BID specifications

Deicers meeting FAA standards vary in formulation and have different performance characteristics - see following graph. It is, therefore, important to pay close attention to bid specifications written into product solicitations. Failure to properly consider all the elements associated with product formulation, product quality, product performance, and the manufacturer’s ability to supply can compromise airport operations. See the guide specification for anhydrous grade sodium acetate.

Product application

• NAAC may be used in the same manner as urea. However, less NAAC will be required to accomplish the same deicing objective, because it is more effective as shown by the accompanying ice penetration graph. In 1993, Transport Canada reported the following test results: “The required application rate for sodium acetate is about two-thirds of that for urea to achieve similar effectiveness”.
• NAAC may be used as an anti-icer or as a deicer.
• NAAC’s effectiveness as a deicer - to melt through pack - is enhanced by prewetting with E36 at the spreader spinner. Prewetting causes NAAC to stick and begin melting almost immediately after application. The freezing point of the combined products is lower than that of NAAC alone.
• NAAC may be used as an anti-icer, applied just as the storm event begins. With a small amount of precipitation on the surface - freezing rain, ice or snow - NAAC will activate, and keep ice bonds from forming at the surface. This anti-icing strategy is an effective addition to liquid anti-icing programs during freezing rain conditions.
• NAAC may be used in conjunction with E36 to solve serious pack conditions. First, apply NAAC to the pack. After holes are punched in the pack, apply E36 - the liquid then has a path to the pavement surface and quickly breaks the pack prior to mechanical removal.
• The amount of NAAC to be applied is determined by the surface temperature, the ambient temperature, and the quality and quantity of pack. Conditions vary; therefore, the application rate guide suggests starting points to be adjusted locally as required. The guide provides application rates on light ice that achieve a wet, ice-free surface at various temperatures.
• Generally, the longer ice remains, the stronger it bonds to the surface, making removal more difficult. For this reason early application enhances the effectiveness of deicers.

Deicer freezing points

Deicer freezing points were determined by Michigan Tech using standard U.S. Federal Highway Administration test methods. Freezing point is fundamental in assessing the effectiveness of deicing chemicals, that is, the lower the freezing point the more efficient the deicer.

Prewetting

NAAC is most effective as a deicer when prewet at the spreader spinner with E36 Liquid Runway Deicer. Begin at 10% E36 by weight of NAAC and adjust for local conditions.

Exothermic versus endothermic

NAAC is exothermic meaning it gives off heat as it dissolves. Trihydrate grade sodium acetate and urea are endothermic, actually absorbing heat as they go into solution. Because it is exothermic, NAAC penetrates ice faster (see ice penetration graph). This advantage is depicted another way in the following graph of laboratory tests. The deicers are dissolved in water and the resulting maximum temperature change is measured at equilibrium. The dilute solution containing NAAC warms by 12°C; while trihydrate and urea absorb heat and cool the water by 16°C.

Environmental impacts & hazard information

Tests with NAAC show it readily biodegrades at low temperatures and has a relatively low biological oxygen demand (BOD) compared to urea. Toxicity tests rate NAAC as “relatively harmless” to aquatic life, the most favorable classification used by the environmental community. Urea’s breakdown product - ammonia - is toxic to fish. For these reasons, NAAC is considered safer for the environment than urea.

More information about the enviromental impact can be found in the Material safety data sheet.

Roads, parking garages and walkways

NAAC is a good choice for non-airside applications, primarily because it does not contain chlorides that cause corrosion to steel embedded in concrete. Additionally, NAAC does not track like common salts and is effective at much lower temperatures, 5°F (-15°C), than sodium chloride and urea, which lose their effect below 20°F (-7°C). Note: If concrete quality is the primary concern - for example, a deicer is required for a new slab of concrete - then Cryotech CMA® is recommended, because it is safer for concrete.

Spill handling procedures

NAAC is not expected to present environmental problems. If NAAC should spill or otherwise be unsuitable for normal airside applications, it may be used in an alternate manner for deicing non-airside surfaces or as an additive to sand. Product unsuitable for any use may be disposed of in a sanitary landfill unless state or local regulations prohibit such disposal.

Certification to FAA specifications

The FAA has established standards for solid runway deicers. At this writing, SAE AMS 1431A covers all solid deicing/anti-icing compounds including NAAC. This specification identifies material and environmental properties, and establishes minimum standards for material compatibility and performance. NAAC meets or exceeds all requirements of this standard as indicated below. Current certifications are supplied at customer request.