The Building Engineering Services Association (BESA) TR19 regulations set out best practice for cleaning ventilation ductwork and kitchen extract flues. TR19 was developed in 1988, in order to “provide a safe working environment for staff; reduce fire risks; and avoid contamination of food preparation areas”. It has become the standard to adhere to when performing ductwork cleaning operations.
TR19 guidelines lays out best practice with regard to access to ductwork, inspection of ductwork, cleaning processes and post-cleaning checks.
The guidelines state that the system must contain enough access panels of sufficient size to enable regular inspection and cleaning.
The panels should be made of the same material as the ductwork and should include insulation, seals (to prevent leaks) and quick-release catches.
The recommendation is that panels are located at the top or along the side of the ductwork. Panels that have to be fitted on the underside but be sealed properly to ensure they don’t leak.
Inspection of ductwork must be carried out at regular intervals to establish whether it needs cleaning. The Wet Film Thickness Test (WFTT) assesses the level of build-up of grease and soft deposits and the Deposit Thickness Test (DTT) will gauge the extent of build-up of carbonised deposits. Inspections must be carried out at least every 12 months, with more frequent inspections to give a more accurate assessment of the required cleaning frequency. TR19 details the locations in the ductwork where the measurements of deposits should be taken. One state-of-the-art inspection method is by means of a camera probe. This allows engineers to see deep into the ductwork to confirm both the extent of the build-up and the type of cleaning process required.
TR19 outlines a number of cleaning methods, including hand wiping, hand scraping, chemicals, high pressure water wash, steam cleaning, rotary brush etc. Not all methods are appropriate for every type of ductwork and location.
The TR19 guidelines state the recommended intervals between cleans. The cleaning intervals for kitchen extract flues are dependent on the cooking methods used and the volume of airborne grease contaminants.
As grease in kitchen extraction systems is a well-known fire hazard, a new specification (TR19 Grease) was published in July 2019. TR19 Grease was developed to increase the level of compliance with regard to fire safety cleaning.
Although cleaning frequency is established by regular inspections, the minimum cleaning frequency recommendation is as follows:
Post Cleaning Verification
A visual inspection of ductwork and flues is carried out after cleaning. Deposits must not exceed .05 mm in thickness. A Post Cleaning Verification Report must then be provided detailing the systems that have been cleaned, photographic records, COSHH data on any chemicals used, observations on the condition of the ductwork etc.
HVDS engineers clean metal and fabric ducting and kitchen extraction flues to TR19 standards. They are also BESA Air Hygiene Operative (AHO) accredited. The course assesses their competency in working safely, the principles of ventilation ductwork, preparing the work location, cleaning ductwork systems, working sustainably and communication and behaviour in the workplace.
Maintaining good indoor air quality on site is essential. It optimizes contamination control, ensures audit compliance, improves the shelf life of your products and contributes to a safe working environment for your employees.
Without proper controls in place, air can be a source of contamination. It can act as a transport medium, moving contaminants from one area to another. These contaminants can include fungal spores, coarse dust and pollen (PM10 – where the concentration of particles that are less than or equal to 10 µm in diameter), fine dust and microorganisms like yeast (PM2.5) and microorganisms like viruses and bacteria (PM1).
There are typically three filter stages needed to adequately filter our contaminants in food production areas. However, there is no one size fits all and only a thorough risk analysis of the individual area can determine the correct specification for each filter stage.
Find out more about air filter classifications here.
High risk or cleanroom production areas will need to meet the highest standards of food safety. Filters for these areas should be capable of filtering out the smallest microbes, will need to be suitable for operation up to 100% relative humidity and be resistant to mechanical stress. In addition, filters should meet the ISO16890 standards and higher pre-filtration grades should be installed. Air management should take into account optimum room pressurisation and number of air changes. Furthermore, air movement, temperature and humidity should be monitored carefully.
In addition to choosing the correct filter grades, your filters should be changed regularly and to a set schedule and your air handling system should be cleaned on a similar basis. Cleaning should include the sides, wall and floor of the air handling unit (AHU), metal/fabric ducting, fan, cooling coil, heater battery, motor etc. These are all components which can harbour contaminants.
HVDS provides a risk assessment template, which helps you evaluate your air handling requirements for good Indoor Air Quality on site. Devised by our Indoor Air Quality experts, the template is a checklist to help you prioritise your actions to achieve BRCGS Food Safety Issue 8 audit compliance. Find out more here.
For information and advice on any of the above, please get in touch on 01785 256976 or contact us here.
