General packaging of liquids can take many forms and deciding which packaging set-up is appropriate depends on several factors including viscosity, flammability, reactivity, corrosivity, and quantity.

Hazardous Communication

Regardless of container size, a common feature of all hazardous material packaging is Hazardous Communication. According to the United States Department of Labor, the following is stated regarding Hazard Communications:

“In order to ensure chemical safety in the workplace, information about the identities and hazards of the chemicals must be available and understandable to workers. OSHA's Hazard Communication Standard (HCS) requires the development and dissemination of such information:

Chemical manufacturers and importers are required to evaluate the hazards of the chemicals they produce or import, and prepare labels and safety data sheets to convey the hazard information to their downstream customers;

All employers with hazardous chemicals in their workplaces must have labels and safety data sheets for their exposed workers, and train them to handle the chemicals appropriately.”1

During transport, placards are placed on shipping containers with an NFPA Hazard Diamond representing the hazardous level and critical information of the material inside. An example of this symbol and its descriptions are shown in Figure 1.

Hazard Communication is vital to ensuring the responsible transportation of hazardous chemicals around the world. The information mandated is critical when facing unexpected spills or accidents. An emergency spill or response number is also included on transport containers to aid in the proper handling and clean-up in case of a release.

Vessel Type

In addition to Hazard Communication, most packaging sizes use one of two materials of construction - metal or plastic/composites. If the hazardous liquid is corrosive, a plastic container is used. When the hazardous liquid is flammable, a metal container is used, which allows the package to be electrically grounded and prevent static buildup or discharge.

Pails

One of the smallest forms of liquid packaging is a pail. Pail sizes can vary from as low as a gallon to around five or six gallons. These forms of packaging are the least sustainable as they are generally one-use and non-recyclable.

When compared to alternative forms of packaging, pails are considered the most expensive per weight of the material package. Pails typically require extra shipping materials such as pallets and shrink wrap to bundle several together at once. Pails are often shipped to the end user. This could be retail or small business, but generally, the quantities are very small. Pails also pose significant spill hazards as they can be easily damaged.

Drums

Drums are the most common industrial packaging. A typical size for a drum is 55 gallons and can be metal, plastic, or fiber.

Drums meet most regulatory requirements for warehouse storage as they are conveniently bundled with four to a pallet. Drums are more sustainable than cans or pails, but not as sustainable as larger storage and transport vessels. Although they are more expensive, metal drums can be refurbished and reused multiple times. Plastic drums cannot be reused for different chemicals.

Totes

Totes can vary in size from 2500 gallons to 3300 gallons. Composite (plastic) totes are often the cheapest and most common option. They are reusable and recyclable. However, plastic totes are not as durable and are not recommended for long-term warehouse storage of flammable liquids. The totes are at a high risk of puncture and cannot be grounded like their metal counterparts.

Metal totes are an alternative to plastic totes and hold a similar quantity of material. Metal totes are not economically preferred for shipping. While they are durable and easily connected to transport equipment, they are more expensive to produce and heavy, which limits the amount transported on a truck. Metal totes can be used as long-term or intermediate storage in warehouses and are easily reused, however, this often comes with cleaning expenses.

Tanker Vehicles

Bulk tanker cars are the most sustainable option for hazardous liquid transport. They can be reused for many years and are the most economical long-term. Tanker vehicles and their vessels are held to the strictest regulations. “FMCSA regulations require that all truckers who are transporting hazardous materials (HazMat) must first undergo training, acquire safety permits, and follow specific guidelines during transport to secure overall safety.”2 Also, the NFPA Hazard Diamond and Hazard Communication must always be visible on all sides of the vessel. There are significant regulators on pneumatic controls to prevent the buildup of pressure. Often, the vehicles are specially made to address specific hazards such as flammables, corrosives, or liquidized gases. Bulk tankers can be used for both storage and intermediate transport container.

When it comes to the railway, there are usually two types of tanker cars: General Purpose and Pressure. “Pressure tank cars–designated by the DOT-105 and DOT-112 standard specifications–are used to transport liquefied compressed gases under pressure, as well as some low-pressure, high-hazard materials.”3

Hazardous materials, or “hazmats”, are regulated by the U.S. Department of Transportation. Figure 9 shows the Hazmat shipments by class in the US and Canada in 2018. Flammable liquids represent 49.2% of Hazmat transports.

Conclusion

Hazardous liquid transport can be accomplished through a variety of containers and shipping methods. Two common factors among all these formats are the Hazard Communication requirements and the training associated with handling these containers. Despite the size or composition of the shipping or storage container, it is vital to handle hazardous liquids carefully and methodically in ways that minimize the risk of accident or release and ensure continued safety for company employees, transportation individuals, and surrounding communities.

References

“Department of Labor Logo United States Department of Labor.” Hazard Communication - Overview | Occupational Safety and Health Administration, https://www.osha.gov/hazcom.

“Dangers of Hazardous Truck Cargo Materials.” Nickelsporn & Lundin, P.C., 23 Jan. 2015, http://www.thelawyersnetwork.com/blog/types-of-hazardous-material-transported-by-semi-trucks.cfm.

“Tank Car 101.” Tank Car Resource Center, https://tankcarresourcecenter.com/tankcar101/#:~:text=THERE%20ARE%20GENERALLY%20TWO%20BASIC%20TYPES%20OF%20TANK,the%20most%20commonly%20known%20general%20purpose%20tank%20car.IBC Factsheets Code Fire Officials - Nfpa.org. https://www.nfpa.org/-/media/Files/News-and-Research/Resources/Research-Foundation/IBC/Fact-sheets/ibc-FactSheetsCodeFireOfficials.ashx.

“49 CFR § 173.33 - Hazardous Materials in Cargo Tank Motor Vehicles.” Legal Information Institute, Legal Information Institute, https://www.law.cornell.edu/cfr/text/49/173.33.