Think about the food you eat and the drinks you consume daily. Is your food or beverage safe to consume? Can you trust the food and beverage industry to produce contaminant-free products? The purpose of this article is to provide insight into the workings of air filtration and ventilation in food and beverage processing, production, and packaging.
How is air filtration used in the food industry?
There are a wide variety of foods and food production processes, probably more than any other industrial segment. If you think about all the different types of food you eat, each is produced in a different way and often in vastly different facilities. Unlike hospitals for example, which are very similar to one another, food and beverage facilities often do not look anything like one another, inside or outside.
High purity requirements for food and beverages
In food and beverage, there are very high purity requirements such as in aseptic processing. Good examples of this production technique would be yogurt, fruit pouches, pudding, or protein-boosting drinks. These are often long shelf life products that have to be produced in an exceptionally clean environment because ultimately, whatever is in the packaging stays in that packaging until we, the consumers, open it up.
Air filtration expert Mark Davidson states, “It’s been an amazing development over the years that producers have learned how to process food and beverages aseptically and create products with a much longer shelf life. It has helped tremendously in areas of the world where there is a food security problem because the refrigeration to store cold food doesn’t exist in great abundance.”
But spoilage is still a major consideration for many foods and beverages. Davidson continues, “When you open a package, anything that was in that package when it was sealed, is still going to be in there. So for these long-shelf-life foods, when you seal that package, it needs to be aseptic. In other words, it needs to be in an environment as free from germs or pathogens as possible, because whatever is in there, has free reign to grow. So aseptic processing requires an extremely clean environment. Like a cleanroom inside of small packaging.”
There are other applications that also have high purity requirements, such as frozen food, peanut butter products, and certain types of fish for example. But there are other production methods in large facilities that don’t have robust air filtration. This can be because complex air filtration is not necessary due to the lower threat of contamination, such as in popcorn and other grain production.
What contaminants are present in bottling facilities in the beverage industry?
Regarding soft drinks and the like, from an air filtration point of view, there are a few different areas of concern. The first thing is the ambient plant air. The rooftop air handling units that bring air into the plant are similar to any other industrial facility. Air must be pulled into the plant for ventilation. The contaminants of concern would be whatever is in the environment near the facility. For example, the exhaust of either that facility or another facility nearby, or air pollution from other sources.
A bottling plant that produces bottled water, for example, could be downwind from something like a cement kiln. That would need to be considered when determining what type of air filtration is needed due to the harmful airbourne contaminants.
The second thing is whether it is aseptic, or just in a contained packaging area. Water doesn’t necessarily need to be aseptically packaged, but it does need to be packaged in a controlled space that may have a HEPA filter above the filling area.
For some bottling processes, it is very important to have an air filter where the bottle filling occurs. For example, in a large contained area with a dispensing nozzle inside . In this process, a conveyor line delivers bottles into the contained area, the nozzle dispenses the liquid into the bottle and another machine caps it. The dispensing space is generally positively pressurized when compared to the surrounding areas. The pressurized and filtered air is used to keep contaminants out of the contained area so the bottling environment is as clean as possible.
There is air filtration required to protect the area where bottling occurs. The conveyor fans used to move empty bottles from station to station should have a stage of filtration before the fans to properly filter the air being blown directly into the empty bottles.
Is soda packaged aseptically?
Carbonated drink ingredients like popular sodas don’t necessarily lend themselves to aseptic processing, but as the drink ingredients expand to include pulp, fruit bits or other additions, a wider variety of processing techniques are options.
What is required in air filtration for food and beverage safety?
There are non-profit associations in the U.S. and Canada that unite industry stakeholders, and their approach is very technical. Davidson states, “I’ve been to their technical conferences, and honestly, I would put these people up against organizations in any of the life sciences fields that I have experienced. The non-profit associations understand the risks with aseptic food processing because, if you make a bad computer chip due to dirty air, you’ve got a bad computer chip. There’s an expense, but chips can be replaced. However, if you make a bad food product and that food is contaminated, an applesauce pouch for example, a child could open and squeeze the contents down their throat without even stopping. If the product is contaminated, you have a serious public safety issue.”
People in the aseptic food processing industry are very careful and methodical in their approach. They understand what is needed to do to produce safe products because the consequences, which go beyond costs, are so significant. This is not an industry that takes shortcuts.
