Why is gas detection crucial for drink dispense systems

Dispense gas known as beer gas, keg gas, cellar gas or pub gas is used in bars and restaurants as well as the leisure and hospitality industry. Using dispense gas in the process of dispensing beer and soft drinks is common practice worldwide. Carbon dioxide (CO₂) or a mix of CO₂ and nitrogen (N₂) is used as a way of delivering a beverage to the ‘tap’. CO₂as a keg gas helps to keep the contents sterile and at the right composition aiding dispensing.

Gas Hazards

Even when the beverage is ready to deliver, gas-related hazards remain. Those arise in any activity at premises that contain compressed gas cylinders, due to the risk of damage during their movement or replacement. Additionally, once released there is a risk of increased carbon dioxide levels or depleted oxygen levels (due to higher levels of nitrogen or carbon dioxide).

CO₂occurs naturally in the atmosphere (0.04%) and is colourless and odourless. It is heavier than air and if it escapes, will tend to sink to the floor. CO₂ collects in cellars and at the bottom of containers and confined spaces such as tanks and silos. CO₂ is generated in large amounts during fermentation. It is also injected into beverages during carbonation – to add the bubbles. Early symptoms of exposure to high levels of carbon dioxide include dizziness, headaches, and confusion, followed by loss of consciousness. Accidents and fatalities can occur in extreme cases where a significant amount of carbon dioxide leaks into an enclosed or poorly ventilated volume. Without proper detection methods and processes in place, everyone entering that volume could be at risk. Additionally, personnel within surrounding volumes could suffer from the early symptoms listed above.

Nitrogen (N₂) is often used in the dispensing of beer, particularly stouts, pale ales and porters, it also as well as preventing oxidisation or pollution of beer with harsh flavours. Nitrogen helps push the liquid from one tank to another, as well as offer the potential to be injected into kegs or barrels, pressurising them ready for storage and shipment. This gas is not toxic, but does displace oxygen in the atmosphere, which can be a danger if there is a gas leak which is why accurate gas detection is critical.

As nitrogen can deplete oxygen levels, oxygen sensors should be used in environments where any of these potential risks exist. When locating oxygen sensors, consideration needs to be given to the density of the diluting gas and the “breathing” zone (nose level). Ventilation patterns must also be considered when locating sensors. For example, if the diluting gas is nitrogen, then placing the detection at shoulder height is reasonable, however if the diluting gas is carbon dioxide, then the detectors should be placed at knee height.

The Importance of Gas Detection in Drinks Dispense Systems

Unfortunately, accidents and fatalities do occur in the drinks industry due to gas hazards. As a result, in the UK, safe workplace exposure limits are codified by the Health and Safety Executive (HSE) in documentation for the Control of Substances Hazardous to Health (COSHH). Carbon dioxide has an 8-hour exposure limit of 0.5% and a 15-minute exposure limit of 1.5% by volume. Gas detection systems help to mitigate gas risks and allow for drinks manufacturers, bottling plants and bar/pub cellar owners, to ensure the safety of personnel and demonstrate compliance to legislative limits or approved codes of practice.

Oxygen Depletion

The normal concentration of oxygen in the atmosphere is approximately 20.9% volume. Oxygen levels can be dangerous if they are too low (oxygen depletion). In the absence of adequate ventilation, the level of oxygen can be reduced surprisingly quickly by breathing and combustion processes.

Oxygen levels may also be depleted due to dilution by other gases such as carbon dioxide (also a toxic gas), nitrogen or helium, and chemical absorption by corrosion processes and similar reactions. Oxygen sensors should be used in environments where any of these potential risks exist. When locating oxygen sensors, consideration needs to be given to the density of the diluting gas and the “breathing” zone (nose level). Oxygen monitors usually provide a first-level alarm when the oxygen concentration has dropped to 19% volume. Most people will begin to behave abnormally when the level reaches 17%, and hence a second alarm is usually set at this threshold. Exposure to atmospheres containing between 10% and 13% oxygen can bring about unconsciousness very rapidly; death comes very quickly if the oxygen level drops below 6% volume.

