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Section 5 - Waste Requiring Special Processing
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Circuit Boards and Computer Monitors
Compressed Gas Containers/Aerosol Cans
Compressed Gas Cylinders
Disposable Propane and Butane Containers Aerosol Cans
Aerosol Cans
Transfer Documentation
How to Responsibly Dispose of Electronic Waste at the U
Aqueous Solutions of Ethidium Bromide or Cesium Chloride / Ethidium Bromide
Acrylamide and Agarose Gels Containing Ethidium Bromide
Alcohol Solutions of Ethidium Bromide
Labware Contaminated with Ethidium Bromide
Spills of Ethidium Bromide
Lunn and Sansone Ethidium Bromide Destruction Method
Armour Ethidium Bromide Destruction Method
Lunn and Sansone Method for the Decontamination of Equipment Contaminated with Ethidium Bromide
Fluorescent, High Intensity Discharge (HID), and UV Germicidal Lamps
Chemicals Mixed with Radioactive and/or Biological Materials
Storage Procedures
Testing Procedures
Peroxide Inhibitor
Warning Label
Emergency Disposal
Battery Collection
The Minnesota Pollution Control Agency and the seven metro area counties prohibit the disposal of waste batteries in the trash. Batteries must be disposed of as either hazardous waste or industrial solid waste.
If you have any questions about battery collection or battery pick-up, please call (612) 626-1604.
Dry Cell and Button Batteries
All batteries require special collection and processing because of their heavy metal content. Alkaline and carbon zinc batteries from businesses are not allowed to go into solid waste streams which will be incinerated.
To request a waste battery collection container, call the Chemical Waste Program at (612) 626-1604.
The container comes labeled with instructions and includes a waste packing form. When you send in the form, indicate that you will need a replacement container. Collection and replacement should occur within 10 days of the time you send in the form. A copy of the battery container label is included in this Guidebook (see Appendix XI). If you are not using one of the pre-labeled containers, attach a copy of this label to the container you are using.
If you know the specific type of battery, use that information to complete the waste packing form. For mixed batteries, use the "mixed dry cell batteries" information to complete the form:
| DDC | CAS | COMPOUND NAME | EPA# |
| 05SO | UOFM1637A | ALKALINE BATTERIES | NONE |
| 09WS | UOFM1692A | LITHIUM BATTERIES | D003 |
| 18SP | UOFM1569A | MERCURY OXIDE BATTERIES | D009 |
| 18HM | UOFM1593A | SILVER OXIDE BATTERIES | D011 |
| 18HM | UOFM1585A | NICKEL-CADMIUM BATTERIES | D006 |
| 18HM | UOFM2220A | LEAD ACID GEL CELL BATT. | NONE |
| 05SO | UOFM1638A | ZINC-CARBON BATTERIES | NONE |
| 05SO | UOFM1584A | MIXED DRY CELL BATTERIES | D009 |
Lead Acid Batteries
Lead-acid batteries (automotive batteries) must be stored in a curbed, impermeable-surface storage area. Secondary containment trays are available through University Stores, (612) 624-4878, part no. CX18999. Prior to collection by the Chemical Waste Program, these batteries should be individually packaged upright in a sturdy plastic-lined box.
Use the following codes for lead acid batteries on the waste packing form:
| DDC | CAS | COMPOUND NAME | EPA# |
| 18HM | UOFM2220A | LEAD ACID BATTERIES | NONE |
Circuit Boards & Computer Monitors
Printed circuit boards and circuit board scrap removed from electronic equipment must be collected and managed as a special hazardous waste due to leachable metals, such as lead, in their solders. Discarded cathode ray tubes (CRT) monitors are also considered to be a special hazardous waste due to their content of leachable metals. The University will collect the circuit boards and monitors as part of the Chemical Waste Program and send the material to a licensed recycler for metal recovery.