What contaminants do you have to worry about in food processing plants?
The main issue to deal with in terms of exterior contaminants is the environment where the plants are located. A lot of the time, these plants are located away from major cities. Agricultural challenges are common as many of the plants neighbor large agricultural fields. But inside, the process itself produces contaminants that vary greatly depending upon the food or beverage being produced.
Davidson says, “Think about a beef plant where you’re processing thousands of cattle a day. You can imagine the contaminants all the steps required to produce the steaks we love can create. Food plants have a tremendous amount of internally generated contaminants and because of that, require a great deal of water to keep areas clean.”
Davidson continues, “Moisture control is key in food and beverage plants, especially large processing plants. Most decent-sized food plants will have two processing shifts as well as a third shift, sometimes known as the ‘sanitation shift.’ Production is stopped and an entire shift is dedicated to cleaning and sanitation. There are some situations where much of the production equipment is disassembled in order to clean those hard-to-reach areas.”
There are many internally generated contaminants that can be caught in a machine. They get trapped underneath a surface or in gears or belts which results in continuous quality control measures. A case study of the Hi-flo-Es®, Durafil® air filter at a Midwest beef producer
What are the concerns for air filtration in food packaging plants?
Whatever is in the air when a product is sealed, it’s going to stay in the container. There is a saying that ‘Air is an ingredient in food.’ So from an air filtration point of view, there are some areas, and packaging is generally chief among them, that should be the cleanest areas.
One technique is to have clean, filtered air delivered to the area in greater volumes than surrounding areas. This creates a zone of positive pressure causing the air to cascade downward from the most sensitive areas to the least sensitive areas. Ideally, a food plant layout is designed so the most sensitive area has the highest air pressure and flows towards the least sensitive area. Plant engineers consider the processing steps when designing systems and buildings, and commonly install partitions to guide the air from the most sensitive area.
Air filtration happens first. Davidson illustrates the process, “Air is drawn through an air filter and is filtered to whatever level the facility requires. Inside the facility, it is positively pressurized relative to the outside and can be described as ‘working inside a balloon.’ Literally, you can open a door to the outside and have the door fly open because the pressure inside is greater than the pressure outside.”
Davidson believes this is a very desirable outcome, “That means there is more pressure inside. Imagine you’re a tiny passive pathogen germ or mold spore on the outside. You can’t get through that air pressure barrier. An actual barrier that you can’t get past. So that’s why you have positive pressure because it helps keep contaminants from getting inside.”
Why is high-efficiency air filtration important for food and beverage safety?
High-efficiency air filtration keeps organisms and just general dirt getting in the food. For food and beverage, either the taste or the safety of the products being processed can be compromised if there are airbourne particles that interact with and contaminate the products or get trapped in the packaging. It’s important to note, over time, some packaging degrades. We have all opened up a package of food and it smelled bad. Air may have leaked in and either carried pathogens in or the food itself contained oxygen-fed pathogens. Either way, food and beverage safety is dependent on air filtration.
What would be a typical pathogen to be concerned about in food processing plants?
It varies according to what is being produced. Typically E. coli is a major concern, along with listeria, campylobacter bacteria, and salmonella. Much depends upon the temperature of the food.
Chicken production and packaging have big issues with salmonella. Producers carefully inspect for it. If you think about all the different foods that you enjoy yourself, each one has a different method of production and packaging which means each one has different concerns to consider.
How does air filtration play a role in keeping pathogens at bay in food and beverage production and packaging?
Air filtration prevents carrier particles from entering food and beverage production facilities, and prevents them from landing on surfaces. The surfaces are called “food contact surfaces,” surfaces that come into contact with products during production, processing, and packaging.
Taking E. coli or any pathogen as an example, using the term germs, Davidson says, “The germs can’t necessarily move alone. They don’t have wings. They can’t fly. They can’t walk. And we say that about viruses too. They can be transferred by air by attaching to particles which are often referred to as carrier particles.”
Carrier particles can come in from the outdoor environment or livestock and produce themselves, and find their way inside food and beverage facilities. This affects the quality and safety of the products.
If there are dust particles in the air coming from a gravel road near the production facility, that gravel could carry harmful particles. Also, contaminated air can enter the plant itself or people and vehicles can bring particles into the facilities.
How are standards for air filtration in food and beverage production established and regulated?
