The Editor, Sir:

Our government has mandated the full roll-out of E10 gasolene but in so doing has overlooked the diverse effects which E10 will have on the fishing industry. It has widely been known that E10 gasolene should not be used for marine purposes and many gas stations around the country have posted signs accordingly.

What is E10? E10 is a gasolene blend mixture of 10 per cent ethanol (ethyl alcohol) and 90 per cent gasolene that can be used in the internal combustion engines of most modern automobiles. The purpose of using ethanol in fuel is to act as oxygenate, which increases the octane rating and helps fuel burn at a more controlled rate. Oxygenation of fuel allows it to burn more completely. The more fuel burns, the less the tailpipe emissions. Most gasolene refiners switched to ethanol-blended fuels in order to reduce groundwater pollution (and cancer-causing risk) associated with MTBE (methyl tertiary butyl ether), the chemical that had been used in the past to oxygenate fuel/gasolene.

While ethanol-blended fuels may have environmental advantages, it poses a serious threat for mariners. What are the dangers? Simply put, it is water. Ethanol absorbs water extremely well because it is 'hygroscopic' (it can absorb water directly from the atmosphere). Boats 'live' on water and many have fuel tanks that are vented to the outside air as such marine fuel systems are very susceptible to water intrusion.

'Phase separation'

E-10 can hold up to four teaspoons of water in suspension per gallon, but once water is absorbed, 'phase separation' will occur. Phase separation is what happens when the fuel is saturated beyond its capacity to hold water in solution.

Water and gasolene actually separate, and the gasolene floats on top of the water. This results in two solutions, neither of which is good for the engine or fuel system … not to mention the environment. The gasolene left behind is absent of oxygenate and has now lost its original octane value, which can cause poor running and, in some cases, engine damage.

I am, etc.,

Patrick Kumst