Hygiene and Facilities Managers have long understood the benefits of keeping their air handling units and ductwork clean, but the Building Engineering Services Association (BESA) has now said that air cleaning and associated hygiene regimes should become standard practice after the COVID-19 pandemic.
The World Health Organization (WHO) tells us that smaller particles (less than 5 micrometers (µm)) will remain in the air for many minutes or even hours. In a BESA webinar last week, speaker Richard Greenwood of Radic8, said that the ventilation industry has “a crucial role to play both during and after the pandemic”. He explained that 40,000 virus-laden droplets can be released from a single sneeze and these can not only travel more than 8 metres, but can remain airborne for up to 3 hours.
During the BESA webinar, Mr Greenwood also said that there are 4 known transmission routes for COVID-19: direct contact, indirect contact, droplets and airborne. He stressed that preventing transmission at airborne level will stop build-up on surfaces and that will, in turn, reduce contact transmission.
As information continues to emerge about how coronavirus spreads around a building, experts agree it is essential to implement measures to tackle airborne contaminants. It is widely acknowledged that filtration plays an important role in tackling airborne contaminants but now more than ever, this should be supplemented with frequent and regular cleaning. According to Mr Greenwood,
“We now have evidence that microbial contaminants will grow on filters in 14 days and these either need to be tackled by more regular filter changes or by increased cleaning.”
David Frise, BESA chief executive, said the evidence presented by Mr Greenwood demonstrated the significant role the ventilation hygiene industry would play from now on in making buildings safe. Read the full article on the BESA website here.
HVDS offers a comprehensive hygiene service for your HVAC and LEV systems. Our customers benefit from regular and scheduled filter changes and cleaning and remedial work. For more information, get in touch on 01785 256976 or contact us here.
In February, we attended Food Safety Europe 2020 in London. Our Food Industry Air Filtration and Ventilation Consultant, Tony Carvell, gave a talk about the benefits of a holistic approach to managed indoor air quality and dispelled a few myths about maintaining clean air on food production sites.
Well worth a watch!
For more information about this topic click here.
Following Tony’s holistic approach talk, we had a lot of enquiries about our Risk Assessment Template. For your copy of our Risk Assessment Template for your food production site, please get in touch here or contact us on 01785 256976. Our Risk Assessment Template lists all those areas of your HVAC system you should be checking and maintaining to help you conform to the BRCGS Food Safety Issue 8. It will highlight any areas that need to be addressed, helping you to take control of your air handling system and maintain audit compliance.
Having dealt with customers the length and breadth of the UK and Ireland, we have found there are many myths and misconceptions when it comes to maintaining Indoor Air Quality (IAQ) on site.
As food safety is of paramount importance, reducing spores, microbes, dust and other sources of airborne contamination should be part of an ongoing air handling programme for food production plants.
Do you know how many people in the world fall ill after eating contaminated food?
According to the World Health Organization in June this year, an estimated 600 million people (that’s almost 1 in 10 of us) fall ill after eating contaminated food and 420,000 die every year.
In this article, we dispel some of the myths surrounding IAQ, and put you on the right track to help keep your air clean and audit compliant at all times.
Myth 1: ‘Outdoor Air Quality Affects Food Production’
Outdoor air quality has only a very minimal effect on contamination in the food production process.
One of our customers is located in the countryside in a low pollution area. The Engineering Manager has always been under the impression that the air on site was clean. He started to notice staining on the underside of his fabric ducting, however, and called us in to take a look. The air socks were in a high care area and, on investigation, we found mould growing inside them.
During winter his air supply system had been on heat mode and warm air coupled with moisture from production had created the perfect conditions for mould growth. This air in his system wasn’t coming from outside but was being recirculated through the system and air full of mould spores and bacteria was being carried to the high care production areas and risking food safety.
So rather than outdoor air quality, it’s Indoor Air Quality we need to be concerned about. In indoor environments, uncontrolled factors, such as processes and personnel, contribute to the release of microorganisms in the air, which result in the majority of contaminants found in production areas.
So, the threat to human health and the damage to the reputation and finances of a brand is real. These are the hazards of poor air management.
Myth 2: ‘We Have An Air Handling Unit So Our Air Must Be Clean’
Unfortunately, having air handling units on your site does not guarantee clean air.
We find that sites assume that having an air handling unit guarantees that any nasties in the air are filtered out. But if you have had no professional risk assessment carried out, there might be important aspects of your system that you are overlooking. For example:
- Is the filter grade adequate for the type of production taking place in your production area?
- Are the filters being changed regularly enough and to a regular schedule?
