Product FAQs

Yes. MicrobMonitor®2 is a simple and easy to use test kit which enables the quantitative assessment of the viable microbial content in petroleum products including liquid fuels, oils (including Lubricants) and associated water.  The volume of sample tested may be varied depending on the type of sample to give the most appropriate sensitivity range.   Advice on the most appropriate volume to test is included in our Instructions for Use document.

The frequency with which you test will be dependent on the system being tested and the operational experience and the perceived risk.  Recommended practice is to start monitoring at a higher frequency than anticipated for routine testing to determine the risk of contamination.  Once a good track record is established the frequency of monitoring can be relaxed.

Example: Typically, a low-risk fuel storage facility might monitor fuel storage tanks annually after an initial monthly to quarterly screening for 1 year.  High risk facilities would maintain a monthly monitoring program.

For aircraft tanks which are well aerated, MicrobMoinitor®2 is suitable for detecting the Microbes which are likely to be present.  For fuel storage tanks where bottom waters can be present persistently and sometimes become stagnant, ‘anaerobic’ Sulphate Reducing Bacteria (SRB) can grow. The Sig Sulphide test will enable you to detect SRB and the associated risk of corrosion.

MicrobMonitor®2 was specifically designed to test fuel samples directly.  It quickly gained approvals in the aviation industry for testing jet fuel and is listed in the Aircraft Maintenance Manuals of Boeing, Airbus and other leading  aircraft OEMs. Major airlines have been using MicrobMonitor®2 for many years and it is seen as a trusted reference method.

MicrobMonitor®2 has been independently validated in an inter-laboratory study conducted for the Energy Institute and enables testing in accordance with IP Standard Method IP 613 Determination of the viable aerobic microbial content of fuels and associated water – Thixotropic Gel Culture Method.  The test also gives results which compare very well with the laboratory standard test methods IP 385 and ASTM 6974-03.

The test is used by the military and is a codified NATO stock item (Stock No. 6640-99-834-3573).

• Works with any petroleum product and associated water
• Approved by major OEMs and oil companies and adopted widely
• Quick and easy to use, more economic than laboratory tests
• Uses the reliable and trusted colony forming unit (CFU) technology
• No specialist skills or equipment required
• Results are comparable with IP 385 and ASTM D-6974-03
• Capable of detecting a developing contamination for an early warning of potential problems
• Fully Quantitative, indicates the severity of an infection not just the presence of microbes as with “go, no-go” tests
• Unaffected by biocides, DIEGME or additives so can validate the efficacy of the treatment
• Only detects live microbes and mould spores, other tests can give a positive result for hours or even days after microbes have been killed by a biocide treatment
• Both Oil and Water phases can be tested giving reliable results
• Detects Hormoconis resinae, other moulds, yeasts and bacteria
• Detects mould spores which some other tests cannot

It is important to break up the gel in the MicrobMonitor®2 test and shake thoroughly (30 seconds recommended) to disperse the sample in the gel. Inadequate shaking can result in lumpy gel and can result in patchy growth which can make test results more difficult to read and interpret.

Tap the bottle sharply several times (in the palm of your hand) to break up the gel before you shake it. Some users tap the bottle several times on a large rubber bung. Other users warm the tests to about 30°C (86°F) before use; this makes the gels easier to shake. We supply MicrobMonitor®2 Bumpers for those who test very frequently.

Possibly not – The stability of fuels and lubes, particularly those formulated with bio-ingredients, is often improved by suppliers, by adding anti-oxidants. These can react chemically with one of the ingredients of the MicrobMonitor®2 test, resulting in a pink/peach background colour. This sometimes occurs within a few hours and does not interfere with the growth of microbes transferred from the sample. Microbial growth produces deep red colonies in the gel which can easily be seen despite the pink/peach background. To reduce the effect, you can test smaller volumes of sample, for example 0.1 ml of bio-diesel instead of 0.25 ml. Then use the 0.1 ml section of the interpretative chart.

Some bacteria are motile (they can swim), and they sometimes swim on the surface of the test gel to form purple or red patches or streaks. The patches often have uneven colour intensity. Usually, the problem only occurs when testing water samples or fuel samples containing suspended free water.

• Look at the test after 1 or 2 days, before the patch has spread out; count the colonies marking them with a felt pen. If when observed again (e.g. at 4 days) a spreading patch is present, this should be ignored, and only new discrete colonies should be counted and added to the total count.

• If it was not possible to observe the test before the patch spread, it is often possible to see through the patch and distinguish and count discrete colonies as usual. The patch tends to have a lighter colour intensity than discrete colonies and is not clearly demarcated. Each patch should be counted as one colony and added to the total count of colonies. If it is difficult to determine where a patch begins and ends, record a count of “1” colony for the whole patch or streak and add this to the total count of colonies.

• If it is not possible to distinguish and count discrete colonies through the colour patch, count only an area of the gel which is not affected and multiply the count by an appropriate factor for the final result (e.g. count half of the gel area and multiply by 2).

