Hazardous Waste: Where on Earth Should it Go?
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By Denise Stockman with contributions from members of the AIC Committee on Sustainable Conservation Practice.
This article was originally published in Vol. 38 No. 2 of AIC News, March 2013, pg. 12-15.
- 1 Introduction
- 2 Identifying Your Hazardous Waste
- 3 What is Your Responsibility?
- 4 Minimizing Waste
- 5 Hazardous Waste Disposal Contractor
- 6 Resources for Finding an Environmentally Sound Contractor
- 7 Questions for a Hazardous Waste Transporter
- 8 Questions for Treatment & Disposal Facility
- 9 Suggestions for the Contract
- 10 In Conclusion
- 11 Acknowledgements
- 12 References
The Committee on Sustainable Conservation Practice conducted two surveys in the last four years, partially to ascertain environmental topics that conservators would like more information about. The subject of solvent disposal was a top choice in the surveys both years.
The Health and Safety Committee gave an excellent overview of the regulations concerning solvent disposal and other hazardous waste in their “Cradle to Grave” article and wiki entry. It addressed the following issues:
- Regulations governing hazardous waste and general variations state-by-state
- Identifying hazardous waste
- Usage suggestions
- Chemical compatibilities
- Removal of waste from your site
- Unacceptable disposal procedures
Instead of revisiting all of the information covered by H&S, this article will examine what happens to used solvents in the United States and consider the question: How can you be as environmentally responsible as possible in disposing of hazardous waste?
Identifying Your Hazardous Waste
The “Cradle to Grave” article describes in-depth the four Environmental Protection Agency (EPA) categories of hazardous waste: Ignitable, Corrosive, Reactive, or Toxic. It is important to know the chemical characteristics of the materials you use and read the MSDS (soon to be GHS, see the July 2012 AIC newsletter ) to determine whether it will fall into one of these categories. See table below.
Please note: Although it may be tempting to dilute or otherwise “treat” waste so that it no longer meets the definition of hazardous, it is illegal to do so without an EPA permit.
|Used Organic Solvents||Yes||
|Alcohols mixed with water||Depends|| An alcohol/water mixture is considered hazardous waste if it has a flash point below 140 degrees F or is greater than 24% alcohol by volume (EPA: Characteristic Hazardous Waste)
|Adhesives||Use your best judgment|| The EPA does not automatically consider a solvent to be hazardous waste when it is considered an ingredient in a mixture. But, if it has a flashpoint is below 140 degrees F, it is hazardous waste.
|Poultices with solvent||Yes|| The EPA does consider a solvent to be hazardous waste when it has been used to dissolve or clean something.
|Acids and bases||Depends|| Acids and bases can be neutralized. Liquids within the pH range of 2 and 12.5 can be poured down the drain – national regulations. Some cities have stricter regulations.
|Hydrogen peroxide (H2O2)||Maybe|| At concentrations below 8%, you can legally pour down the drain. If you want to do what is best for the environment, dispose of all H2O2 through a hazardous waste contractor, but read the MSDS to avoid incompatibilities when storing with other hazardous waste awaiting pick-up.
|Sodium borohydride and other bleaches||Most likely|| Check with your local water authority and describe the amounts and concentrations.
|Pigments||Depends|| Does it meet the definition of ignitable, corrosive, reactive, or toxic? Toxic pigments include cadmium and cobalt.
|Gloves, swabs, cotton, and other disposable tools and equipment laden with solvent||Depends|| Does it meet the definition of ignitable, corrosive, reactive, or toxic?
|Surfactants||Depends|| Does it meet the definition of ignitable,corrosive, reactive, or toxic?
* (References for table: ; McCann 2005)
What is Your Responsibility?
Most conservation labs are considered by the EPA to be “Very Small QuantityGenerators” (VSQG) or “Conditionally Exempt Small Quantity Generators”(CESQG) of hazardous waste. These definitions were created under the ResourceConservation and Recovery Act (RCRA) Subtitle C. 
