This article explores the importance of effective Hygiene Monitoring within the fish, seafood, and fish processing industry. It also provides an in depth comparison of conventional ATP testing against the A3 system - an improved ATP methodology.

In the seafood, fish, and fish processing industry, it is impossible to overstate the importance of effective hygiene monitoring. After all, this sector deals with three of the 14 major allergens and faces the added concern of histamine toxicity.

Despite being a varied sector, with sites producing everything from raw sushi to canned tuna, the detection of organic material is an essential process across every site. This has led to an industry-wide examination of hygiene monitoring – a movement that has exposed the limitations of conventional ATP testing and resulted in many factories moving over to a more accurate and reliable approach: the A3 system.

With this in mind, we have created a guide to validating the cleanliness of your factory. In this article we will cover all of the areas listed below. There is helpful content in each section, but you can also use the links to skip to the subject most relevant to your site.


1. Is ATP testing a reliable approach to Hygiene Monitoring?

2. Is there a more reliable approach to Hygiene Monitoring?

3. How different are the results produced by conventional ATP tests and A3 technology?

4. Why is A3 technology especially suited to seafood and fish processing?

  • The dominant adenylates in seafood and fish
  • The relationship between ATP and salt
  • The nature of the food residues being tested
  • Handwashing in the fish processing industry
  • A3 and allergen testing
  • A3 and Histamine detection

5. How do I roll out the A3 system?

You can also follow the link below to watch a webinar on Hygiene Monitoring in High Care Environments. Hosted by Klipspringer Director Alex Carlyon, our in-house A3 specialist Radek Tameczka, and scientific advisor Dr. Stephan Speidel, this webinar explores the limitations of conventional hygiene monitoring methods and provides real-world examples of A3 verification at High Care production sites.

Is ATP testing a reliable approach to Hygiene Monitoring?

You will recognise ATP testing as a conventional approach to Hygiene Monitoring. It has existed as the preferred method for a number of years, due to the fact that ATP (adenosine triphosphate) is a molecule found in every living organism.

When ATP is detected, it generates a high reading for RLU (relative light units). If an ATP test shares a high RLU reading, this indicates a high level of organic residue and a breeding ground for bacteria.

Sites have typically used this reading to determine if a surface or piece of equipment is in need of further cleaning. They have also assumed that if the same surface or piece of equipment passes an ATP test and generates a low reading for RLU, this is evidence of an effective clean and the absence of any organic residue. Unfortunately, this is not the case.

ATP is an unstable molecule that degrades in certain processes – including heating, blanching, fermentation, processing, and cleaning. It degrades to ADP and AMP, becoming undetectable to ATP tests. Although it becomes undetectable, the organic residue is still there and needs to be dealt with by your operatives. After all, this residue is an excellent breeding ground for bacteria and this next generation of bacteria could include ATP.

Is there a more reliable approach to Hygiene Monitoring?

Unlike conventional ATP tests, A3 technology can detect adenosine molecules in all three forms: ATP, ADP, and AMP. Consequently, it is able to provide an accurate reading of how clean a surface is even after processes such as heating, blanching, and cleaning have taken place.

As mentioned above, ATP generates an RLU reading, with the amount of ATP on a surface measured in relation to the intensity of luminescence emitted during an ATP test. When ATP is in an unfavourable environment (exposed to heat, acids, alkalis, and enzymes), it tries to conserve energy by reducing the intensity of luminescence emitted. This is why ADP and AMP become undetectable to standard ATP tests.

In contrast, A3 technology introduces ATP recycling enzymes that allow for conversion between all three adenosine molecules. It introduces the PK Enzyme to convert ADP to ATP and the PPDK Enzyme to convert AMP to ATP. The introduction of these enzymes allows the A3 system to carry out a simultaneous measurement of ATP, ADP, and AMP.

What exactly is the A3 system?

The LUMITESTER A3 SMART System detects all organic residue and microorganisms on surfaces and in liquids. It combines measurements of ATP, ADP, and AMP to determine cleanliness – sharing accurate results in a matter of seconds.

The system includes a lightweight device that is auto-calibrated and allows you to set your own limits for pass/fail results. As with a conventional ATP test, you simply insert a swab into the meter to generate a reading, but unlike a conventional ATP test, this swab contains recycled enzymes that allow the A3 system to detect adenosine molecules in all three forms.

You can then store and access your data via the Lumitester App.

  • Highest visibility of organic residue
  • Includes ADP and AMP measurements to show you what you've been missing
  • Generates results in around ten seconds
  • All-in-one solution saves time and cost
  • Use the Bluetooth app to view and analyse the data you collect
  • Cloud storage allows you to access results at any time, from any location
  • Track overall inspection scores with graphs
  • Ongoing support from Klipspringer and a dedicated team of microbiologists

Working in conjunction with the A3 handheld device, the LuciPac A3 Swabs introduces enzymes that enable the simultaneous detection of all three forms of the adenosine molecule. The range includes: Surface Swabs, Pre-moistened Surface Swabs, and Water Swabs.

