Gas Monitoring in Frozen Food Storage Applications

Gases used in refrigeration including carbon dioxide, nitrogen, oxygen, helium, and ammonia play an important role in frozen food and food storage applications. Whether the gases are used to maintain quality, preservation, freezing, or extend shelf life, they have created numerous benefits for consumers.

When it comes to frozen food storage and preservation, the use of these gases is critical. However, gas safety is just as critical for those working around these gases.

The Role of Gases in the Frozen Food Storage Applications

The technology of using compressed gases for refrigeration began in the late 19th century. In the early 1900's home refrigerators using small gas compressors were developed. However, it was not until World War II when the military required large quantities of food to be transported and stored efficiently. As Napoleon said, “An army marches on its stomach.” In addition to dried and canned foods, soldiers wanted fresh food from home. This helped start the future industrial use of gases for food storage and preservation.

As the need for preserving food increased for both wartime and civilian use, the use of gases for quick freezing, packaging and transport at an industrial scale became important. Gases like carbon dioxide, nitrogen, oxygen, helium, and ammonia, were tested to further advance food quality and create benefits for consumers.

Common Gases in Frozen Food Storage and Their Risks

• Liquid Nitrogen (LN2) is often used for quick freezing of food products known as cryogenic freezing. It has an extremely low boiling point of -196° degrees Celsius (-321° degrees Fahrenheit), making it highly effective for rapidly reducing the temperature of food.
• Nitrogen (N2) is used in several ways in the frozen food industry, for inert gas blanketing to displace oxygen and create a protective atmosphere in food packaging and to prevent oxidation. With the use of nitrogen, food manufacturers can preserve and maintain food quality as well as increase the shelf life of fresh food.
• Carbon Dioxide (CO2) can be used as a refrigerant in modified atmosphere packaging (MAP) to control the gas composition or to extend the shelf life and preserve product quality. It can also be used to carbonate frozen beverages and add flavor to carbonated products. Further, CO2 is also used as dry ice for food refrigeration in transit and short-term storage.
• Oxygen (O2). While oxygen is not used in frozen food processing, its exclusion through modified atmosphere packaging or inert gas blanketing helps prevent oxidation and maintains the quality of frozen products.
• Helium (He). Although less common, helium can be used in cryogenic cooling and freezing applications. Liquid helium is extremely cold and non-reactive, making it suitable for specific freezing processes. However, it's recent scarcity has limited its use in food preservation.
• Ammonia (NH3) is used in many industrial refrigeration systems for maintaining low temperatures in storage and transportation of frozen food products. However, it is highly toxic and flammable. In addition, long-term exposure can lead to irreversible side effects.

Which Frozen Food Storage Applications use Gas?

Food production, preservation, flash freezing and transportation involve many industries and are applied to a wide range of food products. Below we highlight some of the industries in food production that utilize preservation, cold storage, freezing, and transport using gas.

Modified Atmosphere Packaging

Modified atmospheric conditions are now commonplace in the packaging, storage, and transport of all kinds of food products, from fresh to frozen produce. High carbon dioxide and reduced oxygen levels are used to slow spoilage, to kill insect species, and to limit microorganisms that would otherwise grow on stored foodstuffs.

High nitrogen concentrations can additionally be used as a humidity control for dried foods as it can help preserve food quality while extending lifetime. By using gas mixtures to replace insecticides, and the addition of preservatives such as nitrites to meats, modified atmosphere packaging offers a versatile way to preserve foods without the need to add additional chemicals or processing.

Beverage Industry

The carbonation of beverages, such as soft drinks, sparkling water, and beer, involve the use of carbon dioxide (CO2) gas to create effervescence. In addition, nitrogen can also be used to give a frothy texture to certain beverages, such as stout beer or nitro coffee. Blanketing with gases, usually nitrogen, can be used in addition to create a protective atmosphere above the liquid in storage tanks.

Baking and Pastry Production

In the baking and pastry industry, carbon dioxide is produced to help dough rise, resulting in baked goods like bread, cakes, and pastries with a light, airy texture. When fillings or toppings, such as those in quiches, expand and set during baking, gas production can also play a role in the desired texture or appearance. Nitrogen is also for cooling, chilling, and food freezing.