Circuit Boards
Printed circuit boards should be disposed of according to the following procedures:
- Collect the circuit boards and scrap in a sturdy box, plastic pail, or drum. Clearly label the collection container "Printed Circuit Boards for Reclamation." Yellow hazardous waste labels should not be put on the circuit boards or the collection boxes, pails, or drums. Drums can be obtained from the Chemical Waste Program by calling (612) 624-8855 or (612) 624-6060.
- Use the University waste packing form to request pick-up of your circuit board containers when they are full.
Computer or Cathode Ray Tube Monitors
Computer or CRT monitors should be disposed of according to the following procedures:
- Monitors should be boxed in their original boxes if possible to avoid breakage in transport. The box should be clearly labeled "Monitor for Reclamation." Yellow hazardous waste labels should not be put on the monitors or boxes.
- If the monitor does not work, put a piece of tape on the monitor, with the words "Does Not Work" on it, other wise mark the tape with the word "Works." This will aid our recycling staff in routing working monitors to University departments that can use them.
- Use the University waste packing form to request pick-up of the circuit boards or monitors.
Compressed Gas Containers/Aerosol Cans
Due to lack of disposal options and outlets for waste gas cylinders, disposal of these items presents a special problem for the Chemical Waste Program. The few disposal companies which accept gas cylinders generally require certification that the cylinders are equipped with working valves and the contents of the cylinders are known.
The Chemical Waste Program has two possible disposal options - a disposal company may:
- vent the cylinder into a chemical waste incinerator or into the flow of another chemical treatment process; or
- recapture the cylinder contents and recycle the gas.
Both of these options cost from $300 to $10,000 per cylinder depending on size and contents. Therefore, all purchase orders for new cylinders must state that the vendor will accept the return of the empty or partially empty cylinder from the University.
It is very important that users of gas cylinders prevent damage to the cylinders and valves and keep the cylinders properly labeled as to their contents. It is very expensive to analyze an unknown cylinder and even more expensive to transfer the contents of a damaged cylinder into a DOT approved cylinder.
Arrangements should be made at the time of purchase for return of the cylinders.
Compressed Gas Cylinders
Compressed gas cylinders should be submitted for collection according to the following procedures:
- Return gas cylinders, whether empty or partially filled, to the manufacturer or distributor through which they were purchased. If the manufacturer will not accept the cylinders for disposal, they should be purchased through another supplier. If originally purchased through the University storehouse, contact the University Stores at (612) 624-2094 to make arrangements for return of gas cylinders.
- Use up all of the gas in a cylinder to render it empty if at all possible. Empty cylinders should be clearly marked as empty to avoid confusion when it comes to return or disposal of the cylinder. Do not vent full or partially used cylinders into fume hoods as a means of disposal.
- In the event it is not possible to return the cylinders as specified above, submit the cylinders for waste pickup by the Chemical Waste Program following normal disposal procedures. Make sure the cylinders are clearly marked as to contents and valves are properly sealed and capped.
Disposable Propane and Butane Containers
Empty disposable propane and butane bottles should be submitted for waste collection by the Chemical Waste Program in accordance with normal University hazardous waste disposal procedures.
Aerosol Cans
Dispose of aerosol cans according to the following procedures:
- Chemical products in aerosol cans should be used up in their intended manner whenever possible. When aerosol cans are empty (at atmospheric pressure), they may be disposed of in the trash.
- If the aerosol can is not empty, submit for waste collection by the Chemical Waste Program. Note that in packaging, the cans should stand upright in the box and be capped to prevent the release of contents. If the ingredients of the can are known, list them on the waste form with the respective percent composition. If a commercial product, list company name, location and any hazard information listed on the can.
Controlled Substances
Substances registered with the Drug Enforcement Agency (DEA) should be sent to the Chemical Waste Program for proper disposal. A list of the controlled substances most commonly found in research and clinical labs at the University are listed in this Guidebook (see Table 5-1 below ).
