E36 TECHNICAL BULLETIN #6: 12/18/2001
Cleaning of Pavement Surfaces by Potassium Acetate Runway Deicers

Airport operators have reported the appearance of residues on airport pavements after application of potassium acetate-based runway deicers.

SUMMARY
Cryotech E36�, a potassium acetate-based runway deicer, has the ability to dislodge and lift pavement contaminates to the surface. This may cause a dark, tacky or slippery residue. Typically, this happens after the first winter application if there is not enough precipitation to clean the pavement. The residue may be removed manually by rinsing the pavement with water or by additional applications of E36 coupled with mechanical removal.

PAVEMENT CLEANING
E36 has low surface tension and high specific gravity (28% heavier than water). These properties are important to the deicerÌs performance causing it to disperse quickly and uniformly, and penetrate into the pavement surface to either undercut existing snow and ice (deicing mode) or to prevent snow and ice from bonding to the pavement surface (anti-icing mode).

These same properties also give E36 the ability to penetrate and Îdeep cleanÌ the pavement. This may result in dirt, grime, rubber, aircraft deicers, fuel, oil and other contaminates rising to the pavement surface. The residue can be tracked into buildings and may obscure pavement markings. Usually, there is enough precipitation with E36 use that any residue is cleaned away as plows and/or brooms remove it with the snow and ice.

However, if E36 is applied with light or no precipitation, a tacky residue may appear on the pavement surface. At temperatures above freezing, this residue can be washed away with water. Below freezing, it may be necessary to make subsequent applications of E36� to keep the residue mobile and continue brooming to remove it. The first significant rain or snow event usually makes the residue go away for the rest of the winter season.

PREVENTATIVE MAINTENANCE
Residues are minimized by cleaning contaminated surfaces prior to winter.

As a result of these cleaning properties, some airports have reported that E36 is an effective rubber removal chemical. Also, E36 use generally results in less rubber buildup on the runway surface.

Please note that E36 has been tested and determined to be compatible with asphalt and concrete pavements. Copies of those test results may be obtained by contacting Cryotech.