Food manufacturers, processors and packers are required to comply with an assortment of food safety standards and regulations. From microbiological hygiene to cross contamination and allergen control. Not only do these standards and regulations address the end food product themselves, but also the processes and facilities that are a part of the operation. Although they can sometimes appear as a hindrance, standards and regulations are essential for ensuring that food manufacturing and production operates within in a clean, safe and hygienic environment.
The whole food industry is centred around perishable products that can at some stage be effected negatively by bacteria. In the manufacturing and processing of food products there are plenty of opportunities for various airborne particles to be emitted to the indoor environment through the air handling system and duct work.
Sources of airborne contamination include:
- Raw materials
- Cooking and processing of food products
- Poorly designed, cleaned or maintained air handling systems
- Machinery, computers and equipment.
Airborne contamination control and removal of airborne bacteria should be considered in an overall plan to improve indoor air quality. The indoor air quality in a food manufacturing or food processing facility must meet certain requirements that are outlined in food hygiene audits and inspections.
Airborne Contamination Removal Methods
It is essential that a manufacturing facility provides adequate ventilation or control equipment to reduce odours and vapours in areas where they may contaminate the production process. This includes steam and VOC’s.
It is recommended that the positioning of air vents, fans and extraction units is effective for air hygiene management and the locations are determined to ensure that the potential for airborne contamination is minimised. Care also needs to be taken to ensure that the air is moving from high to low care areas or from low to higher dust loading areas.
Properly designed air handling systems control airborne particulates and odours, therefore minimising the risks to products from airborne contamination by infectious pathogens. Pathogens such as Salmonella and Listeria, toxigenic pathogens like Staphylococcus aureus and finally spoilage microorganisms such as yeast, moulds, Pseudomonas and lactic acid bacteria.
More Than Just Hygiene
Not only do air handling systems help to reduce the cross contamination caused by these airborne impurities, but they also important to ensure efficient air filtration and distribution. Effective air filtration and distribution helps to remove the heat imposed by the processes and people within a food factory. They also provide sufficient fresh air, prevent the ingress of airborne contamination and avoid regions of stagnant air.
Manufacturers can sometimes overlook the temperature within their production environments. Food manufacturing facilities that operate at temperatures below 13OC could be damaging their production. Evidence shows that it is prejudicial to food safety to ensure that the air distribution maintains a steady temperature above 13OC, unless there are specific outlined requirements. A clean and efficiently operating air handling system can ensure effective air mapping and have the ability to control temperatures across an entire facility.
A Breeding Ground for Bacteria
However, no matter how well a ventilation system works, grease and other extracted products will build up in the ducting and air handling units of an extraction system. As a result, dust and bacteria will accumulate in the air ducts and air handling systems. These contaminants are pulled into the HVAC system and re-circulated up to 10 times per day, on average. Over time, this re-circulation causes a build-up of contaminants in the duct work, these then become a breeding ground for bacteria and mould.
The build-up of dust, dirt and grease in air ducts can result in significant health & safety issues due to potential fire hazards and poor performance.
Reduced effectiveness of an extraction system, can impact on equipment service life. Furthermore, it has the potential for more serious problems later down the line.
The Importance of Cleaning
Air system hygiene is controlled by regular cleaning (and disinfection) to prevent the build-up of dust, product or condensate that may provide a focus for microbial growth. Without regular cleaning, air will pass through the polluted duct carrying bacteria onto or around the food process areas. Comprehensive duct work cleaning and cleanliness surveys also highlight the conditions of the ducting and help to manage any necessary repairs that could go unnoticed.
It’s Not My Job!
It is the duty of the building owner or facilities manager to ensure the maintenance and cleanliness of the duct work and air handling systems. They also need to be able to provide suitable maintenance and sanitation records to support audit compliance.
A Wealth of Benefits
As well as minimising airborne contamination and reducing health and safety risks, cleaning can yield significant long-term energy savings. When an HVAC system is not maintained and clean, it has to work harder. Research shows that dirty coils and blowers in commercial buildings can cut efficiency by as much as 40%. Consequently, when a system is running efficiently, less energy is used and that saves you money.
With lower potential for contamination, improved efficiency, and fewer health and safety risks, it is safe to say that there are a wealth of benefits that unfold from ensuring the cleanliness of your duct work and air handling systems.