Sodium chlorite: Properties, Uses, Transportation, Storage, and Handling

ERCO Worldwide is a leading producer and provider of specialized inorganic chemicals and is a leading developer and supplier of chlorine dioxide production technology used in pulp bleaching. As the parent company of International Dioxcide, ERCO Worldwide has been in business for over a century and proudly upholds the reputation for excellence in delivering innovative, sustainable chemical solutions that improve lives in the health of our planet. Both International Dioxcide and ERCO Worldwide are responsible care companies and highly value the safety of each and every individual.

This video contains important information about the best practices for safe handling, transportation, and storage of sodium chlorite solutions.

Sodium chlorite is a preferred precursor for safe generation of chlorine dioxide and has been used commercially for over 75 years. Chlorine dioxide gas is unstable in concentrated form and is therefore generated at the point of application from concentrated precursors. Immediate dilution into the process being treated renders a safe and effective operation. Chlorine dioxide generators, as well as sodium chlorite, have several beneficial applications, including disinfection of potable water, wastewater odor control, oil and gas biocidal applications, biocidal treatment of industrial process and cooling water, paper mill slimicide, and as a sanitizer and disinfectant in food and beverage applications.

There are several potential hazards present in the shipping and storage processes related to the use of sodium chlorite solutions. Sodium chlorite solutions are shipped as a corrosive solution with a pH between 12 and 13. When handled and stored properly, these solutions are quite stable. Special care must be taken to avoid allowing sodium chlorite solutions to spill or dry and form a white oxidizing powder. Be aware that if sodium chlorite solutions ever react with organic materials, acids, or other stronger oxidizers, the chlorite solution will quickly liberate chlorine dioxide gas.

Chlorine dioxide gas is toxic and can be lethal at high concentrations. In rare instances, chlorine dioxide gas can explode if the concentration in air exceeds 10% or if the gas is compressed. Review your sodium chlorite safety data sheet before working with or around sodium chlorite solutions.

The most common incidents involving sodium chlorite happen as a result of the following actions: Improper or poorly implemented personal protective equipment, improper transportation and handling, allowing sodium chlorite spills to dry, which changes the chemical state from a corrosive liquid to an oxidizer, insufficiently rinsing empty sodium chlorite containers, offloading sodium chlorite into the incorrect bulk tank, adding sodium chloride to the incorrect drums or IBC totes, and storing sodium chlorite with incompatible materials.

Sodium chlorite can react with any organic materials it comes in contact with, including objects like leather boots, cotton clothing, and sneakers. Sodium chlorite is especially harmful to the unprotected human body. It is therefore crucial that anyone working with or around sodium chlorite solutions wears the correct protective equipment in order to prevent bodily injury.

The correct personal protective equipment or PPE for handling sodium chlorite solutions is as follows: Rubber boots, a neoprene suit or jacket or an approved equivalent with clasps on the inside and outer buttons fastened up to the wearer’s neck to prevent liquid from penetrating into clothing. If a neoprene jacket is worn instead of a suit, neoprene pants should also be worn. Suit or pant legs should overlap and cover the rubber boots. Rubber gloves should be worn and covered by jacket or suit sleeves to prevent the solution from running into the gloves and contacting the skin. Lastly, always wear protective safety goggles and a hard hat with a face shield.

Before working with or near sodium chlorite, perform the following checks to ensure you’re prepared for safe operation, regulatory compliance, and potential emergencies. Ensure a safety shower and eyewash station are nearby and that there is sufficient water pressure and flow from each. In the event that you become contaminated with sodium chlorite, we recommend you step in the safety shower, wash down completely, remove all clothing and keep it wet until properly disposed of. If you suspect sodium chlorite may have gotten in your eyes, use the eyewash station for at least 20 minutes and seek medical attention.

Check that bulk storage tanks meet the minimum labeling requirements, including labels for chemical name capacity, and UN 1908. Secondary containment must support at least 110% capacity of the largest tank it contains and must not contain incompatible chemicals. Ensure the unload connection point is locked and clearly identified with the UN 1908 label. Acceptable bulk tank construction is fiberglass reinforced plastic or HDPE. All other construction materials must be reviewed with the manufacturer for compatibility with sodium chlorite solutions.