Dairy Industry

The dairy industry uses gases in various applications, including the injection of nitrogen gas into milk to remove oxygen, extend shelf life, and preserve the flavor and nutritional quality. Gases may also be used to control the temperature and humidity in dairy storage facilities, ensuring that dairy products are stored in the appropriate conditions to maintain their quality and safety.

Freezing and Cryogenic Cooling

Gases such as liquid nitrogen (LN2) are used for rapid freezing and cryogenic cooling in various food industries to preserve the quality of products during the freezing process. This process involves lowering the temperatures of food to a point where most of the water in the food turns to ice. Freezing also prevents microbial growth and enzymatic activity that can spoil the food. There are different methods of freezing, such as air-blast freezing, contact freezing, and cryogenic freezing.

Animal Processing and Euthanasia

The euthanasia of livestock in poultry farms, in dog pounds and in animal testing labs can use carbon dioxide to stun animals before slaughter. CO2 induces unconsciousness and alleviates pain and distress.

Food Distribution and Transportation

Transportation and delivering of food products to consumers, retailers, or end users requires maintaining the "cold chain," a system of refrigerated storage and transportation that ensures the food remains safe throughout its journey. For example, nitrogen is often used to create an inert atmosphere during food storage that prevents oxidation and microbial growth.

Canning and Food Preservation

Gases such as nitrogen can be used to create a protective atmosphere in canned food products to prevent oxidation and maintain product quality. In the canning process, inert gases like nitrogen are used to displace oxygen within the cans before sealing. This inert gas blanket prevents the oxidation of the food, which can lead to spoilage, off-flavors, and color changes.

Frozen Food Compressed Gas Hazards

Within food production and manufacturing there are several sub-industries we previously touched on, all that use compressed gases as an essential component of their day-to-day process. The use of these compressed gases can present various hazards, and it’s essential to manage these risks by use of gas safety monitoring to ensure the safety of both workers and consumers.

Common hazards associated when using compressed gases include pressure, asphyxiation, convulsions, toxicity and inadequate ventilation. Because gases are stored at such high pressures, if not properly handled, they can lead to ruptured containers, leaks, or even explosions.

Workers in the food production, preservation, and chilling industries may often be at risk of injury from flying debris or the force of the gas release. In addition, some gases used in food production, like nitrogen and carbon dioxide, can displace oxygen in confined spaces. This can lead to inadequate ventilation, oxygen deficiency, or pose a risk of asphyxiation to workers and those near gas hazard points.

For some gases that react with food products or other substances in the production environment, they too can also lead to potential negative health effects or chemical reactions due to hazardous byproducts. This can further affect food quality, product, and overall safety for the consumer and end user. To mitigate these hazards, it is critical to follow strict safety procedures when dealing with compressed gases and be able to mitigate hazards before they occur.

Below we highlight the main hazard locations you should know when working near or around dangerous compressed gases in the field.

1. Cold Storage Areas: Cryogenic gases like liquid nitrogen are used for rapid cooling and freezing of food products. These gases can be extremely cold and can cause frostbite or cryogenic burns if they meet skin or eyes. These areas can present fire safety concerns. For instance, a fire broke out at Buffalo Farms Freezer and Cold Storage, a fruit-packing and storage warehouse in Hammonton, New Jersey, which reportedly started from hot work activities taking place at the facility.
2. Post-Lethality Region: After thermal processing, food products are typically exposed to the environment prior to freezing in an area commonly referred to as the post-lethality region. This area is a critical component of Listeria monocytogenes control.
3. Gas Supply and Storage Areas: The area where compressed gas cylinders are stored and maintained can be dangerous if not managed properly. Leaking cylinders, improper storage, and mishandling pose risks to workers in this area.
4. Food Production and Packaging Line: The use of compressed gases for modified atmosphere packaging is common. These gases can be used inside the food packaging yet when altered, can carry risks associated with the handling and storage of these gases. Gas leaks or incorrect gas mixtures can affect product quality and safety.
5. Laboratories and Quality Control: Food production facilities often have laboratories for quality control and testing. Some of these labs may use compressed gases for various analytical processes, and potential hazards must be managed in these areas.
6. Food Transportation and Handling: The transport and handling of compressed gas cylinders to and from various areas in a food production facility poses risks if not done carefully. Falling cylinders can cause injuries, leaks, and damage.

