as “the largest and most complex logistical exercise ever” undertaken.

It is not just the huge numbers (literally, in the billions of doses) and vast geographic scope (worldwide, requiring delivery to every country on the planet) that make the COVID-19 vaccine distribution task so daunting, but both the Pfizer and Moderna vaccines must be stored and transported in strict climate-controlled environments (reportedly, at some -70 degrees Celsius for Pfizer, and -20 degrees Celsius for Moderna) as integral parts of the vaccines’ “cold chains.”

COVID-19 Vaccine Cold Chain

The U.S. Centers for Disease Control (the “CDC”) describes a cold chain as a temperature-controlled supply chain that includes all vaccine-related equipment and procedures. The vaccine cold chain begins with a cold storage unit at the vaccine manufacturing plant, extends to the transport and delivery of the vaccine (including proper storage at the provider facility), and ends with the administration of the vaccine to the patient. A breakdown in protocols anywhere along the cold chain could reduce the effectiveness of, or even destroy, a vaccine.

Given the extreme cold temperatures required within their cold chains by the Pfizer and Moderna vaccines (and, perhaps, other COVID-19 vaccines that may now be under development by other firms), various companies within the vaccine delivery network (including temperature-controlled container manufacturers, logistics specialists, storage facility operators, commercial airlines, and dry ice producers) have been hard at work for months to meet the challenges associated with safely storing and transporting billions of vaccine doses once, as now appears to be at hand, they finally become available for international distribution.

Creating Super-Cold Environments

Dry ice, which is the common name for solid (i.e., frozen) carbon dioxide, is often used in cold chains to maintain the very cold temperatures required to keep certain vaccines viable. At a temperature of approximately -78.5 degrees Celsius (equating to -109.3 degrees Fahrenheit), dry ice is significantly colder than frozen water (that is, conventional ice), making it ideal for transport and storage of those vaccines which require an extremely cold temperature environment.

Safety precautions are critical when shippers use dry ice in the transportation and storage of vaccines. Unlike conventional ice, dry ice does not melt into a liquid. Instead, dry ice “sublimates” (changes from a solid to a gas state), turning into carbon dioxide gas. In poorly ventilated, confined spaces, such as storage rooms, railway cars, trucks, and cargo holds in airplanes, carbon dioxide can build up, creating a potentially serious health risk to transportation workers, including ground and flight crews.

Certain vaccine manufacturers may elect to ship their vaccines in multi-layered, storage canisters chilled with liquid nitrogen, rather than dry ice. We note that the potential health risks associated with nitrogen leaks are similar to those that may be caused by dry ice sublimation.

Oxygen Deficiency Risks Associated with Super-Cooled Environments

Carbon dioxide (as is nitrogen) is an oxygen-depleting gas that is both odorless and colorless. As such, absent appropriate monitoring, personnel working with the transportation of COVID-19 and other vaccines kept frozen with dry ice or liquid nitrogen likely would be unable to detect if dry ice were to sublimate (causing CO2 levels to rise), or if there were a nitrogen gas leak, and an associated decrease in oxygen.

According to the Occupational Safety and Health Administration (OSHA), an environment in which oxygen levels fall below 19.5 percent is considered an oxygen-deficient atmosphere and should be treated as immediately dangerous to health or life. When there is not enough oxygen in the air, persons working in the affected area may become disoriented, lose consciousness, or even suffocate due to the lack of sufficient oxygen.

FAA Guidance/Increased Air Shipment Capacity/Risk Mitigation

On May 22, 2009, the U.S. Federal Aviation Administration (the “FAA”) issued Advisory Circular No. 91-76A to specifically address the risks associated with the sublimation of dry ice aboard aircraft and, historically, the FAA has permitted even widebody aircraft to carry only relatively small amounts (typically not exceeding 1-1.5 tons per flight) of dry ice in refrigerated and insulated containers.

However, The Wall Street Journal (the “WSJ”) reported on November 29, 2020, that, in order to maintain the ultra-cold temperatures required by Pfizer’s COVID-19 vaccine, United Airlines has recently sought, and obtained, FAA approval to carry up to 15, 000 pounds (7.5 tons) of dry ice per flight. In a December 2, 2020 interview with CNN, Josh Earnest, Chief Communications Officer with United Airlines, noted that the FAA approval will allow United to ship as many as 1.1 million doses of COVID-19 vaccines on each flight of its commercial 777 airplanes.

Notwithstanding the FAA’s relaxation of dry ice weight limits to permit United Airlines to help bring the COVID-19 pandemic under control, it remains focused on risks associated with air shipments of dry ice. In its November 29, 2020 reporting, the WSJ noted that “regulators restrict the amount of dry ice that can be carried on passenger jets because they typically lack the equipment to monitor and mitigate any leaked carbon dioxide.”

Fortunately, by utilizing a top-quality oxygen-deficiency monitor, vaccine storage and transportation personnel, including flight crews, can safely track levels of oxygen and detect (and react to) potentially dangerous low oxygen levels, whether caused by dry ice sublimation or a nitrogen gas leak.

PureAire Monitoring Systems, Inc.

PureAire Monitoring Systems’ Oxygen Deficiency Monitor offers thorough air monitoring, with no time-consuming maintenance or calibration required. A screen displays current oxygen levels, for at-a-glance reading by crew members, who derive peace of mind from the Monitor’s presence and reliable performance.

Built with zirconium oxide sensor cells, to ensure longevity, the Monitor can last, trouble-free for 10 years in normal working conditions.

Our Oxygen Deficiency Monitor does not rely on the partial pressure of oxygen to operate, meaning that the Monitor is not affected by the changing pressure inside an aircraft due to altitude changes. In the event that dry ice begins to sublimate (causing carbon dioxide levels to rise), or if there is a nitrogen leak, and oxygen decreases to unsafe levels, PureAire’s Monitor will set off an alarm, complete with horns and flashing lights, alerting flight personnel to take corrective action.

For over 20 years, PureAire Monitoring Systems has been an industry leader in manufacturing long-lasting, accurate, and reliable Oxygen Deficiency Monitors. We have dedicated ourselves to ensuring the safety and satisfaction of our clients, many of which have very sophisticated operating requirements. We are proud to note that NASA’s SOFIA-Stratospheric Observatory for Infrared Astronomy--a Boeing 747SP aircraft modified to carry a 2.7 meter (106 inch) reflecting telescope--carries onboard a PureAire Oxygen Deficiency Monitor.