E36 TECHNICAL BULLETIN #5: 4/21/98 (Revised 9/6/00)
Material Compatibility of Potassium Acetate Runway Deicers

Customers frequently ask if material in their storage, handling, and application equipment is compatible with potassium acetate runway deicers. There are technical differences between potassium acetate deicers from various producers, usually in the formulation of corrosion inhibitors. Therefore, some differences in material compatibility are expected. The following information applies to Cryotech E36, which is 50% potassium acetate, by weight.

CORROSION INHIBITORS
Cryotech E36 contains less than 1% proprietary corrosion inhibitors, which create a protective barrier on the surface of metals used to contain the fluid. The performance of corrosion inhibitors in usually tied to the pH of the fluid. Diluted E36 biodegrades naturally when exposed to air and other contaminants. By-products of this activity can result in unsightly biological growth and superficial staining/corrosion. Therefore, the exterior of application equipment should be rinsed routinely with warm water.

EQUIPMENT CONSIDERATIONS
When selecting equipment to transport, store, and apply potassium acetate runway deicers, the following guidelines should be considered:

Pumps: Stainless steel, positive displacement pumps preferred. Avoid brass, cast aluminum, and cast iron, because some castings are porous and may leak; avoid large bore, low head (pressure) centrifugal pumps.
Pipes: Stainless and carbon steel, PVC, polyethylene, and rubber are okay. Avoid galvanized metals, because E36 will react slowly with zinc giving off hydrogen gas.
Tanks: Stainless steel, fiberglass, or polyethylene is preferred. Carbon and alloy steel tanks may be used if clean and rust free.
Seals: Butyl rubber, ethylene propylene rubber (EPM, EPDM), isoprene, natural rubber are preferred. Nitrile (Buna N), hypalon, neoprene rubber are generally acceptable. Avoid butadiene, fluorocarbon rubber, fluorosilicon, polyacrylate, polyurethane, SBR rubber (Buna S), silicon rubber.

INSTALLATION CONSIDERATIONS
Use good engineering practice when installing piping and equipment. Provide relief valves, low point drains, and make sure block valves can be opened without operator risk. Avoid dissimilar metals, or provide properly engineered insulators to minimize the effect of galvanic corrosion. Potassium acetate has low viscosity and low surface tension. Therefore, high quality joints are needed for a leak-tight system. Welded or fused pipe joints are recommended. If threaded fittings are used, a high quality pipe sealant is recommended.

AVOID PROBLEMS...
Do not use potassium acetate runway deicers with galvanized (zinc-plated) metals.
Do not use potassium acetate on poor quality concrete.
Do not mix potassium acetate runway deicers from different manufacturers.

We welcome any questions you may have regarding this or other technical matters. Feel free to contact our General Manager, Keith Johnson, at 712/526-2407; or contact our Fort Madison, Iowa plant at 800/346-7237.