To mitigate risks in these areas, food production facilities should implement safety measures, including proper training, the use of appropriate gas safety monitoring, personal protective gear, regular inspections, and overall adherence to safety standards. Additionally, facilities should conduct risk assessments and emergency response planning to address potential compressed gas hazards effectively.

Gas Monitoring for Cold Rooms and Walk-In Freezers

To minimize downtime and spoilage while protecting people:

• CO2 Monitoring: Use fixed CO2 storage safety alarms near cylinders, evaporators, floor-level low points, and return-air paths.
• O2 Deficiency Monitoring: Install oxygen depletion alarms in rooms using LN2 or N2 blanketing (MAP lines, spiral freezers, cryo tunnels).
• Ammonia (NH3) Detection: Position toxic gas sensors in machinery rooms and potential leak sources; integrate to auto-ventilation and emergency shut-off.
• Alarm Staging: Configure pre-alarm for investigation and high-alarm to trigger ventilation/evacuation and notify responders.

How CO2 and Ammonia Gas Safety Systems Protect Workers and Ensure OSHA Compliance

The frozen food industry depends heavily on gases like carbon dioxide (CO2), ammonia (NH3), and nitrogen (N2) for refrigeration, preservation, and transport; but these same gases can create serious occupational hazards.

According to OSHA, confined spaces such as cold rooms, walk-in freezers, and compressor areas require continuous gas monitoring to prevent oxygen deficiency and hazardous exposure.

Installing fixed gas detection systems is the most effective way to protect workers and maintain compliance with OSHA and NIOSH standards. CO2 monitors positioned near cylinders, evaporators, and floor-level return air paths detect rising CO2 concentrations in real time, while ammonia detectors placed in machinery rooms and compressor spaces can automatically trigger ventilation and emergency shutdown systems. These early warning alarms provide critical minutes for staff to evacuate safely before exposure levels become dangerous.

Beyond safety, continuous gas monitoring supports operational efficiency and product integrity. By ensuring gases remain within safe thresholds, food processors reduce the risk of spoilage, maintain refrigeration performance, and meet strict food safety requirements. From large-scale cold storage facilities to smaller walk-in freezers, CO₂ and ammonia monitoring are no longer optional—they’re essential tools for regulatory compliance, employee health, and business continuity.

Why Gas Monitoring is Crucial for Frozen Food Storage Facilities

To provide further perspective, there have been numerous accidents involving gas leaks that have been reported worldwide, hospitalizing hundreds, and even resulting in fatalities.

Typical gas leak accidents involve system wear or failure of components, lack of preventative maintenance guidelines, and lack of gas detection solutions.

For frozen food production and preservation, only a gas safety monitor or a analyzer can help mitigate hazards, maintain preservation of product and ensure employee safety for your staff and establishment.

Because gases like CO2 are so dangerous and can’t be detected by the human eye, the National Institute for Occupational Health and Safety (NIOSH) has put standards in place. These standards state that CO2 levels of 40,000ppm (4%) are immediately dangerous to life and health within 10-hour workplace exposure limits.

In fact, due to such severe incidents around the globe, the Occupational Safety and Health Administration (OSHA) has put together a list of standards for businesses to abide by when entering confined or potentially oxygen deficient spaces.

These standards state, “For any employee who must enter a confined space or potentially oxygen deficient space may require a low oxygen deficiency alarm, a respirator, or personal protection equipment." OSHA also defines an oxygen deficient atmosphere, as any atmosphere where less than 19.5% oxygen is found by volume. At lower levels, severe negative health effects can occur as follows:

It’s a popular myth in the industry that monitoring for low oxygen levels will give an appropriate carbon dioxide reading. The reality, however, is that carbon dioxide can escalate to danger before any oxygen sensor would ever alarm, because CO2 settles first at the floor and oxygen sensors are most typically mounted at eye level.

Like NIOSH, OSHA also sets a current standard for those working, using, or storing hazardous carbon dioxide gases. The current OSHA standard is 5000 ppm as an 8-hour time weighted average (TWA) concentration. Concentrations of 10 (100,000 ppm) or more can further produce unconsciousness, seizures, and even fatality.

Normal levels of CO2 in fresh air are approximately 400 ppm (parts per million) or 0.04% CO2 in air by volume. The table below shows the effects of increased CO2 levels in an enclosed space as a percentage of air by volume.

