All chemical waste must be collected in containers that are appropriate for the waste that they contain and must be able to be properly closed. Examples of suitable waste containers include 4-liter or 1-liter glass jars, 20-liter carboys (Figure 8.6), and buckets (Figure 8.7). Examples of unsuitable waste containers include beakers, Erlenmeyer flasks, food grade containers such as milk jugs, or bags for liquid wastes. The department/lab that generates the waste is responsible for providing most waste containers. It is recommended that chemical containers used in the work area be reused for waste collection when they are empty. However, the UMN UMarket offers a variety of containers for purchase. Additionally, HSRM can provide some one-time use containers such as 5-gallon buckets free of charge (Figure 8.7).

When selecting a waste container, make sure that the container is the appropriate type and size for the waste being added. For applications that generate high volumes of waste, a 20-liter carboy or bucket should be considered. If the application does not generate much volume, use a smaller container such as a 1-liter or 4-liter container. 

Make sure that the container is compatible with the waste being added. For example, do not put corrosive waste into a metal container. When containers are reused for waste collection, thoroughly rinse the container before putting a different type of waste to avoid chemical reactions and potential over-pressurization of the waste container. 

Do not put incompatible chemicals in the same waste container. Examples of chemicals that should not be placed into the same waste container include acids with bases, organic solvents with oxidizers (mixing nitric acid into flammable liquid waste containers has caused several incidents in the past), acids with toxics, or reactive chemicals with water. If possible, avoid mixing aqueous waste with organic waste such as flammable liquids. Collect all highly toxic, reactive, mercury, and any exotic wastes (e.g., dioxin compounds, PCBs, controlled substances, pesticides) separately even if they are chemically compatible with other waste streams. Mixing these types of wastes with common waste streams such as organic solvents can result in costly disposal fees. For example, mixing mercury with organic solvent waste means that the entire waste stream must be treated as mercury waste, which is 5 times more expensive. 

If requested, reusable chemical waste containers such as 20-liter carboys or safety cans may be returned to the generator's area for reuse. Clearly mark the container with the building and room number as illustrated in Figure 8.8. Containers unsuitable for reuse will be properly disposed of and not returned. Reusable waste containers should not be used for mercury or mercury compounds, highly toxic, or reactive waste streams. They should only be used for common waste streams such as organic solvents and aqueous solutions. Please contact HSRM for more information regarding chemical waste containers (612) 626-1604 or [email protected].

Empty Containers

Empty chemical containers that are not grossly contaminated should be triple rinsed, the label defaced or destroyed, and may be disposed of in the trash or recycled. Any rinse waste should be collected as hazardous waste. While it is good practice to rinse all chemical containers once they are empty, any empty containers the held constituents found in Appendix A (P-listed acutely toxic chemicals) are required by law to be triple rinsed. For detailed procedures on disposal of empty glassware, visit the Facilities Management Recycling and Waste Reduction webpage.

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