Health Canada, like its counterparts in the U.S., the United States Department of Agriculture (USDA), and the Food and Drug Administration (FDA), does not directly regulate or approve intake air filters that protect the air within food and beverage production and distribution facilities. For example, lunch meat, chicken, milk, canned goods, frozen meals, and soft drinks; all have a different production process and all could have various air filtration needs. Federal regulators do not specify the actual MERV value of the air intake filters in each facility producing the food or beverage. It is essentially up to companies that run production facilities to determine the air filtration that delivers the level of air quality required to produce safe foods.
If, for instance, in yogurt, chicken breast, or beverage processing facilities, MERV 14 or higher filters are a common choice, which may include HEPA filters. It is what’s necessary to deliver the air quality needed. With very few exceptions, regulators don’t set those standards as they do in other industries. For example, in healthcare, there are code-enforcing agencies that rely on published standards such as FGI/ASHRAE 170 which offers guidance on the minimum filtration efficiency based on the space. Since these spaces are common to most hospitals, it is much easier to set standards. As mentioned, there are many different food production processes, making it very difficult to create a comprehensive standards document for the food and beverage industry.
Without air filtration standards, the onus is on plant personnel. Plants are required to produce safe food. Regulators can give guidelines and communicate best practices. Finally, producers must make sure that the air quality inside plants is safe or else they will not be in business for long. Food and beverage producers do a lot of science and try to figure out what it is that they need to keep out of their food and how to do so.
An air filtration solution provider should not say to a food facility, “you need a MERV 14” when consulting on air filtration. It is helpful for the air filtration expert to offer basic information from their experiences with similar facilities. The information can serve as a benchmark of what like facilities have found to be effective. Ultimately, the facility itself needs to do the research necessary to determine what contaminants need to be removed from the air in order to produce safe food. Based on the facility’s collected information, air filtration experts can then advise on the rated air filtration efficiency needed to deliver proper air quality for the environment.
Dealing with hazards in food and beverage production
Companies often appoint a committee of people responsible for identifying potential hazards to go through every single step of the process to identify critical points where there is high contamination potential. Procedures are then determined and implemented to keep products safe.
One experience comes to mind for Davidson, “At this one production line, there was a door opening regularly in an area next to a gravel parking lot. A study was done, and a system was installed to make sure the door closed when not in use. A partition was also constructed in the entranceway with a stand-alone air purifier to further protect that area. This is a case where an individual facility analyzed its processes and took the necessary filtration steps to produce safe food. The building design may not exist elsewhere, but it did in theirs and they corrected it to protect their food.”
In food production plants, are MERV-A rated air filters really necessary?
Yes, they are absolutely necessary, specifically in food production. For example, a food engineer determines an average of 75% of all airbourne particles need to be removed between 0.3 and 1.0 micron size because of the risk of carrying particular pathogens that could jeopardize food safety. According to the MERV value chart, a MERV 14 air filter will collect the 0.3 to 1.0 micron-sized particles. However, an electrostatically charged MERV 14 filter may drop to a MERV 11 within six months and capture only an average of 35% or less of the risky contaminants. If a study was done by the facility and they determined because a MERV 14 filter is rated to remove an average of 75% that’s the minimum MERV value required to protect that process, they would be out of compliance long before the filter was scheduled to be replaced. The degrading MERV performance is why it’s critical for food production managers to understand the difference between MERV and MERV-A-rated air filters. Food plants should not use an air filter that maintains its efficiency. An air filter that loses its efficiency is an air filter that jeopardizes food safety. Read more about MERV-A rated filters and how they are tested
Using an air filter with a lower MERV rating as a prefilter in a two-stage air filtration system is common and acceptable. However, the final filter should always be a MERV-A-rated air filter because it will maintain its minimum efficiency for as long as it’s in service. The bottom line is high-quality, MERV-A-rated air filters help protect food safely.
When should you use air cleaners and air purifiers in food production and packaging?
Food production can be a very messy process and can create a tremendous amount of internally generated contaminants. Rooftop air handling units clean the outside ambient air that enters the plant, but the processing inside needs to be considered. For example, imagine how messy it is when working with thousands of cattle and making T-bone steaks. In many cases, contamination is created on the spot.