  • Highly sensitive A3 (ATP+ADP+AMP) detection
  • Surface swabs, Pre-moistened Surface Swabs, and Water Swabs available
  • Shelf life: 15 months after production date
  • Storage requirements: 2-8°C, do not freeze
  • AOAC Certified
  • No chemical residue left behind after sampling/smearing

How different are the results produced by conventional ATP tests and A3 technology?

The graphs below show the results of an A3 system in comparison to a conventional ATP test. As you can see, both systems are detecting canned tuna, along with raw oyster, shrimp, tuna, salmon, and sea bream.

Even though the devices are testing the same surface, the results differ dramatically. The A3 System provides high RLU readings across the board, whereas, the standard ATP tests pass every surface. This discrepancy demonstrates the importance of introducing the recycled enzymes mentioned above. Without them, the ATP swabs indicate there is hardly any ATP present and suggest the surface is in no further need of cleaning.

In contrast, the A3 system uses the PK and PPDK Enzymes to convert ADP and AMP to ATP, generating a much higher and much more accurate reading.

If your site handles fish, seafood, or any other organic material, there is every chance that your ATP tests are currently passing surfaces that require further cleaning – unable to detect the AMP and ADP molecules that are still present on the equipment. Even the most dedicated Hygiene Team will struggle to validate their cleans if they are working with inaccurate information.

The video below offers a demonstration of the key differences between a conventional ATP test and A3 technology:

Why is A3 technology especially suited to seafood and fish processing?

The dominant adenylates in seafood and fish

The degradation of ATP-related compounds is more-or-less predictable after death. ATP also degrades to ADP and AMP when exposed to heat, acids, alkalis, and enzymes.  Across all species, raw fish contains high amounts of ADP. It is also worth noting that shellfish, including shrimp, oysters, scallops, and abalone, contain large amounts of AMP. This is also true of dried and canned fish.

Consequently, seafood and fish processing sites need to ensure their Hygiene Monitoring is capable of detecting adenosine molecules in all three forms.

Otherwise, to use the example of raw fish, a surface or piece of equipment could still be contaminated, but because a conventional ATP test is unable to detect ADP, it will generate a pass result and leave your Hygiene Team with a false sense of confidence.

In a peer-reviewed article published by the Kikkoman Biochemifa Company in 2020, the swabbing efficiency of an A3 system was tested against three standard ATP tests. Measurements were repeated three times and were carried out across a 10cm x 10cm stainless steel surface.

When testing raw chicken, which just like raw fish, sees ATP quickly degrade to ADP, the A3 test result was 15,872 RLU. In comparison, the results of the three ATP tests sat within the range of 20 to 173 RLU.

When testing beer, which just like shellfish, along with dried and canned fish, sees ATP quickly degrade to AMP, the A3 test result was 10,777. In comparison, the results of the three ATP tests sat withing the range of 0 to 200 RLU.

Even when detecting yoghurt, which has high levels of ATP, the A3 system still came out as the more sensitive test.

In May 2018, Volume 81, Issue 5 of the Journal of Food Protection published data relating to another series of comparative tests. As you can see, these results highlight the difference between a conventional ATP test and the more accurate A3 technology when applied to fish and seafood.

The relationship between ATP and salt

Many fish processing sites have dedicated salting areas, with large amounts of salt covering equipment and machines. Although the cleaning and sanitisation process will remove visual signs of this residue, any remaining sodium chloride could result in false negative readings from conventional ATP tests. In fact, a recent study at a number of salt-curing cod factories suggests ATP readings in salted areas may be significantly underreported.

So, why does this happen?

Standard ATP tests often display a reading of 0 after swabbing, with operatives making the understandable assumption that a reading of 0 always means a surface is clean. However, a reading of 0 can also mean a swab is faulty, has been exposed to high concentration of chemical detergent, has been used incorrectly, or contains a faulty enzyme. In the case of seafood and fish processing sites, a reading of 0 could also mean the swab has been compromised by salt/sodium chloride.

A3 technology is also impacted by a high salt concentration. However, unlike conventional ATP tests, the A3 system always produces a reading (normally between 1-8), even if it is extremely low. It will only produce a reading of 0 if it is alerting your operatives to a potential fault that requires further investigation. In the case of seafood and fish processing sites, a reading of 0 will inform your team of the possibility that the test has been compromised by high levels of salt/sodium chloride.

The nature of the food residues being tested

A report from The Norwegian Institute of Food, Fishery and Aquaculture Research revealed that output from conventional ATP testing is impacted by the nature of the food residues being detected. When applying the same critical limit to an entire fish processing plant, standard ATP tests indicated that hygiene levels in the slaughter house were considerably worse than hygiene levels in the filleting department. However, bacterial results revealed very little difference between the two zones. The reason behind this discrepancy is uncertain, but one possible explanation is the presence of blood in the slaughter house – a substance that typically gives high readings of ATP. In comparison, other soils such as muscle and fat were present in the filleting department – substances that typically result in lower ATP bioluminescence.

These findings suggest conventional ATP tests will generate different results depending on the organic residue detected. This is supported by the fact that ATP tests didn’t detect a high RLU reading in raw fish, but once the fish had undergone a heat treatment, a much higher RLU reading was recorded.

