'Food-grade' antifreeze safely deices planes
ELIZABETH WILSON · Chemical & Engineering News · 1997
A newly patented anti-icing agent developed by researchers at the National Aeronautics & Space Administration's Ames Research Center in Moffett Field, Calif., is so innocuous that all the ingredients have a government "food-grade" rating. And a tint of food coloring gives the material a deep green hue that has earned it the nickname "green goop." Like many materials designed to prevent ice from settling on aircraft waiting for takeoff, the Ames fluid has a base of propylene glycol and water. Unlike most commercially available fluids, however, the other ingredients that impart manyof the crucial anti-icing properties are also benign, Ames researchers say. "The problem with [anti-icing agents] that use propylene glycol is that the additives are highly toxic," says NASA Ames engineer and coinventor John Zuk. Researchers at the University of Pennsylvania performed lab tests on the fluid and concluded that it surpassed other fluids in environmental safety. "It is environmentally ...