In some cases, additional air filtration is needed. Davidson illustrates this by using the example of welding, “If you walk through a welding facility, they’ll of course, have rooftop units delivering filtered air inside, but there are also separate units above the welding area exhausting internally-generated gases and fumes that are unwanted production by-products.,. It’s the same with food. In some cases, there are additional air filtration devices nearby that could be either a portable unit that can be moved when production switches throughout the day or a fixed-in-place unit such as one hung from the ceiling over a particularly contaminant-high area. Equipment such as this adds an extra layer of air filtration in those areas where there are a lot of contaminants.”
One ceiling-mounted solution would be the CamCleaner Horizontal®, The unit can be strategically located to draw air up with a high level of contaminants such as grease for example. Grease can certainly affect food quality, but it’s also a safety hazard because the grease can drip and settle onto surfaces which can create problems.
In one case, Davidson states, “A major beverage plant used a CamCleaner Vertical® air filter, which is a large unit on wheels. The facility rolled the unit next to a particular processing line where peracetic acid (PAA) was being used as a disinfectant because fumes from the process were creating issues with the workers. The CamCleaner Vertical’s was equipped with molecular filters to remove the gaseous contaminants from the air. By using the air cleaner, the facility radically improved its process and protected the line workers. It would have been very difficult to solve this problem without the portable CamCleaner Vertical solution.”
How can you save time and labour costs with air filtration in food and beverage?
Maintenance workers have to be sent on roofs to change air filters regularly. This can happen as often as once a month. During winter months this means once a month for up to possibly five months per year, there’s a higher risk of injury and increased challenges due to the harsh conditions of snow, ice and cold. The reverse is true in areas with very high temperatures as rooftops get much hotter than the ground level surrounding the plant. The longer the air filter lasts, the fewer change-outs are required and the fewer risks need to be taken. The chance of workplace injury is reduced.
By doing fewer air filter changes, possible roof damage is less due to reduced people traffic on the roof. Damage to a roof can impact food safety as rainwater and melting snowfall through the leaks to the production floor below. The benefits of extending from a monthly change-out to a change-out every three months or from three months to six months can significantly impact a facility’s bottom-line. In some cases, it is possible to go from quarterly change-outs to only having to do a change-out once a year.
Change-outs can be scheduled in the fair weather parts of the year, like spring or fall, reducing trips to the roof in the cold of winter or dangerous heat of summer. Common feedback from the change to high-quality, long-lasting filters, is a sense of relief not having to constantly go on the roof during stretches of bad weather. Davidson says, “You can just imagine what it’s like, in some locations that I have visited, to have to change 50 air filters per month, every month. One location where I consulted required the crane rental because the air handling unit was three stories high which made ladders very unsafe. And the access doors to the roof from the inside meant you could only carry one box of filters to the roof at a time. By introducing high-quality air filters with a long service life, this was now a job that only had to happen once a year, sometimes once every 18 months. That saved this location a great deal of money and they improved their air quality as well. ”
Another major concern is air filters which exhibit a significant increase in pressure drop after a few weeks. If pressure drops too much it could result in a low-air alarm. If that happens, production shuts down until the situation is rectified. The lack of proper pressure could jeopardize food safety not to mention the downtime that leads to lost revenue for companies.
How to save energy at food and beverage plants
By including a lower-pressure drop air filter in a location with variable frequency drive (VFD) fans where the fans have been set to run at a consistent speed, facilities can actually slow the fan speed and save energy while still supplying the same amount of air. Davidson states, “But some plants would rather have the extra air created from an air filter with a lower average pressure drop, instead of saving energy. They continue to run the fans at whatever setting they had before because as one engineer said to me ‘air is gold.’” They can use the extra airflow to positively pressurize other areas of the building. This limits low-air alarms and shutdowns. Shutting down production costs them much more than energy.
One of the best things to do when planning air filtration is to engage with a consultant and determine what filtration solutions will achieve the facility’s needs. Air filtration experts know best practices and can use complex formulas and tools for all applications to help achieve designated goals and make the business operations safer. How to save energy with air filters
Talk to an air filtration expert to get the best advice on labour savings, extending air filter life, reducing the total cost of ownership, and choosing the right air filter for every application related to the food and beverage industry. To consult with an air filtration expert on any of the topics covered in this post or for further information, please use this contact form and an air filtration expert from Camfil will answer any questions you may have.
About Camfil Canada Clean Air Solutions
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Source: Air Filter Expert Mark Davidson
Camfil Canada Inc.