• If using the interpretation chart to estimate the total number of colonies, try to ignore the patch and estimate only on the number of discrete colonies; if necessary, estimate the intensity of colonies based on an area of gel which is unaffected by the patch.

• You may also send a photograph of any unusual results to info@echamicrobiology.com and we will do our best to interpret the result for you. If, none of the above are possible, it may be necessary to repeat the test taking the avoidance precautions described below:

• We recommend standardising the procedure for testing fuel system samples. Inverting the sample 3 times and then allow it to stand for 12 minutes then draw sample from 3 cm below the surface of the fuel, avoiding transfer of visible interfacial particulate, water droplets or emulsion. If there is less than 6 cm depth of fuel phase, then draw sample from about halfway down the fuel phase. The water phase or interface can be tested separately if required (0.01ml recommended)

• If you are testing water, you can reduce the chances of getting spreading bacteria and improve the ability to discern individual colonies by testing only 0.01 ml volumes of water using the dispenser provided.

• Use an incubator to keep the temperature constant and reduce condensation on the gel.

• Shake the test properly after adding the sample. Always ensure the gel is properly broken up and then shaken vigorously with sample for the full 30 seconds. Streaky or patchy growth in the test is more difficult to interpret if the gel is not properly shaken and the gel remains lumpy.

There are no microbiological standards in any fuel specification and the limit values suggested can be changed according to the local perceived risk and local operating experience. Large oil companies and major fuel users often have their own in-house limit values.

MicrobMonitor®2 is available in packs of 5 tests or in a bulk pack of 50 tests.  The normal packs include all that is needed to conduct the test including sterile syringes and loop dispensers for measuring sample into the test. For users who have their own sterile measuring devices, a bulk pack is also available which does not include syringes or loop dispensers. Such accessories  can also be purchased separately as required.

Yes, unlike other technologies, MicrobMonitor®2 can be used immediately after biocide treatment to check that the treatment has worked. Note: As instructed by the biocide manufacturer you will still need to allow the biocide a soak time to work before testing to check its efficacy.

If there was significant visible microbial contamination in the tank, there would already be a risk of filter clogging incidents. The ‘moderate’ and ‘heavy’ contamination limits as defined by IATA and repeated in OEM’s manuals, are set at levels which enable corrective treatment with a biocide or cleaning + biocide, before there is an operational problem. They do not necessarily mean that the fuel is unfit for use at that time or that the tank will be grossly contaminated.

This probably suggests that that the fuel uplifted or imported into the tank was already heavily contaminated and the growth is not likely to have occurred in your tank.

This could either mean that dirty water (sea water, wash water or environmental water) has entered the tank, or that fuel turnover in the tank is such that growth in the water phase does not yet extend up into the fuel phase. In either scenario drain off the water before the microbes adapt to grow in your tank and penetrate the fuel phase

Yes, if you refrigerate the product from point of receipt (store between 2-8°C in the dark) and have purchased it either directly from ECHA or from an Authorised Distributor, then the shelf life can be extended by up to 10 months. Specific expiry dates for different storage conditions are printed on the batch label of MicrobMonitor®2 test kits.

We do not recommend storing MicrobMonitor®2 frozen as the properties of the gel will change after several weeks. It is however acceptable for MicrobMonitor®2 to become frozen for short periods e.g. during transport

Tests showing any positive results contain microorganisms and should be handled carefully. Avoid touching the inside of the bottle or cap. Dispose of used tests showing microbial growth by one of the following methods: autoclaving, incineration, or by disinfection followed by disposal.

Wash your hands and work surface after disposal with antibacterial soap.
Used kits can be sterilised by immersion (opened) in a strong disinfectant solution overnight (e.g. 1 in 10 dilution of 5% sodium hypochlorite).
After sterilisation, bottles should be disposed of in accordance with local waste disposal regulations.

The recommended incubation temperature is 25°C ±3°C, however where the normal operating temperature of the system tested is higher, it may be appropriate to incubate at the temperature of the system tested. Because MicrobMonitor®2 tests will become increasingly more fluid at temperatures above 40°C it is not recommended to incubate above 40°C as the developing microbial colonies are not likely to remain as discrete colonies during growth. Microbes which are not adapted to growth at temperatures higher than the recommended incubation range are unlikely to grow at elevated temperatures

The shelf life of MicrobMonitor®2 test is 12 months and 2 weeks from date of manufacture when stored between 2 – 22°C, in the dark. The extended shelf life is an additional 10 months when product is stored between (2-8°C) in the dark.
Store MicrobMonitor®2 tests between 2 – 22°C, in the dark.

Do not expose to strong sunlight during use or storage. Do not store frozen. Temporary exposure to freezing temperatures during transport will not adversely affect the product. A slight pink colouration in the MicrobMonitor®2 gel may develop over time during storage but this will not affect the performance of the test.

Expiry dates are printed on the product batch label. Expiry dates apply strictly to product stored as stipulated.