Our Solution

Gas detection can be provided in the form of both fixed and portable detectors. Installation of a fixed gas detector can benefit a larger space such as cellars or plant rooms to provide continuous area and staff protection 24 hours a day. However, for worker safety in and around cylinder storage area and in spaces designated as a confined space, a portable detector can be more suited. This is especially true for pubs and beverage dispensing outlets for the safety of workers and those who are unfamiliar in the environment such as delivery drivers, sales teams or equipment technicians. The portable unit can easily be clipped to clothing and will detect pockets of CO₂using alarms and visual signals, indicating that the user should immediately vacate the area.

For more information about gas detection in drink dispense systems, contact our team.

Industry Overview: Food and Beverage

The food and beverage (F&B) industry includes all companies involved in processing raw food materials, as well as those packaging and distributing them. This includes fresh, prepared foods as well as packaged foods, and both alcoholic and non-alcoholic beverages.

The food and beverage industry is divided into two major segments, which are the production and the distribution of edible goods. The first group, production, includes the processing of meats and cheeses and the creation of soft drinks, alcoholic beverages, packaged foods, and other modified foods. Any product meant for human consumption, aside from pharmaceuticals, passes through this sector. Production also covers the processing of meats, cheeses and packaged foods, dairy and alcoholic beverages. The production sector excludes foods and fresh produce that are directly produced via farming, as these fall under agriculture.

The manufacture and processing of food and beverages create substantial risks of fire and toxic gas exposure. Many gases are used for baking, processing and refrigerating foods. These gases can be highly hazardous – either toxic, flammable, or both.

Gas Hazards

Food Processing

Secondary food processing methods includes fermentation, heating, chilling, dehydration or cooking of some kind. Many types of commercial food processing consist of cooking, especially industrial steam boilers. Steam boilers are usually gas-fired (natural gas or LPG) or use a combination of gas and fuel oil. For gas-fired steam boilers, natural gas consists mainly of methane (CH₄), a highly combustible gas, lighter than air, which is piped directly into boilers. In contrast, LPG consists mainly of propane (C₃H₈), and usually requires an on-site fuel storage tank. Whenever flammable gases are used on site, forced mechanical ventilation must be included in storage areas, in case of leakage. Such ventilation is usually triggered by gas detectors that are installed near boilers and in storage rooms.

Chemical Disinfection

The F&B industry takes hygiene very seriously, as the slightest contamination of surfaces and equipment can provide an ideal breeding ground for all kinds of germs. The F&B sector therefore demands rigorous cleaning and disinfection, which must meet industry standards.

There are three methods of disinfection commonly used in F&B: thermal, radiation and chemical. Chemical disinfection with chlorine-based compounds is by far the most common and effective way to disinfect equipment or other surfaces. This is because chlorine-based compounds are inexpensive, fast acting and effective against a variety of microorganisms. Several different chlorine compounds are commonly used, of which include hypochlorite, organic and inorganic chloramines, and chlorine dioxide. Sodium hypochlorite solution (NaOCl) is stored in tanks while chlorine dioxide (ClO₂) gas is usually generated on site.

In any combination, chlorine compounds are hazardous and exposure to high concentrations of chlorine can cause severe health issues. Chlorine gases are usually stored on site and a gas detection system should be installed, with a relay output to trigger ventilation fans once a high level of chlorine is detected.

Food Packaging

Food packaging serves many purposes; it allows food to be transported and stored safely, protects food, indicates portion sizes and provides information about the product. To keep food items safe for a long time, it is necessary to remove oxygen from the container because otherwise, oxidation will occur when the food comes into contact with oxygen. The presence of oxygen also promotes bacterial growth, which is harmful when consumed. However, if the package is flushed with nitrogen, the shelf life of packaged food can be extended.