VSQGs and CESQGs are required to: 1. Identify and separate out hazardous waste into the proper containers for disposal. 2. Generate less than 220 lbs of non-acutely hazardous waste per month. (In contrast, the limit for “acutely hazardous waste,” i.e. extremely toxic or explosive materials, is just over 2 lbs.) 3. Not store more than 2,200 lbs. (More than these amounts requires an EPA ID number.) 4. Ensure delivery of the waste to an off-site treatment or disposal facility with the proper permits.
It is not acceptable, nor legal, in accordance with RCRA, to off-gas solvents into the fume hood. This creates volatile organic compound (VOC) emissions, which lead to ground-level ozone (smog) upon reacting with light and heat. At high enough concentrations as a vapor, flammability is a concern.  Many conservation laboratories carry out this practice and it is not environmentally sound.
It is not legal to pour solvents into the sink for several reasons. It may also violate local sanitary sewer authority regulations. Solvents can corrode the plumbing as they drain. They will collect in the trap and release fumes back up through the drain, and they can pollute local groundwater or water bodies.
Polluting groundwater and water bodies must be avoided. Waste water empties either to a septic system or a municipal sewer system. In the case of a septic system, the water travels into a tank buried underground. The liquids and solids in the tank are broken down by bacteria, then filter out through a network of pipes into a drain field where it continues to be treated through natural processes in the soil. Solvents can kill the bacteria in the tank or the ground and reduce the effectiveness of the system. Bioremediation is then needed to get it working properly again.
For most conservation labs, waste water is piped to a municipal sewage plant and treated. Municipal sewage treatment is much more complicated and varied, but is also likely to rely on bacteria to treat the water as part of the process. Most systems do not treat laboratory solvents and other hazardous waste because to do so requires specialized treatment; the law requires disposal in accordance with RCRA regulations.
It is not legal or acceptable to place hazardous waste into the regular trash. You may cause harm to others who encounter it during transport to landfill. Many landfills leak. They are not intended for hazardous waste.
The best way to comply with the law and protect the environment is to work with a hazardous waste disposal contractor. The EPA sets no specific limit for how long you can store hazardous waste on-site as a CESQG, but some local laws may be more stringent. A good rule of thumb is to arrange for pick-up of the waste about once a year. Ideally, liquid and solid wastes should be stored in labeled, well-sealedcontainers that are isolated in a tray to catch leaks. For more on containerization, see the “Cradle to Grave” article
Extremely small businesses working out of a home and generating very small amounts of waste may be able to take properly containerized and labeled waste to a household hazardous waste collection center. It is important to check with state or local environmental agencies to see what the regulations are. Links to State Environmental Agencies Some materials exchange sites allow particular types of hazardous waste, so check the listings. Materials Exchange Chemical manufacturers may be able to use old solvent if it is valuable enough to offset the cost of transport. Again, their ability to do this depends on state and local regulations.
The following procedures can help to reduce solvent use:
- Don’t buy more solvent than you need. This can be difficult, as some suppliers sell in large amounts, but it helps to compare what several different suppliers can offer.
- If there are multiple laboratories in your organization, have one person order and keep track of all the solvents to reduce overbuying.
- Keep good notes about what works to avoid trial-and-error in the future.
- Keep your calculations handy so that you can easily mix up a small batch of a solvent mixture in the future, rather than relying on an easy, but larger, measurement such as 100 mL each time.
- Read through suggestions in specialty group sections of the AIC Wiki to find the most effective and least wasteful treatment procedure. For example, “Hinge, Tape, and Adhesive Removal” provides information about the specific adhesives found in different products and suggests non-solvent techniques for reducing them.
- Improve solvent storage to reduce or eliminate evaporation.
- Reinforce cap seams by wrapping with paraffin wax or plastic wrap.
- Do not leave solvent containers open during use. Self-closing solvent dispensers minimize evaporation.
- Whenever possible, pour from small containers, reducing spills and evaporation in the transfer.
- Clean brushes in used solvent rather than new solvent.