Lastly, piping should be PVC Schedule 80 or CPVC. Metal piping is susceptible to corrosion and is not acceptable for sodium chlorite usage. ERCO performs a bulk tank assessment prior to your first bulk delivery. If desired, ERCO will send a customer bulk tank kit with all necessary product tank and pipe labels and locks to help ensure safe unloading and storage of sodium chlorite solutions. If you have any questions about safety equipment or procedures, contact ERCO for fast and reliable support.

ERCO and International Dioxcide’s facilities are specially outfitted for safe production use and transportation of sodium chlorite. Sodium chlorite solution is most often transported by 316 or 316 L stainless bulk tank trucks. While loading procedures may vary between sites, it’s crucial for every loading site to follow their truck loading procedure with extreme caution.

The following is an example of one truck loading procedure. After checking in with site security, the truck should arrive at the loading dock and show papers proving the truck has been thoroughly washed clean at a certified truck wash. The driver should position the truck under the loading rack and turn off the truck entirely. The truck driver and any involved personnel should ensure they have proper PPE and functioning safety equipment before beginning the loading process. The driver must not leave the truck cab while wearing normal street clothes as this puts them at risk of contamination and severe injury. Once the driver is in the proper PPE, they may be asked to assist in the loading process. If a platform is not available, drivers should be prepared to safely climb to the top of the trailer to assist with loading.

To prepare the loading site, barricades should be set up to prevent any other vehicles from entering the premises. Wheel chocks should be placed on the truck to prevent the truck from rolling during loading or unloading. Next, an operator along with site personnel will inspect the trailer to ensure everything is in order before sodium chlorite can be safely loaded. A product check is then completed to ensure the correct product is about to be loaded.

After the gangway is lowered and the dome lid opened, a final check of the trailer must be completed to ensure that it is clean and all valves are in the closed position and capped off. All process valves on the loading equipment, including the valve on the load arm, should be opened prior to beginning the loading process. This ensures there will be no unwanted pressure differential on the loading piping and pump. After carefully making these preparations loading may safely begin and the trailer should be filled to the desired mount. After the desired level is reached, the pump is stopped and the loading process valves are shut. Remove the load arm or hose from the trailer. Close the dome lid firmly and secure it with tamper-proof seals. Now that the sodium chlorite has been loaded, the truck is ready for a series of important travel preparations.

Once the truck has been safely loaded, wheel chocks and barriers are removed, the truck will be weighed out and proper identification placards must be placed on the truck. Sodium chlorite’s unique identification placard is UN 1908 and all sodium chlorite shipments must clearly display this placard.

Before the truck leaves the loading site, final documentation and clearance papers must be issued. Once clear of the possible loading area contamination, the truck driver should place the papers in a sealed compartment on the body of the tanker as well as in the door of the cab. In the event of an accident, these papers are highly important to an emergency response team.

Finally, the driver should walk around their vehicle to carefully check once more that the load is secure and the truck is mechanically fit for travel on public highways. During the delivery trip, drivers should periodically inspect their vehicle to ensure the safety and integrity of the load. If an issue is spotted or the driver has any concerns, they should contact Canutec if in Canada or Chemtrec if in the United States.

It is critical to be aware that sodium chlorite is often mistaken as sodium hypochlorite When arriving at a customer site, offloading sodium chlorite into a sodium hypochlorite tank or other tank with organic or acidic materials, may result in a plant evacuation or tank explosion and must be avoided by carefully adhering to the following steps.

Upon reaching its destination, the truck driver should check in with site security and approach the unloading point with all necessary documents. The driver must present the customer with documents declaring what product is being delivered, and the customer should acknowledge acceptance of the product by signing the document.

Prior to unloading, the driver and any involved personnel must ensure they’re wearing proper PPE and that all equipment is functioning correctly. Next, the driver should inspect the site to locate the site’s eyewash and safety shower. Then ensure the offloading area is up to standard for safe unloading.

The customer and driver should both note the fill line for sodium chlorite and inspect the condition of the receiving tank in order to confirm there is adequate space to receive the entire new shipment volume. It may be necessary to follow the fill line piping from its very beginning all the way to the tank to ensure sodium chlorite is being received into the proper storage tank.