Read the complete list of OSHA, NIOSH and other CO2 standards here.

Overall, when it comes to hazardous gases like nitrogen, oxygen, ammonia, and carbon dioxide; extreme exposure can be fatal. If a canister or supply line begins to leak, gas will soon enter the entire facility or if a fitting is loose, this can mean severe danger for anyone in the establishment. When this happens, hazardous gas can displace the air and since no one can tell of the leak, only a real-time gas safety monitor can indicate that danger is near.

These gas leaks, as unfortunate as they are, are common in enclosed spaces such as food production rooms, freezers, processing lines, and chillers. The easiest way to protect employees’ safety is by installing a gas safety monitor to track gas levels, sound an alarm, and warn all employees near potential leak points. These safety monitors operate by tracking gas concentrations in real-time, sounding an alarm for high concentrations, and ensuring peace of mind for your staff, employees, and establishment.

Where to Install Gas Monitors in Frozen Food Facilities

Priority locations:

1. Refrigeration machinery rooms (NH3/toxic gas sensors)
2. Cold rooms/walk-ins (CO2 low-mount; O2 at breathing height)
3. MAP packaging lines (CO2/N2; O2 deficiency)
4. Cylinder/tank storage (CO2, N2, NH3)
5. Loading docks & corridors connected to cold zones
6. Confined spaces (entries require portable multi-gas testing)

Configuration tips

• Use relay outputs to control fans and valves.
• Add strobe lights in high-noise areas.
• Use remote displays to warn people before entering potentially hazardous areas.
• Maintain event logs for audits and RCA.

Gas Safety Monitors

Gas detection monitoring is a critical piece of safety for food production, preservation, and chilling industry professionals. However, for every application, there are several core factors that individuals should know specifically when choosing a device. If you need to monitor the lack of oxygen or nitrogen in space, look for an oxygen deficiency safety alarm.

If you need to measure high concentrations of carbon dioxide, look for a carbon dioxide safety alarm. The issue isn't so much finding the right gas detection device but choosing the right device from the many choices you have.

Gas detectors typically come in two options – fixed or portable gas detection. When we look at fixed or wall-mounted gas detectors as a category, these devices are most identified for general installation in a commercial facility. They detect leaks as well as provide an early warning of higher than normal gas concentration levels.

Mounted in one location, these devices are permanent fixtures used when constant gas detection is required. Fixed gas detection systems also are typically configured using relays and specified alarm settings to meet code requirements, or OSHA, NIOSH, and CGA standards. These settings ensure that fixed gas detectors respond quickly and accurately to atmospheric hazards. In addition, relays provide several functionalities that can be vital to saving lives, including:

• Triggering an exhaust fan
• Opening ventilation
• Triggering valves that shut-off gas supply
• Notifying emergency services by wiring to a fire control panel

Alternatively, handheld or portable gas detectors are used when detection is temporary, when fixed detection is not an option, or for personal gas safety and protection.

Portable gas detectors are also used in confined space entries. For instance, individuals that are working in and out of cold storage facilities or who transport dry ice find these devices critical and useful for their day-to-day operation.

Best Practices for Implementing Gas Safety Monitors in Frozen Food Storage

Implementing gas safety monitors in frozen food storage facilities is vital for ensuring both product quality and worker safety. To effectively monitor gases like carbon dioxide (CO₂) and ammonia (NH₃), which are often used in refrigeration systems, it's essential to place gas detectors strategically throughout the storage area.

Positioning monitors near refrigeration units, entry points, and areas with potential leak risks ensures early detection, preventing dangerous gas accumulations. Regular calibration and maintenance of these monitors further guarantee their accuracy, enabling quick responses to hazardous conditions.

Another best practice is integrating gas monitors with an automated alarm system that can immediately notify staff of a leak or abnormal gas levels. Gas safety monitors like the Remote CO2 Storage Safety 3 Alarm, help facilitate rapid evacuation and corrective actions, minimizing the risk of spoilage and ensuring the safety of workers.

By following these best practices, frozen food storage facilities can maintain a safe environment and comply with industry regulations. If you need more assistance to ensure you are choosing the right gas detection safety monitor for your industry, contact a CO2Meter expert today.