Guide to ATP monitoring

ATP monitoring is a quick, simple-to-use testing method for assessing the cleanliness of surfaces in food processing facilities. Food and beverage facilities are using ATP monitoring to validate that there is no presence of ATP. If there is a presence of ATP on a surface, it indicates it hasn’t been cleaned properly. An unclean surface has the potential to harbour bacterial growth. The surface should be re-cleaned and re-tested with a luminometer.

What is ATP?

Adenosine Triphosphate (ATP) is present in all micro-organisms, plant and animal cells and is the molecule that provides energy for cellular metabolism. ATP provides a marker or indicator of contamination from a biological source. ATP is the universal unit of energy used in all living cells. Luminometers and ATP swabs use bioluminescence as an indicator to detect the presence of ATP on surfaces.

Luciferase enzyme- naturally occurring in fireflies

What is bioluminescence? 

Bioluminescence is the result of a biochemical reaction where a substrate mixes with oxygen and ATP (this is controlled by the enzyme). This chemical reaction excites a specific molecule which is a combination of Luciferin and Luciferase. This results in a decay that produces light. The unit of measure used in bioluminescence is RLU.

What is an RLU?

An RLU or a Relative Light Unit measures the light produced by the chemical reaction, bioluminescence. When a hygiene swab test is activated, this chemical reaction generates a light output. Luminometers quantify this light with an RLU output. RLU measurements will vary between manufacturer systems because they use different sensor technologies.

What remains the same is, the more ATP present, the more light is present. The higher the RLU reading on your luminometer, the higher the amount of ATP is present. Comparing RLU measurements of two systems is like comparing Fahrenheit and Celsius. Both are two different scales but for the same temperature result.

Luminometers come preset with generic RLU limits which can usually apply to most processing facilities. You must do an initial review to confirm these limits are acceptable to your facility. Perform a simple plot of the RLU overtime with a review to exclude any obvious outliers e.g. high RLU values. Your review should use a scale that includes the results expected from an unclean surface. If your results are erratic, it indicates your cleaning process should be investigated and stabilised.

At Gem Scientific, we have a team of hygiene specialists which are on hand to answer any of your questions. Our staff have been trained in our hygiene monitoring products including luminometers, swabs and software.

We can offer you free training with one of our specialists if you require a face-to-face tutorial. To enquire today: Livechat, 01924 444577 or

Our ATP systems

Hygiena™ EnSURE™ Touch Luminometer

The Hygiena™ EnSURE Touch Luminometer provides rapid and accurate hygiene verification to support your HACCP program.
Learn about the EnSURE Touch.

The 3M™ Clean-Trace™ LM1 Hygiene Monitoring and Management System helps you achieve the highest levels of product quality, safety and environmental hygiene.
View the benefits and features of the 3M™ Clean-Trace™ LM1 Hygiene Monitoring and Management System

The Hygiena™ SystemSURE Plus™ meets the demands of the smallest and largest companies around the world. Its increased memory enables users to store up to 250 locations in one group.
View the benefits & features of the Hygiena™ SystemSURE Plus™

For more information about anything mentioned in this blog, contact our hygiene specialists on 01924 444577 or

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