Next, the customer should provide the driver with a key for the UN 1908 lock, located on the fill line. To prepare the unloading site, barricades should be set up to prevent any other vehicles from entering the premises. Wheel chocks should be placed on the truck to prevent it from rolling during unloading. After preparing the premises, the driver should provide a sample to the customer. The customer may perform tests on the sample to confirm the quality of the product prior to unloading. These samples are typically marked and retained in a safe storage area for future use.

Once the customer confirms that the product is acceptable, the driver may begin hooking up the unloading hoses and equipment. Once hooked up, the driver should double check all connection points to confirm they’re secure. To prevent even a small amount of sodium chlorite from contaminating the ground, catch basins or buckets should be placed beneath the connection points. The driver should verbally confirm whether the customer is familiar with how to shut off the equipment in case of emergency and clarify any safety-related questions or concerns the customer may have.

During unloading, the driver should remain at or nearby the shutoff valve. Once unloading is complete, buckets and spill pads should remain in place until all lines are disconnected and capped, and valves and hoses are plugged and stored. Following unloading and cleanup, wheel chocks and barriers are removed and paperwork should be finalized.

Many customers require 55 gallon HDPE drums or intermediate bulk container known as an IBC or tote for their applications. IBC’s consist of a plastic liner enclosed in a steel frame that protects the container from hazards and provides structural support. IBC’s with a capacity of 275 or 330 gallons are commonly used for sodium chlorite, storage and handling.

As a precaution, drums or IBC’s are filled and securely closed using a torque wrench to prevent accidental opening due to handling or vibration. Fill caps are then sealed to ensure tampering has not occurred between the time of filling and when the customer opens one for use. When transported by a forklift or hand truck, IBC’s and drums must be kept at a low level to decrease the likelihood of a drum falling and sustaining damage that may result in a hazardous event or lost product.

The safest way to ship drums is to load no more than four drums to a pallet. The drums are filled, their caps should be tightened and sealed, and all four drums should be banded together to make a secure package. Each drum should be affixed with an outward facing label for quick identification of the product and its hazards. Drum pallets should never be stacked more than too high. This will prevent the stack from becoming top heavy or placing too much weight on the bottom layer, which can lead to damaged or ruptured drums.

In case of a drum or IBC rupture, the compromised container should promptly be placed within secondary containment to allow the sodium chlorite to drain into a controlled space. As the ruptured container is placed into secondary containment, any spilled solution must immediately be cleaned up by personnel trained to safely respond to spills.

Personnel who attend to the spill should put on appropriate PPE before doing so. Once the failed container is completely drained, the contained material should be collected in an approved plastic container and properly disposed of. The failed container and secondary containment should be thoroughly washed down with water to avoid any drying of the sodium chlorite solution. Captured solution as well as any exposed incompatible material should be disposed of according to local regulations. If you’re unsure of your local regulations, contact ERCO for assistance. Note that sodium chlorite is toxic to aquatic species and should not be released to open streams and rivers.

Let’s recap all safety information covered in our safety video series. Sodium chlorite is a corrosive solution. It’s crucial to wear personal protective equipment when working with sodium chlorite solutions. Keep sodium chlorite solutions away from combustible materials, acids, and organic materials.

If a spill occurs, contain spilled solutions and clean up immediately followed by plenty of rinse water to dilute residual material. Do not allow spilled sodium chlorite solutions to evaporate or dry and leave a white powder residue on surfaces as this will change its chemical state to an oxidizer and become highly combustible. Do not allow contaminated clothing to dry as it will become highly flammable. Remove contaminated clothing immediately, soak with water, and launder if the exposure is minor. If the contaminated clothing exposure is significant, soak with water and properly dispose. Depending on its material, some contaminated PPE can be thoroughly rinsed and reused. Adhere to your loading or unloading site’s safety guidelines and procedures carefully and always follow local regulations for disposal. Only water is capable of putting out a sodium chlorite fire. Never smoke in a sodium chlorite workplace.

ERCO and International Dioxcide care deeply about the safety of our customers. Our friendly and knowledgeable support experts are happy to assist you with any questions or issues regarding the safe and successful use of sodium chlorite. To learn more about ERCO Worldwide and International Dioxcide, reference the contact information on your screen or visit ercoworldwide.com. Or call 1 800-477-6071.