the Stansted runways on Sunday with 15cm of snow were very quickly cleared On the local BBC news they showed the chemical dispensers they used, very long swing out spay bars Said they used Potassium acetate as it was non corrosive, so looked it up what a load of good uses it has http://en.wikipedia.org/wiki/Potassium_acetate
Potassium acetate can be used as a deicer instead of chloride salts such as calcium chloride or magnesium chloride. It offers the advantage of being less aggressive on soils and much less corrosive, and for this reason is preferred for airport runways. It is, however, more expensive. Potassium acetate is also the extinguishing agent used in class K fire extinguishers because of its ability to cool and form a crust over burning oils. In medicine, potassium acetate is used as part of replacement protocols in the treatment of diabetic ketoacidosis because of its ability to break down into bicarbonate and help neutralize the acidotic state. Potassium acetate is used as a food additive as a preservative and acidity regulator. In the European Union, it is labelled by the E number E261; it is also approved for usage in the USA and Australia and New Zealand.