Currently, there are no turbine fluids in the marketplace that can match the fire safety properties (flash point, self-extinguishing) of phosphate esters such as Fyrquel. It stands alone, but it has some serious drawbacks.
There are also very few fluids that have the levels of toxicity that phosphate esters do. This is why you should always wear gloves when handling the fluid and have to be extremely careful when handling items that contact the fluid to minimize the impact on the environment from the use of phosphate ester.
There are also few fluids that require the same level of care to keep the fluid in good shape. Proper use of filtration equipment that includes good particulate filtration, as well as a Selexsorb GT cartridge is critical to keeping the fluid in good shape.
A PAG (polkylene glycol) such as Ecosafe has excellent environmental qualities (biodegradability, toxicity) compared to phosphate esters, but doesn't have great fire prevention properties.
POEs (polyol esters) are also good alternatives to phosphate esters that have excellent biodegradability and toxicity results compared to phosphate esters, and usually have a flash point close to most phosphate esters, but do not have the self-extinguishing characteristics of phosphate esters.
Phosphate esters have big advantages over POEs and PAGs in its flash point and self-extinguishing characteristics.
POEs and PAGs have big advantages in initial fluid cost and cost of ongoing filtration. They also have tremendous environmental benefits.
All of the three fluids should be able to get FM approval for gas turbine use in their final form.
Some power producers currently have additional financial and environmental pressures that may make it worthwhile to consider a fluid other than a phosphate ester. Others may decide that it would be better to save money or "green up" other areas of their operation.