All registrants transferring controlled substances must complete a Controlled Substance Disposal Form. One Controlled Substance Disposal Form should be prepared for each package of substances submitted for transfer. It is important to include the DEA Registrant number. If you do not have one, indicate "unknown" or "abandoned" in the box. Include your department. building and room number in the "From" section. Mail or fax one copy of the completed Controlled Substance Disposal Form to DEHS. The mailing address is:
University of Minnesota - TCEM
501 23rd Ave SE
Minneapolis, MN 55455
Attn. Jon Wentworth
Fax: 612-626-1571
Retain one copy of Controlled Substance Disposal Form for your records. DEHS will schedule a transfer of the substances. DEHS will complete a Form 222 for Schedule II substances submitted for transfer.
Prior to shipment, the authorized transporter (DEHS staff) will verify the contents of the package with the Controlled Substance Disposal Form. Both the registrant and transporter will sign and date the Controlled Substance Disposal Form. A copy of the document with two signatures will be left with the registrant. The controlled substances will be transported to the University's Thompson Center for Environmental Management (TCEM). The authorized receiver will accept the package and verify the contents with the Controlled Substance Disposal Form. The receiver will sign and date the Controlled Substance Disposal Form. A copy of the Controlled Substance Disposal Form with 3 signatures will be sent to the registrant as a record of receipt. Retain this for your records.
Transfer Documentation
Researchers who have excess controlled substances in syringes after a research procedure are required to collect the excess in a slurry bottle and document the contents of the slurry bottle on a Controlled Substance Disposal Form. Use the same procedure as above to initiate collection.
In order to obtain a slurry bottle, contact Hazardous Waste 612-626-1604 or hazwaste@umn.edu. Indicate your location and Campus Mail address.
Table 5-1 Typical Controlled Substances
| Amobarbital | Ketamine | Pentobarbital |
| Amphetamine | Mescaline | Phenobarbital |
| Barbital | Methadone | Sodium Amytal |
| Butethal | Methamphetamine | Sodium Barbital |
| Chloral Hydrate | Methaqualone | Sodium Secobarbital |
| Cocaine | Morphine | Tetracaine |
| Codeine | Morphine Sulfate | Tetrahydrocannabinol (THC) |
| Diazepam | PCP | Thiobarbituric Acid |
| Heroin |
How to Responsibly Dispose of Electronic Waste at the U
Why recycle?
In the past two decades, hundreds of millions computer sets in the United States have been tucked into warehouses and residential basements and attics. Contained in those computers are roughly 650 million pounds of lead, 987,000 pounds of cadmium, 231,000 pounds of mercury, and more than 2 billion pounds of plastics.
Most computer users are unaware of the toxic contents of their PCs. A standard display monitor contains from 4 to 8 pounds of lead, which lines the glass cathode ray tube, or CRT, as a user shield against radiation. There is less lead in a Liquid Crystal Display (LCD), but the latter typically contain mercury in the fluorescent lamps used for backlighting.
Minute amounts of mercury, a highly toxic and environmentally persistent metal, appear in the computer's printed wiring boards, switches, relays, and batteries. Cadmium compounds, metals suspected as persistent carcinogens, appear in a computer's batteries, wiring boards, and plastic stabilizers. And plastics, the computers No.1 ingredient, are pesky: They typically have little value yet require difficult separation for an expensive recycling process that is itself toxic.
It's the law
Disposal of electronics is against the law. Unwanted electronics containing printed circuit boards and cathode ray tubes, (e.g., computer monitors), are considered hazardous waste by the state of Minnesota if not managed for recycling, reuse, reclamation, or demanufacture.
What is electronic waste?
It may surprise you to know that the following items are all considered hazardous electronic waste:
- Computer monitors and computers
- Televisions
- Photocopiers
- Fax machines
- Electric typewriters
- Calculators
- Laboratory equipment
- Video monitors
- Telephones and telecommunications equipment
- Audio Equipment
Your Options
So, what can you do to get rid of your old equipment? The following options are available through the University of Minnesota:
- University Computer Services (UCS) will pick up your computer products—CPU, monitor, keyboard, mouse, and other hardware—free of charge. The computers are checked for quality, sanitized to University standards and designated for resale through their program or sent for proper recycling through the University Recycling Program. UCS sells used computers to the University community and the public. Visit http://www1.umn.edu/ucs/pickup.php for more information. Call UCS at 612-624-4800 to schedule a pickup or appointment.
