Winter is approaching fast. With below freezing temperatures and snowstorms affecting millions of people each year, municipalities need to be ready to clear roadways and maintain equipment. De-icing fluid is used to break down ice and frost on roadway surfaces and aircraft.
The substance used for de-icing depends on its application, the amount of snowfall, the municipality’s preferences, and winter temperatures. A variety of chemicals are used in the de-icing process, including brine, magnesium chloride, propylene glycol, and ethylene glycol. Brine is the most popular of these chemicals, but it can damage vehicles or rebar on roadways.
On roadways, de-icing fluids are used to break down snow and ice and to provide a safe passage for drivers. De-icing fluids are also used on airplanes, to ensure that critical sensors, ports, and mechanical equipment remain unblocked during flight.
Whichever chemical is used, and wherever it is used, during the de-icing process, it must be stored safely so that the integrity of the chemical isn’t compromised and that it’s properly contained.
Considerations for Storing De-icing Fluids
Properly storing de-icing fluid is critical in order to protect the environment and to maintain chemical integrity. Poly Processing’s SAFE-Tanks® are double-wall tanks, which are engineered to safely store de-icing fluids such as these:
Brine is the most popular de-icing fluid because of its low cost, but it has limitations in lower temperatures and areas where salt damage cannot be tolerated.
Magnesium chloride (also called MAG) is often used on streets in areas with very low temperatures. MAG was once thought to be a safe and powerful ice melting solution. However, we now know it can damage concrete. Any MAG spill that occurs can run the risk of contaminating the natural resources around the tank.
Ethylene glycol is much more expensive than brine or MAG and is used more often on aircraft. Ethylene glycol isn’t recommended to be stored with linear high-density polyethylene tanks. Cross-linked polyethylene should be used to safely store ethylene glycol.
Propylene glycol is often used as a safer, less toxic substitute for ethylene glycol in aircraft de-icing applications, but it must be handled properly because of its potential for contamination. With a specific gravity of 1.04 and cold temperatures, cross-linked polyethylene is the recommended material for storage tanks.
Related Content: Secondary Containment Guide
Using a SAFE-Tank to Store De-icing Fluids
The SAFE-Tank system is a double-wall containment and storage system built from cross-linked polyethylene. The “tank-within-a-tank” configuration means there is no need to designate a large area for a concrete containment structure. In the rare case of a spill, the risk of damage or lost product is normally mitigated with very little downtime.
The value of a SAFE-Tank includes a built-in secondary containment tank that won’t compromise chemical quality in case of a spill. If damage occurs to the inner tank, the system works to equalize the liquid level so that you can keep storing the chemical in the containment tank until the product inside has been used. This means most necessary tank repairs are not emergencies, saving you critical time and money.
The dome structure of a SAFE-Tank helps to prevent water and debris from entering the containment tank, which eliminates the risk of false positives for leak detection.
The SAFE-Tank system allows de-icing chemicals to be double-wall piped from the tank using the industry’s only fully contained double-wall tank transition fitting. This important fitting meets 40 CFR 264 requirements and drains the primary tank through the containment tank while acting as a secondary containment around the fitting.
40 CFR 264.193 states that double walled tanks must be:
- Designed as an integral structure (i.e., an inner tank completely enveloped within an outer shell) so that any release from the inner tank is contained by the outer shell;
- Protected, if constructed of metal, from both corrosion of the primary tank interior and of the external surface of the outer shell; and
- Provided with a built-in continuous leak detection system capable of detecting a release within 24 hours, or at the earliest practicable time, if the owner or operator can demonstrate to the Regional Administrator, and the Regional Administrator concludes, that the existing detection technology or site conditions would not allow detection of a release within 24 hours.
Full-Drain Storage Option
If containment isn’t an issue, Poly Processing recommends the Integrally Molded Flanged Outlet® (IMFO®) system for complete discharge of the de-icing product. This true full discharge solution eliminates many of the problems that other full discharge systems experience.
With our innovative IMFO System, the flange is molded into the tank during manufacturing, rather than being introduced post-production as an insert. IMFO-style fittings are made from the same material as the tank, creating a one-piece, homogeneous unit. Because the IMFO fitting is part of the tank itself, there is no added stress on the lower sidewall. IMFO Tanks are available in vertical and slope-bottom configurations.