Packagers often use nitrogen (N₂) flushing methods for preserving and storing their products. Nitrogen is a non-reactive gas, non-odorous and non-toxic. It prevents oxidation of fresh food with sugars or fats, stops the growth of dangerous bacteria and inhibits spoilage. Lastly, it prevents packages from collapsing by creating a pressurized atmosphere. Nitrogen can be generated on site using generators or delivered in cylinders. Gas generators are cost effective and provide an uninterrupted supply of gas. Nitrogen is an asphyxiant, capable of displacing oxygen in air. Because it has no smell and is non-toxic, workers may not become aware of low oxygen conditions before it is too late.

Oxygen levels below 19% will cause dizziness and loss of consciousness. To prevent this, oxygen content should be monitored with an electrochemical sensor. Installing oxygen detectors in packaging areas ensures the safety of workers and early detection of leaks.

Refrigeration Facilities

Refrigeration facilities in the F&B industry are used to keep food cool for long periods of time. Large-scale food storage facilities often use cooling systems based on ammonia (> 50% NH₃), as it is efficient and economical. However, ammonia is both toxic and flammable; it is also lighter than air and fills up enclosed spaces rapidly. Ammonia can become flammable if released in an enclosed space where a source of ignition is present, or if a vessel of anhydrous ammonia is exposed to fire.

Ammonia is detected with electro-chemical (toxic) and catalytic (flammable) sensor technology. Portable detection, including single- or multi-gas detectors, can monitor instantaneous and TWA exposure to toxic levels of NH3. Multi-gas personal monitors have been shown to improve workers’ safety where a low-range ppm for routine system surveys and flammable range is used during system maintenance. Fixed detection systems include a combination of toxic- and flammable-level detectors connected to local control panels – these are usually supplied as part of a cooling system. Fixed systems can also be used for process over-rides and ventilation control.

Brewing and Drinks Industry

The risk involved in the manufacture of alcohol involves sizable manufacturing equipment which can be potentially harmful, both to operate and because of the fumes and vapours that can be emitted into the atmosphere and subsequently impact the environment. Ethanol is the main combustible hazard found within distilleries and breweries is the fumes and vapours produced by ethanol. With the capacity to be emitted from leaks in tanks, casks, transfer pumps, pipes and flexible hoses, ethanol vapour is a very real fire and explosion hazard faced by those in the distillery industry. Once the gas and vapour is released into the atmosphere, it can quickly build and pose a danger to the health of workers. It is worth noting here however, that the concentration required to cause harm to workers’ health has to be very high. With this in mind, the more significant risk from ethanol in the air is that of explosion. This fact reinforces the importance of gas detection equipment to recognise and remedy any leaks straight away, so as to avoid disastrous consequences.

Packaging, Transport and Dispensing

Once wine is bottled and beer is packaged, they must be delivered to the relevant outlets. This commonly includes distribution companies, warehousing and in the case of breweries, draymen. Beer and soft drinks use carbon dioxide or a mix of carbon dioxide and nitrogen as a way of delivering a beverage to the ‘tap’. These gases also give beer a longer-lasting head and improve the quality and taste.

Even when the beverage is ready to deliver, gas-related hazards remain. Those arise in any activity at premises that contain compressed gas cylinders, due to the risk of increased carbon dioxide levels or depleted oxygen levels (due to high levels of nitrogen). Carbon dioxide (CO₂) occurs naturally in the atmosphere (0.04%). CO₂  is colourless and odourless, heavier than air and if it escapes, will tend to sink to the floor. CO₂ collects in cellars and at the bottom of containers and confined spaces such as tanks and silos. CO₂  is generated in large amounts during fermentation. It is also injected into beverages during carbonation.

To find out more on the gas hazards in food and beverage production visit our industry page for more information.