- The University Recycling Program (612-625-6481) will arrange to collect non-computer electronic waste and is free of charge. They maintain a Reuse Program/Virtual Warehouse at http://www1.umn.edu/recycle/reuse.html to distribute non-computer electronics and other items back into the University community; call them to have pictures of your equpment posted to the Web. Electronics not suitable for use are sent to the University’s electronics recycling contractor. They will also collect “mixed loads” containing both computer and non-computer electronics.
- The Minnesota Technical Assistance Program (MnTap) provides an exchange of equipment no longer usable by one party, but usable by another. Contact MnTap at 612-624-1300.
Waste Prevention
To help prevent electronic waste, ask yourself the following questions before buying new equipment:
- Can old equipment be repaired or upgraded?
- Is this new equipment truly necessary? If so, consider purchasing equipment that is easy to repair or recycle.
- Is equipment available that has been refurbished or contains recycled materials?
- Can old equipment be traded in for new?
- Can new equipment be leased instead of purchased?
Questions? Concerns?
If you still have questions, or are not sure which is your best option, contact Gene Christenson, chemical waste manager, at 612-626-1590 or via e-mail at chris067@umn.edu. He’ll help you locate the best option for disposing of your electronic waste.
Ethidium Bromide
Ethidium bromide (EtBr) is a powerful mutagen widely used in biochemical research laboratories for visualizing nucleic acids. The compound forms fluorescent complexes by intercalation and these compounds are readily visible under ultraviolet (UV) light. EtBr is generally used in the laboratory dissolved in water or buffer solutions.
Since EtBr is so widely used, proper management of EtBr containing waste and EtBr contaminated materials is important. Below are the procedures to be followed for EtBr containing waste and EtBr contaminated materials:
Aqueous Solutions of Ethidium Bromide or Cesium Chloride/Ethidium Bromide
Aqueous solutions of less than 10 mg/L EtBr may be disposed of in the sanitary sewer.
Aqueous solutions of more than 10 mg/L EtBr must first be treated before they are disposed of in the sanitary sewer or they may be sent to the Chemical Waste Program. Aqueous solutions can be deactivated by either the Lunn and Sansone method (shown below) or the Armour method (shown below) and then disposed of in the sanitary sewer. The Lunn and Sansone method degrades EtBr by reaction with sodium nitrite and hypophosphorous acid in aqueous solution. The Armour method degrades EtBr with household bleach.
Alternatively, the solution can be filtered through an EtBr filter. While wearing proper protective equipment, the paper carbon filter disk containing EtBr must be removed from the filter using a forceps and then processed through the University of Minnesota Chemical Waste Program. The remaining polypropylene filter unit can be rinsed with bleach, and disposed of as solid waste.
Note: Waste solutions greater than 10 mg/L must not be diluted and then disposed of by sewer under this policy. Dilution as a partial or complete substitute for pretreatment before discharge in a public sewer is prohibited by the Metropolitan Council Environmental Services (Waste Discharge Rules for the Metropolitan Disposal System, Article IV, Section 404.00).
Acrylamide and Agarose Gels Containing Ethidium Bromide
Acrylamide and agarose gels containing less than 10 mg/L EtBr can be disposed of in the trash. Gels that are trashed should be put in double lined trash bags and labeled as nonhazardous.
Acrylamide and agarose gels containing more than 10 mg/L EtBr must be processed through the University of Minnesota Chemical Waste Program.
Alcohol Solutions of Ethidium Bromide
Because alcohols are flammable, all alcohol solutions containing EtBr should be processed as hazardous waste through the University of Minnesota Chemical Waste Program.
Labware Contaminated with Ethidium Bromide
Contaminated labware includes needles, disposable gloves, pipettes, test tubes, etc. that are contaminated with EtBr. Depending on the type of waste that you generate, follow the procedures below.