Hazardous Waste Disposal Contractor
Among the reasons for hiring a waste disposal contractor are to comply with RCRA—including proper record-keeping—and to protect your employees and the environment from harm. Anyone transporting hazardous waste must have an EPA identification number.  Processing and disposal facilities are prohibited from accepting waste from an unauthorized transporter. A few states, such as Minnesota, allow a VSQG to get a permit, but most do not.
The HW disposal contractor’s transporter will take the waste to a treatment facility. This may be owned and operated by the same company, but is in most cases a different entity. “Treatment” is an umbrella term that includes any process that alters the waste to make it nonhazardous. The possible treatments from most to least desirable are:
- Reuse: finding a new use for the waste, perhaps as a feedstock for an industrial manufacturer.
- Recycling, Reclamation, or Recovery: processing the waste back to a usable product.
- Incineration: combusting the waste to turn it into energy while breaking it down. One use is to heat Portland cement kilns, which require extremely high temperatures.
- Pyrolysis: using an ultra high temperature electric arc to neutralize persistent organic pollutants.
- Placing liquid waste into underground injection wells or storage tanks.
- Fixation or solidification: mixing the waste with materials such as fly ash and cement dust inside clay cells to form solid matter that can be safely put into land fill.The waste is more likely to be put to one of the more environmentally desirable uses if it is well-labeled. Good labeling may also save you money.
Resources for Finding an Environmentally Sound Contractor
- The websites of many state environmental agencies have listings of local transporters. Link to State Environmental Agencies
- Ask your local colleagues in conservation and other small businesses that are CESQG’s--such as dental offices, print shops, and photo processors--for a recommendation.
- Check the transporter’s safety record on the Department of Transportation website. 
- Other websites with company listings: ; 
Questions for a Hazardous Waste Transporter
- Do you have the proper permits and ID number? (The federal permit is known as an RCRA Permit.)
- How long have you been in business?
- Do you have adequate insurance for the transportation and storage of these materials?
- Does the waste go to a facility owned by you or owned by another company? Which company?
- Do you take care of all the legally required paperwork and licensing?
- What kind of support do you provide for emergency spill situations?
- Is some of the work done by contractors? If so, which tasks?
- Who are the subcontractors?
- What do you expect from me as a generator?
- Do you have a minimum requirement for pick up?
- Can you provide references from other customers in businesses similar to mine?
- What are all the costs? Are there fees for: Hauling (sometimes called a stop charge)? Disposal? Drum replacement? Anything else? Is there an extra charge for fluid containing a large quantity of water?
- Are there any recycling credits for waste that has been turned into a usable product?
Questions for Treatment & Disposal Facility
In addition to the first 3 questions above:
- Can I visit the facility?
- How often and under what circumstances are you able to reuse or recycle used solvent?
Suggestions for the Contract
- The contractor will take care of necessary disposal paperwork.
- The contractor will notify the relevant regulatory agencies in the event of a spill during transport.
- The contractor will furnish all of the equipment necessary for disposal,storage, and transportation including labels, and will also dispose of used storage and handling materials.
- The contractor will allow representatives from the business to perform inspections or audits when requested.
- The contractor will make arrangements to pick up hazardous waste upon request within a reasonable time.
- The contractor will give information on disposal method used upon request.
- The contractor will respond immediately with disposal assistance in an emergency situation.
- The contractor will disclose any current enforcement actions involving the contractor by the EPA or state or local agency.
There are several resources to consider. Start with state and local environmental agency websites. Don’t be afraid to contact them and ask questions. Hazardous waste transporters are also a great resource. They want your business and willhave experts ready to take calls and answer questions.
The best solution for each situation requires some research and consideration. Like many environmental solutions, doing the research takes some effort, but will pay off with confidence that the best possible actions will minimize impact on human health and the environment, and will comply with the law.
Thanks to Jim Stratton at the Smithsonian Office of Safety, Health and Environmental Management; Tom Baker and Mike Richter at Veolia Environmental Services Technical Solutions; Lisa, Amanda and Beth at Shamrock Environmental Corporation; Michael Lee at Etherington Conservation Services; Tom Braun at the Minnesota Historical Society; and the members of the AIC Health & Safety Committee and the Committee on Sustainable Conservation Practice.
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