As previously mentioned, heat processes typically degrade ATP, so the ATP levels couldn’t have increased between the first and second round of testing. Instead, it is more likely that the standard ATP tests underestimated the levels of ATP because they were exposed to the fat-rich, raw fish. They were only able to detect the ATP molecules once the nature of the food residue had changed.

Handwashing in the fish processing industry

Handwashing checks are especially important when it comes to seafood and fish processing, with many sites favouring clean, bare hands over food contact approved gloves. This is another area where A3 technology can be put to use, as this system can identify operatives who are not ready to touch a production line. In the long term, it can also help sites to establish the best approach to handwashing – assessing the time, technique, and cleaning products.

An educational resource published by the Kikkoman Biochemifa Company shared a Case Study of a sushi store and plant. The organisation had the target of “firmly implementing handwashing” and needed a method that allowed them to find out if their efforts had been successful.

With the A3 system capable of providing results in around 10 seconds, the site was able to carry out on-the-spot checks, sharing immediate improvement guidance with operatives who failed the tests.

In comparison, the site’s previous method (using bacteriological screening with a culture test) took several days to generate results. this meant unclean hands were working on an active production line for days at a time.

A3 technology and allergen testing

In the UK, there are 14 major allergens that legally need to be listed on a label or provided information. This list features: fish, molluscs, and crustaceans.

Although the A3 system does not test for specific allergens and should not be relied upon for this, it can support you with the process of detecting allergens and potentially reduce your allergen swabbing requirements. This is because if a surface is free from organic residue, it follows that there isn’t any residue left to contaminate a non-allergen product. Essentially, the more accurate your hygiene monitoring, the more likely it is that your allergen tests will go smoothly. This is something the Klipspringer team can help you to validate.

Here at Klipspringer, we recently published a Case Study with McCain Foods. This study explores the impact of the A3 system on McCain’s Scarborough site. One of the key takeaways from the study is that during a six-to-eight-month trial, the Scarborough site found that if a surface passed an A3 test it would go on to pass a gluten swab and then an ELISA test. During this period, McCain Foods didn’t have a single allergen fail following an A3 swab pass.

On the subject of allergen control, it is also worth noting that we have launched a new range of Rapid Allergen Test Kits for: Egg (Ovalbumin), Casein, Gluten, Soya, Peanut, Crustacean, and Buckwheat.

These Lateral Flow Tests offer the following benefits:

  • Minimum accuracy rate of 0.5ppm
  • Simple, two-step process (eliminates Extraction Buffer Solution)
  • Assay time of 10 minutes
  • Stored at 2-30°C (no need for fridge)
  • Lifespan of 12 months

A3 technology and Histamine detection

In order to establish a complete picture of hygiene monitoring, it’s important that A3 technology operates alongside allergen and histamine testing. High levels of histamine can cause scombroid poisoning in humans, with symptoms including nausea, vomiting, hypotension, and heart palpitations. Good quality fish will typically have histamine levels below 10ppm, but depending on the species of fish and the country it is being processed in, histamine levels will usually sit between 50 and 200pm.

So what is histamine?

After a fish is harvested, the bacterial growth results in a increase of histidine decarboxylase. This enzyme decarboxylates (a chemical reaction where a carboxyl group is removed and carbon dioxide is released) the amino acid L-histidine. This results in the production of a heterocyclic primary amine: histamine.

If you have any questions relating to your Histamine requirements or would like to source testing swabs for your site, you are welcome to contact us on 01473 461800 or  

How do I roll out the A3 system?

The first thing to note is that you won’t have to navigate this process alone. Here at Klipspringer, we provide ongoing support for the implementation of A3 technology. Working closely with a team of micro-biologists, we will help you to establish benchmarks, create validation documents to share with your auditors, and train up your operatives.

We will also help you to get set up on the Lumitester App. Capable of data analysis, the Lumitester App can be used to store the data gathered through your A3 testing – automatically turning inspection pass rates into graphs, and recording every test alongside the date it took place and the operative responsible. Once you have this data, there is the option of downloading it onto Microsoft Excel. Alternatively, if you would like to access the data at any time from anywhere in the world, you also have the option of storing it in the cloud.


  • Upload results to the cloud via Bluetooth and PC connection
  • Set test points and benchmark values
  • Display time-series data for each test
  • Track overall inspection scores, with graphs
  • Access results 24/7 – from any device, anywhere.

So that brings us to the end of our guide to Hygiene Monitoring within the seafood, fish, and fish processing industry. We hope this article has highlighted the importance of accurate hygiene monitoring within this sector and has outlined the risks associated with conventional ATP tests.

If you would like any further guidance, the Klipspringer team would be happy to help with your enquiries. Our in-house A3 expert Radek Tameczka will also be available to provide support and relevant resources. You can contact us on 01473 461800 or Alternatively, you can use the form below to arrange a consultation

If you would like further guidance relating to Hygiene Monitoring, the Klipspringer team would be happy to help. Share your details below to arrange a free consultation.