Oxygen Depletion Risks from Nitrogen in Pharmaceutical Processing

Within the air, a normal concentration of oxygen is 21%, while nitrogen makes up 78% of the rest of the atmosphere along with some trace gases. Inert gases such as nitrogen, argon and helium although aren’t toxic, they do not help to support human breathing. These are odourless, colorless and tasteless making them undetectable. An increase in the volume of any other gases that are not oxygen can lead to a circumstance in which individuals may be at risk of asphyxiation which can cause serious injury or even death. This removal of oxygen gas in the air we breathe makes having an oxygen depletion sensor not just useful, but essential to maintaining life.

How is Nitrogen used to control oxygen levels?

Nitrogen (N2) can be used to control levels of oxygen in a laboratory. When carrying out tasks within the pharmaceutical industry, when transferring products or packaging process, nitrogen is used. Nitrogen is used to take oxygen away from the packaging prior to it being sealed, to make certain the product is preserved. As a result of this the need for an oxygen deficiency monitor is very important. Fixed or portable devices have the ability to detect oxygen levels within a laboratory, plant or utility room. Fixed gas detection systems are suitable for monitoring an area or room, whereas a portable gas detector is designed to be worn on the person within your breathing area.

What are the Risks of Oxygen depletion?

There are three main reasons why monitors are needed; it is essential to detect oxygen deficiencies or enrichment as too little oxygen can prevent the human body from functioning leading to the worker losing consciousness. Unless the oxygen level can be restored to a normal level the worker is at risk of potential death. An atmosphere is deficient when the concentration of O2 is less than 19.5%. Consequently, an environment that has too much oxygen in it is equally dangerous as this constitutes a greatly increased risk of fire and explosion, this is considered when the concentration level of O2 is over 23.5%.

In the absence of adequate ventilation, the level of oxygen can be reduced surprisingly quickly by breathing and combustion processes. Oxygen levels may also be depleted due to dilution by other gases such as carbon dioxide (also a toxic gas), nitrogen or helium, and chemical absorption by corrosion processes and similar reactions. Oxygen sensors should be used in environments where any of these potential risks exist. When locating oxygen sensors, consideration needs to be given to the density of the diluting gas and the “breathing” zone (nose level). For example, helium is lighter than air and will displace the oxygen from the ceiling downwards whereas carbon dioxide, being heavier than air, will predominately displace the oxygen below the breathing zone. Ventilation patterns must also be considered when locating sensors.

Oxygen monitors usually provide a first-level alarm when the oxygen concentration has dropped to 19% volume. Most people will begin to behave abnormally when the level reaches 17%, and hence a second alarm is usually set at this threshold. Exposure to atmospheres containing between 10% and 13% oxygen can bring about unconsciousness very rapidly; death comes very quickly if the oxygen level drops below 6% volume. Oxygen sensors are often installed in laboratories where inert gases (e.g., nitrogen) are stored in enclosed areas.

How do Fixed or Portable Devices Detect Oxygen?

Crowcon offer a range of portable monitors; Gas-Pro portable multi gas detector offers detection of up to 5 gases in a compact and rugged solution. It has an easy-to-read top mount display making it easy to use and optimal for confined space gas detection. An optional internal pump, activated with the flow plate, takes the pain out of pre-entry testing and allows Gas-Pro to be worn either in pumped or diffusion modes.

T4 portable 4-in-1 gas detector provides effective protection against oxygen depletion. T4 multi gas detector now comes with improved detection of pentane, hexane and other long chain hydrocarbons. Offering you compliance, robustness and low cost of ownership in a simple to use solution. T4 contains a wide range of powerful features to make everyday use easier and safer.

Crowcon’s fixed detector XgardIQ is an intelligent and versatile fixed detector and transmitter compatible with Crowcon’s full range of sensor technologies. Available fitted with a variety of sensors for fixed flammable, toxic, oxygen or H2S gas detection. Providing analogue 4-20mA and RS-485 Modbus signals as standard, XgardIQ is optionally available with Alarm and Fault relays and HART communications. The 316 stainless steels are available with three M20 or 1/2“NPT cable entries. This device is also (SIL-2) Safety integrity level 2 certified fixed detector.