- Needles, scalpels, Pasteur pipettes and other sharps contaminated with EtBr should be disposed of directly into a sharps container.
- Volumetric or transfer pipettes, and other disposable glassware contaminated with EtBr should be disposed of in a waste container designated for glass disposal. Grossly contaminated (visibly contaminated) glassware should be washed with bleach before disposal in the designated container.
- Test tubes and centrifuge tubes contaminated with EtBr should first be emptied, with the liquid disposed of according to the procedures given above. Empty tubes can then be disposed of in the trash. Grossly contaminated (visibly contaminated) tubes should be washed with bleach prior to disposal.
- Laboratory equipment (e.g. transilluminators, laboratory floors and countertops, etc.) contaminated with aqueous solutions of more than 10 mg/L EtBr should be decontaminated using the Lunn and Sansone method for decontamination of equipment contaminated with EtBr. (Shown below) This is done by scrubbing the contaminated lab equipment with paper towels soaked in a freshly prepared aqueous solution of sodium nitrite and hypophosphorous acid while wearing the proper protective equipment. The towels are then decontaminated in the decontamination solution before disposal in the trash.
- Most other disposable labware (e.g. sample vials, disposable beakers, etc.) contaminated with EtBr may be disposed of in the normal trash. Grossly contaminated (visibly contaminated) disposable labware should be washed with bleach prior to disposal.
Spills of Ethidium Bromide
Small spills (less than 0.5 L) of aqueous solutions of more than 10 mg/L EtBr and the resulting contaminated lab equipment can be decontaminated using the Lunn and Sansone method (shown below) for decontamination of equipment contaminated with EtBr. The EtBr is degraded by wiping the surface with paper towels soaked in a freshly prepared decontamination solution (an aqueous solution of sodium nitrite and hypophosphorous acid) while wearing the proper protective equipment.
All spills containing Ethidium Bromide should be reported to EHS at (612) 626-6002.
Lunn and Sansone Ethidium Bromide Destruction Method
(Lunn, George, and Sansone, Eric B. 1994. Destruction of Hazardous Chemicals in the Laboratory. John Wiley and Sons, Inc. pp. 185.)
- Carry out the following steps in a fume hood and follow all laboratory safety precautions, including proper protective clothing.
- Dilute solutions containing EtBr to concentration <0.05% w/v (50mg/100mL).
- For each 100mL of EtBr solution add 20mL of fresh 5% hypophosphorous acid and 12mL of fresh 0.5M sodium nitrite solution. Check that the pH of the solution is <3.0. Stir briefly.
- After reacting for at least 20 hours, neutralize with sodium bicarbonate, then rinse the solution down the sanitary sewer with water.
Armour Ethidium Bromide Destruction Method
(Armour, Margaret-Ann. 1994. Personal communication.)
(Kaufman, James A. ed. 1990. Waste Disposal in Academic Institutions.
Lewis Publishers. pp. 127-8)
- Carry out the following steps in a fume hood and follow all laboratory safety precautions, including proper protective clothing.
- Dilute solutions containing EtBr to concentration <0.034% w/v (34mg/100mL).
- Add 10mL of fresh bleach for every 1mg EtBr.
- Stir at room temperature for at least 4 hours.
- The EtBr is converted to the physiologically inactive product 2-carboxybenzophenone, and the solution should then be rinsed down the sanitary sewer with water.
Lunn and Sansone Method for the Decontamination of Equipment Contaminated with Ethidium Bromide
(Lunn, George, and Sansone, Eric B. 1994. Destruction of Hazardous Chemicals in the Laboratory. John Wiley and Sons, Inc. pp. 186.)
- Before decontamination, deenergize all electrical equipment and wear the appropriate protective equipment.
- The decontamination solution is prepared by adding 20mL of 50% hypophosphorous acid to a solution of 2g of sodium nitrite in 300mL of water.
- Scrub the contaminated surface or equipment with a paper towel soaked in the freshly prepared decontamination solution. Scrub another five times with paper towels soaked in the freshly prepared decontamination solution, using a fresh towel each time.
