What is ATP?
ATP (adenosine triphosphate, is an organic molecule that is used by living cells as their main source of energy. Animal, plant, bacterial, yeast, and mold cells produce and break down ATP in order to drive a number of biological processes including muscle contraction, photosynthesis and the creation of different proteins.
Why use ATP as an indicator of effective cleaning?
ATP is naturally present in all organic material. Therefore, most foods will contain some level of naturally occurring ATP. The SystemSURE Plus luminometer combined with Ultrasnap(TM) ATP swab use bioluminescence to detect residual ATP as an indicator of surface cleanliness. The presence of ATP on a surface indicates that the surface has not been adequately cleaned and that has the potential to harbor and support bacterial growth. The residue may also contain hazardous material including potential allergens.
Do all foods contain ATP?
Most foods will contain some naturally occurring ATP. However, the act of processing or cooking can decrease the levels of ATP.
Can I compare RLU counts to CFU plate counts?
The SystemSURE Plus luminometer will detect total ATP present on a surface. It does not differentiate between the ATP stemming from microbial cells and the ATP from any other residue left on the surface due to inadequate cleaning and sanitation procedures. Therefore, you cannot directly compare the RLU count from the SystemSURE Plus to any standard plate count results. However there is a very strong correlation between ATP and microbial cells. The presence of ATP on the surface indicates that it has not been adequately cleaned. The primary purpose of cleaning is to remove product residue for product contact surfaces. Effective cleaning simultaneously removes the material capable of supporting microbial survival and growth, as well as many of the microbes themselves. Studies have shown about an 80% correlation.
What is biofilm?
Biofilm is a population of microorganisms attached to a solid surface. Biofilm population can include bacteria, fungi, yeasts, protozoa, and other microorganisms. Biofilm forms when bacteria attach to surfaces exposed to water, and begin to excrete a slick, glue-like substance. Biofilms can be held responsible for the loss of billions of dollars in productivity in both product and equipment damages. In a food processing facility the presence of biofilm can lead to poor product quality and/or lost product due to contamination from the biofilm.
What if you have Biofilm?
Ultrasnap ATP swabs have a sanitization agent on the swab tip that cuts through a biofilm and exposes the underlying cells. If a biofilm has developed, it will most likely trigger an elevated RLU count.
How does the SystemSURE Plus work?
The SystemSURE Plus system detects ATP using a chemical reaction. A sample is collected using a Ultrasnap ATP swab. Ultrasnap ATP swabs are moistened with a buffer that aids in the removal of any biological material (ATP) on either a wet or dry surface. The swab also contains an agent that will break through a biofilm and expose the underlying cells, if one is present. Once the sample is collected, it is exposed to an agent that will release the ATP contained inside any of the collected cells. The ATP released from inside those cells, along with any free ATP picked up from the equipment surface by the swab, is then available to react with Utlrasnap's unique liquid-stable reagent. Ultrasnap's unique liquid reagent is made from two firefly enzymes called luciferin and luciferase. These are the same enzymes found naturally in the firefly. When the luciferin and luciferase enzymes are exposed to ATP, light is produced. This light is then detected and measured by the SystemSURE Plus.The amount of light detected is directly proportional to the quantity of ATP, and accordingly, is proportional to the amount of residue on the equipment surface. The higher the count, the more ATP detected the more residue on the surface.
What does the number mean?
The SystemSURE Plus luminometer displays results in RLU (Relative Light Unit) values. The light produced from the ATP reaction in the Ultrasnap swab is emitted in the form of photons. Photons are tiny bundles of energy and are the basic unit of light. The SystemSURE Plus detects these photons and displays them directly as RLU values. Therefore, the more photons (light) that is detected by the SystemSURE Plus, the greater the RLU value. The linear scale allows for easy comparison between clean and unclean surfaces.
The SystemSURE Plus luminometer detects total ATP, not just ATP from bacteria, yeast, and mold but also the ATP from any food residue on the processing equipment surface. Therefore, an RLU value is not the same as a microbial colony forming unit (CFU). Since the SystemSURE Plus luminometer is detecting total ATP, it is unknown whether the RLU result displayed by the SystemSURE Plus is due to the detection of microbial ATP, residual ATP, or a combination of both. Therefore, a comparison cannot be drawn between ATP/RLU values and standard plate counts. However microorganisms cannot live without food residue and will be killed by sanitizers if no food residue exists, therefore by having no or very low levels of ATP on a surface you are taking away the food supply of microorganisms and allowing your sanitizer to work correctly.
What areas should be swabbed?
Food contact areas and hard to clean areas should be the main focus of your swabbing program. Food contact areas include both direct and indirect food contact surfaces. Direct contact areas will be those surfaces where if there is any contaminate present it will contaminate the product. No further microbial killing steps, such as pasteurization or cooking, will be encountered after contact with these surfaces. Indirect contact areas are those from which condensate splashed product, dust, or liquid has the potential to be dropped, drained, or drawn into the product. A few examples of hard to clean areas may include filler heads, O-rings, nozzles, and areas with irregularly shaped surfaces, corners, grooves and cracks.
What is the proper swabbing technique?
