We do not utilise the traditional growth methods employed by all the other “rapid” tests currently on the market. Our kit is an immunoassay test (rather like a pregnancy test). This means that we detect contamination by “finding” material that is produced by our target organism during growth on fuel. We do not, therefore, need to capture a part of the living organism and grow it up. This is important as the fungus we detect (Hormoconis resinae, also known as Cladosporium resinae or the jet fuel fungus) does not just float around at the water/fuel interface like the other ones, it actually sticks to the bottom or sides of the tank. It is also important as our compound is spread throughout the liquid of the tank, not just at the interface. There is, therefore, a better chance of finding that compound in a small sample. The result is a more accurate and consistent answer.
We go for the single target organism because it is the most dangerous (which is why it is the one name that most people in the industry will know) and it is present in the vast majority of cases of significant contamination (somewhere in the mid 90s per cent). We also only detect the fungus if it has been growing in fuel – the kit will ignore any fungus that has been blown in from outside or has been growing on trees or other food source. The other tests will grow whatever they find in the sample – whether it came from the fuel or not. They require sterile sampling conditions, we just require that the sample equipment is clean (i.e. has no residue from the last test sample).
The Fuelstat™ resinae test takes 10 minutes to operate. The other tests take a minimum of 2 to 3 days to give a full picture of bacterial contamination. As fungal spores will not even show significant growth before 4 days a complete answer using traditional growth techniques takes five to seven days. During that time all the competitor products have to be incubated, and many have to be monitored daily.
The results of most of our competitors are deduced either by comparing colours or spot numbers with a chart or (if you need to be very accurate) counting under a microscope. In our test you look at the two lateral flow devices on the test kit paddle and read off whether you have negligible (we never say nil), moderate or heavy contamination. The levels for moderate and heavy contamination appear in the IATA guidelines.
Most of our competitor kits require special handling, certainly for safe disposal. Ours (apart from the fuel itself of course) can be chucked in the nearest bin when the test is finished or recycled if your company has a plastics recycling policy.