- Is there contamination in your ductwork?
Myth 3: ‘We Should Change Our Air Filters Once They Have Reached The End Of Their Useful Life’
The third myth is that you should change your air filters once they have reached the end of their useful life.
Some companies insist there is an optimal time to replace air filters from an energy/ efficiency point of view and rely on pressure drop readings to indicate when this should be. We often find that our customers’ in-house engineers are often too busy to check pressure drop or examine the filters for wear and tear/build up and so it is not picked up soon enough that they need changing.
At HVDS, we know from experience that it is better to be preventative and change them according to a set schedule, and retailers will often state what this schedule should be. Changing air filters to a set schedule means that virus and bacteria do not get chance to build up.
This brings us to Myth 4.
Myth 4: ‘We’ve Changed Our Air Filters So Our Air Quality Is Good’
People think that just because they have changed their air filters, their IAQ must be good. Air filters, however, are only one of the potential sources of contamination when it comes to your HVAC system. In fact, some of the most common sources are often overlooked.
How about your ductwork? Looks great on the outside, but how often do you check inside? As well as mould growth in ductwork, we also see substances such as grease, packaging dust and grain and cereal dust.
A full Risk Assessment will often reveal further areas of concern, for example:
- The aluminium in coils in the AHU can break down, over time, to a fine powder residue, which could get carried through the HVAC system and into food.
- Condensate can pool in the drains, presenting a risk of Listeria and Legionella.
- Debris can build up in fans, leading to the growth of bacteria, which could get into food.
Myth 5: ‘We Can Base Indoor Air Management On Stats From Tests’
The final myth busted is that we can base indoor air management on stats from tests. This is simply not true. Each and every plant we visit is different, manufacturing different products with different processes, and therefore each has a different set of operating conditions. It depends very much on what you are manufacturing or processing as to what your air handling requirements will be.
Since tests done in labs can’t possibly reflect real operating conditions, there is no ‘one size fits all’ when it comes to air management. For this reason, we provide a comprehensive Risk Assessment, based on a Risk Assessment Template that conforms to the BRCGS Food Safety Issue 8. Our Risk Assessment will highlight any areas that need to be addressed, helping you to take control of your air handling system and maintain audit compliance. To enquire about our Risk Assessment Template, please contact us on 01785 256976 or get in touch here.
You could be forgiven for thinking that your ductwork is as clean as a whistle. After all, it looks it from the outside, doesn’t it? But HVDS engineers, who have helped customers the length and breadth of the country, know that external appearance can be deceptive. Our Hygiene Team have removed a variety of substances from air handling system ductwork as part of their cleaning and maintenance service, thus improving the efficiency of the system, reducing the energy usage of the production area and optimising food safety and the health and safety of employees.
It obviously depends on what you are producing as to what lurks inside your ductwork. A recent visit to a baked goods factory revealed a build-up of mould and bacteria inside their fabric ducting. HVDS engineers removed the air socks and rather than launder them, the socks were condemned, and replacement socks were installed in the relevant production areas. The engineers also removed any debris and sanitised all other relevant parts of the Air Handling Unit to ensure maximum hygiene. All this was achieved for the factory just ahead of a major audit. Read the case study here.
At a morning food manufacturing site, a steel duct had burst under the pressure of a build-up of dust inside it. HVDS Technical Engineers arrived on site within 24 hours. When we investigated further, we found that the ductwork across the whole system was clogged with dust from production, resulting in a serious reduction in machine efficiency. Our engineers stripped down the machinery and carried out a massive clean-up exercise. It is worth noting that dust from the ductwork explosion had been dispersed across four floors of the production facility, causing a major food safety and cross-contamination hazard. Some food dusts are flammable under certain circumstances, and a resulting fire could have much worse consequences. Read the case study here.
Grease in flue extract systems can be a problem if not cleaned regularly. The photo below shows build-up in the ductwork at one UK food manufacturing site. In places the extracted product reached a depth of 3 inches or more. The grease & carbon was removed using scrapers, brushes and vacuums. In total, around 10 gallons of fluid grease and foreign matter was removed from the ductwork and extraction flue system over a period of 5 days. Read the case study here.
Our BESA qualified engineers work in accordance with industry standards, using cutting edge techniques, such as mechanical cleaning, rotary brushing, compressed air jetting and traditional hand cleaning. Internal ductwork inspections can be carried out via camera probe.
For more information about our HVAC and LEV hygiene and maintenance service, take a look here or download our brochure here. To contact us for advice or to book your visit from our Hygiene Team, please get in touch here.