Swab an area that is 4 inches by 4 inches square. Hold the swab at a 30 degree angle to the surface. Apply pressure to the swab tip and be sure to continuously roll the swab so that the entire swab tip comes in contact with thee surface. If the surface you are swabbing does not have an area that is 4 inches by 4 inches, such as a O-ring, than swab as much of the surface as possible. To prevent contamination of the swab, avoid touching the swab tip with your hand or anything else except the surface that is being swabbed. Once the swab has been activated, it should be read in the SystemSURE Plus within 60 seconds.
How should the swabs be stored?
Swabs should be stored in the refrigerator at 0-7 degrees Celsius. The expiration date will be 12 months when stored properly. Ultrasnaps and Snapshots are valid for 1 week at room temperature.
Does the surface have to be dry before you swab?
No, the surface does not have to be dry in order to obtain valid swab results. The surface can be either wet or dry. The swab tip is pre-moistened with a buffer to facilitate removing any ATP from a dry surface.
How often should critical and regular test sites be swabbed?
Critical test sites should be swabbed on a daily basis or anytime prior to start-up. If a failure is generated immediate corrective action should be taken and the area re-swabbed until a passing result can be obtained. Corrective action steps may include and additional water rinsing of the entire area or a complete re-cleaning if necessary.
How many locations and data points does the SystemSURE Plus have?
The SystemSURE Plus luminometer has 99 location points and can store a total of 500 data points before the information needs to be transferred to a PC. Location points are labeled numerically, but are associated to a label on the data software. For example: PROG: 1 = Machine A O-Ring 1 in your data analysis software. When you transfer the data from the SystemSURE Plus to the PC all the data is associated to the right label.
What limits do you recommend and how do I determine my limits?
Guideline for Threshold Setting
Pass Caution Fail
11 - 29
These threshold settings have been determined based on plate counts on different instruments, surfaces and daily uses. Hygiena recommends that you determine your own threshold settings by doing plate counts in conjunction with ATP swabbing or by using one of the two "Recommended Practices" provided below.
When using the threshold setting provided by Hygiena for the SystemSURE Plus, readings less than 10 RLUs indicates that the surface is considered clean. Readings between 11 - 29 RLUs indicates a warning that the surface is not adequately clean. If the reading is greater than 30 RLUs, the surface is considered dirty.
If you are not following these guidelines and have established your own company guidelines then we recommend you follow the following two practices:
1. Identify control points and critical control points.
2. Clean product surfaces.
3. Conduct ATP Hygiene Monitoring tests at several locations and over several days to give 20-50 results. Calculate the average and standard deviation (s.d) for the RLU values.
4. Set limits as:
Pass = £ Mean RLU
Caution = > Mean RLU < Mean + 3 (s.d)
Fail = > Mean RLU + 3 (s.d)
Pass 0 - 10 RLU
Caution 11 - 29 RLU
Fail > 30 RLU
5. Monitor results and assess trends. Recalculation regularly to optimise limits and improve standards.
1. Identify control points and critical control points.
2. Clean product surfaces thoroughly, even 2 or more times to achieve the best possible level of cleanliness.
3. Conduct ATP Hygiene Monitoring tests at each location, using 5-10 test replicates.
4. Calculate the average RLU which is considered to be the pass level.
5. Fail limits are determined by multiplying the Pass level by 2 or 3 fold.
6. Caution is the region between Pass - Fail limits.
Do I have to recalculate Pass/Fail thresholds when using snap shot?
No. snapshot(TM) ATP swabs have been designed to put off the exact same amount of light per ATP molecule as the swab designed for the luminometer you are using.
Should swabbing be completed before or after the application of sanitizer?
Swabbing should be done before the application of the sanitizer. The surface should be completely clean before the sanitizer is even applied. This allows for a true reading of whether the equipment surface has been properly and effectively cleaned. However, if this is not an option due to clean-in-place (CIP) systems or for any other reason, it is perfectly acceptable to swab after the application of sanitizer. You should wait for the sanitizer to evaporate before swabbing.
Will sanitizers interfere with my swab counts?
Sanitizers when diluted and used in concentrations recommended by the manufacturer, will not cause interference win swab counts. The exception to this is a sanitizer that contains peroxide (Matrix, Oxonia, etc...) and quaternary ammonia. These two sanitizers can cause an interference with the swab reaction. This causes a false-positive. To avoid any possible interference, try swabbing before the application of the sanitizer. If this is not a viable option, try waiting 15 minutes before swabbing. This will allow the sanitizer to completely react with the equipment surface rather than the Ultrasnap or snapshot swabs.
Will direct sunlight affect swab counts?
Sunlight can affect swab results. If swabbing an area in direct sunlight or under bright florescence, do not leave swab exposed to light for more than 15 seconds and bring luminometer into lighter light or inside to run test. Activating and counting the swab in direct sunlight or in extremely bright places can cause increased RLU results.
How do I know the SystemSURE Plus and ATP swabs are functioning properly?
To ensure that the SystemSURE Plus and swabs are functioning properly, run a positive and negative control test. For a negative control remove a swab from the bag and without swabbing an area, break the Snap Valve expelling the liquid reagent down the shaft. Then place it in the SystemSURE Plus and take a reading. You should get a 0 or 1 RLU value. For a positive control, take the beta light designed for the SystemSURE Plus and place it in the read chamber and take a reading. You should get a designated number each time. If you have not purchase a beta swab, you can do so by calling (805) 388-8007. If either the positive or negative control is out of range contact your account manager at (805) 388-8007 or via email at email@example.com.