Hazardous Waste Shipping Containers

• By Tom Hobson
• Feb 01, 2002

Next to the corrugated carton, a 55-gallon steel drum is probably the most common container used in industry. Although most of them look identical, there are differences that should be considered when purchasing or reusing steel drums for storing, shipping or handling hazardous wastes.

In a common life cycle, a drum arrives at a facility holding a virgin solid or liquid that will be used somewhere in a process. Often, when the drum is emptied, it is crushed and sent to a scrap recycler, or it is saved to hold a processing waste. Although it would seem likely that the drum is safe for storing and/or shipping the waste, this may not always be the case. If the container has not been tested and is not properly rated, it could potentially leak, creating a slippery and potentially dangerous mess. It could also become damaged during shipment, causing problems for the transporter and potentially subjecting you to large clean up costs and fines.

One inherent problem with reusing drums is that spent liquids or solids have often picked up hazardous constituents during their use. Before using any container to collect, hold or ship hazardous wastes, you need to be certain that what you are putting in the drum will not react with it. Naturally, if there is a potential for this happening, an alternate container should be chosen. Also, if the waste is hazardous, look for a United Nations (UN) marking on the container. If the original product shipped in the container was not hazardous, the drum may not be UN rated, and would not be suitable for hazardous waste shipments.

If a drum is UN rated, the UN markings will be stamped on the drum. These markings let you know that the container has been tested to meet the Performance Oriented Packaging (POP) standards outlined by the Department Of Transportation (DOT) at 49 Code of Federal Regulations (CFR) 178. A typical UN marking looks similar to one of the following:

UN 1A1/X1.5/300

Or

UN 1A2/X430/S

These numbers tell you about the container and what types of materials can be shipped in it. The first part of the marking tells you about the physical characteristics of the container: "1" identifies this container as a drum; "A" lets you know that it is made of steel. The next number will be a "1" if it is a closed head drum or a "2" if it is an open head drum.

The next series of markings describe what substance the container is capable of holding. The first letter will be an "X," "Y" or "Z." These letters refer to the DOT-designated Packing Group of the product being shipped. These Packing Groups differentiate the inherent hazards of the material being shipped. Packing Group I materials presents a high degree of hazard during transit; Packing Group II materials present a moderate hazard; and Packing Group III materials present the least degree of hazard. An "X" rated drum is capable of holding materials in all three Packing Groups. A "Y" rated drum is suitable for Packing Groups II and III; and a "Z" rated container is only rated for shipment of Packing Group III materials. You can determine which Packing Group applies by using the Hazardous Materials Table found at 49 CFR 172.101.

After the "X," "Y" or "Z," there will be a number. If the drum is rated for shipment of liquids, this number will be small, and usually contain a decimal. This number refers to the maximum specific gravity of the liquid being shipped. In the sample shown above, the drum is rated for liquids with a specific gravity of 1.5 or less. Information on a liquid's specific gravity can be found on a Material Safety Data Sheet (MSDS) for the product or by conducting a laboratory test. If the drum is rated for solids, the number listed is the maximum weight that the drum plus its contents can weigh, in kilograms. In the example shown above, the drum plus its contents cannot exceed 430 kilograms.

The third part of the marking tells you a little bit more about the container's capabilities. If the container is rated for liquids, the number that follows is the hydrostatic test pressure the container can withstand, in kilograms. If the container is for solids, an "S" follows the weight rating. Some drums are dual rated, meaning that they are capable of holding either liquids or solids. If this is the case, both markings will be stamped on the drum. You may notice other markings following the ones listed above. These markings contain other information, such as the drum manufacturer's identification number and the year the container was made.

Another problem with reusing drums is that they often get damaged during shipment or rust while in storage at a facility. Under DOT regulations, drums used to ship hazardous waste must be in good condition, because if the structural integrity of a drum is compromised, it could cause a release of the contents during shipment. Yet another consideration is labeling. Before a drum can be used to store or ship a waste, any references to the original contents of the container must be removed, so that whatever is being put into the drum will not be confused with the previous contents.

Once you have determined that the drum is suitable for the waste you are putting in it, there are still other considerations. Before you ship a drum of hazardous waste, you must make sure that it is closed properly. Drum vendors can supply you with closure instructions specific to your drum. These instructions explain exactly how to close your drum, and to what torque the fittings need to be closed to in order to have the drum properly closed for shipping.

Unfortunately, in the context of storing and shipping hazardous wastes, perception can be substituted for reality. Drums are a case in point. Too often, depictions of mismanaged hazardous wastes include, or are entirely composed of, drums, making it seem that drums are a problem and synonymous with waste. The fact is the steel drum is only a container. And as a container, it provides a reliable method of storage and transport of a wide variety of materials.

Knowing and understanding shipping and handling requirements puts you in an excellent position to meet the expectations of various regulations. And, as containers, steel drums improve your ability to meet those expectations.

This article originally appeared in the 02/01/2002 issue of Environmental Protection.