Sodium hydroxide, also known as lye or caustic soda, is used to neutralize the pH of water in a variety of applications. Sodium hydroxide is produced by the electrolysis of brine or by reacting sodium carbonate with calcium hydroxide. The chemical leaves no residual color, is a high-strength product, and is available at concentrations of two to 50 percent. Most of our customers use it in 25 to 50 percent concentrations.
Sodium hydroxide has a wide variety of uses such as making paper, water treatment in corrosion and scale control and pH adjustment, metal cleaning, electroplating, fuel cell production, medicine and even food processing. It can be found in many household items such as drain cleaner, detergents, and bath soaps. While this chemical is widely used, its properties present special storage and handling challenges.
At room temperature, sodium hydroxide is a white solid that can be found in flakes, granules, or pellets. In liquid form, it is colorless and denser than water. It also becomes slippery and tends to find weak points in storage containers, which can result in leaks. When dissolved in water or neutralized with acid, it releases substantial amounts of heat that may be sufficient to ignite combustible materials.
In all forms, sodium hydroxide is highly corrosive and reactive. As a solution, it reacts with many metals, including aluminum, magnesium, copper, and zinc.
It also reacts readily with organic tissue such as human skin or eyes. Exposure to sodium hydroxide, even if only for a few seconds, can result in permanent eye damage and severe chemical burns. For this reason, it is critical to ensure that caustic soda is handled and stored properly.
When evaluating your storage options, make sure you consider these two crucial elements:
While there are many options for Sodium Hydroxide storage, a rotationally molded cross-linked polyethylene tank is ideal. This process produces a tank with no seams, making it nearly impossible for the chemical to find leaks.
Because of its hazardous and highly corrosive nature, it is important to have a double-wall containment system for caustic soda. Poly Processing’s SAFE-Tank® is a double wall tank system, a “tank-within-a-tank” that provides secondary containment to avoid the damaging of equipment or property, loss of chemical, or injury to employees in the event of a spill. The tank is designed to keep contaminants from entering the interstitial space, preventing contamination of any chemical that has leaked out of the primary containment space.
The SAFE-Tank® Double Wall Tank System:
The SAFE-Tank system provides at least 110 percent containment within the same footprint as a vertical storage tank, making it easy to store the chemical wherever it’s most efficient and convenient. In addition, the tank's high-density XLPE construction means greater strength and longer life. It’s so strong that Poly Processing Company offers a five-year full warranty.
IMFO® Tank System
It’s also important to consider the tank fittings. Poly Processing’s Integrally Molded Flanged Outlet (IMFO) Tank fitting is an ideal choice, because the flange is actually a molded part of the tank itself, rather than an insert that could leak or fail. The IMFO fitting also ensures long-term performance of the overall system, because it eliminates the need to drill into the tank's sidewall to install a mechanical fitting.
Our IMFO Tank is a homogenous flange system that is molded as part of the tank while it’s being manufactured, making it a stress-free part of the tank. The flange is created from the same material as the tank — it’s not an insert added during or post-production.
Some companies create tanks out of one substance and insert a metallic flange post-production, for drainage and discharge. This is simply to save money on investing in proper tooling to make the right tank. An inserted metallic flange is common in the tank industry, but there are critical benefits to using a molded full discharge fitting or IMFO.
Advantages of the IMFO Tank include:
If you already have concrete containment in place at your facility, the IMFO Tank is our recommended tank system for storing Sodium Hydroxide.
Our tank systems are NSF-Certified to store Sodium Hydroxide as well.
Whatever tank configuration you choose, it will be important to maintain proper temperatures inside the tank. For polyethylene chemical storage tanks, heating pads and insulation can maintain the specific temperature of the chemical you’re storing—even when your chemical tank is exposed to low air temperatures.
Poly Processing’s chemical tank heating system comprises tank heating pads and a temperature controller with thermostat. The quantity and size of the silicone heating pads depend on the size of the tank, the required chemical temperature, and ambient environmental conditions.
Learn more about sodium hydroxide storage — Download our sodium hydroxide chemical storage guide.