- Place all the used towels in a large container and soak them in fresh decontamination solution for at least one hour.
- Neutralize used decontamination solution and towels with sodium bicarbonate. The towels can then be discarded in the trash, and the solution may be rinsed down the sanitary sewer with water.
Note: A small amount of nitrogen dioxide may be given off when the decontamination solution is initially mixed, so the procedure should be carried out in a chemical fume hood.
Fluorescent, High Intensity Discharge (HID), and UV Germicidal Lamps
Fluorescent, high intensity discharge (HID), and UV germicidal lamps are considered a hazardous waste and must be collected intact for proper disposal or recycling. The University of Minnesota recycles these lamps to provide raw materials for new products and, most importantly, to prevent mercury from contaminating the environment.
Procedures
Fluorescent, high intensity discharge (HID), and UV germicidal lamps must be collected in containers that protect the lamps during collection and transportation. The original shipping container is the preferred collection package for spent lamps. Remove any cardboard end pieces to assure that lamps fit in the box. Do not put the individual lamp sleeves on the spent lamps. The Chemical Waste Program also has boxes available for packaging standard 4 foot and 8 foot length fluorescent lamps. To receive a packing box, call the Chemical Waste Program at (612) 626-1604.
Shorter lamps can be packaged with the 4 and 8 footers, if packed as to prevent movement. Otherwise any sturdy box will do for small lamps, mercury vapor lamps and other odd shaped fluorescent tubes. In the case of smaller bulbs, additional packing materials may need to be added to prevent breakage.
Remove sleeves and tape from spent lamps when packing for waste collection. Taping lamps together increases the chance of breakage during the recycling process.
Properly mark the box with the words "Hazardous Waste." The contents, start date, number and size of lamps must be listed on each box.
Facilities Management personnel may choose to post the area in which the bulbs and tubes are collected with the words "Hazardous Waste - collection site for fluorescent, HID and UV germicidal lamps." This method does not require that each box be labeled.
If you happen to break fluorescent, HID, or UV germicidal lamps, collect the broken glass, metal or plastic as a hazardous waste. When fluorescent lamps and HIDs are broken, mercury is released to the environment, but some mercury still remains on the surfaces of the glass, phosphor and the metal or plastic. This debris must be collected as hazardous waste and the container sealed. The container must be properly labeled with the words "Hazardous Waste," the contents listed as "broken fluorescent lamps" with the start date of accumulation.
It costs the University more to have broken lamps processed than intact lamps, but collection of the broken lamps helps keep mercury releases to the environment at a minimum.
Once the box is full, properly packed and sealed, arrange for collection. For locations on the Minneapolis and St. Paul Campuses, call the Facilities Management zone office for your area for collection. If you generate a large number of lamps or are located at an off-campus Twin Cities location, call the Chemical Waste Program at (612) 626-1604 for collection.
Labware
Labware and empty chemical containers may hold residues which are hazardous. Therefore, special precautions must be taken before recycling these items.
Procedures
Empty chemical containers which did not contain pesticides, toxic, or acutely toxic (P-list EPA waste code, found in the Registry, see Appendix I) chemicals may be disposed in the trash. Empty glass bottles and broken laboratory equipment should be rinsed to remove residual chemicals, air dried, placed in a separate outer container (e.g. cardboard box or plastic pail) and labeled as "nonhazardous waste containing (broken) glass."
Laboratories may recycle rinsed flint glass containers (not labeled as Pyrex, Kimax, etc.) with the lids or caps removed through the University Recycling Program. For empty solvent bottles intended for recycling, uncap the container, rinse with water, remove labels or mark as "empty," and place it in a fumehood to air dry. Collect any residual solvent from containers as hazardous waste prior to rinsing.
Contact the Chemical Recycling Program at (612) 626-1859 to recycle borosilicate (Pyrex or Kimax) containers and laboratory glassware such as test tubes, flasks, pipets, etc.
Empty bottles which originally contained pesticides or ingredients considered acutely toxic by the U.S. Environmental Protection Agency may be disposed of or recycled after triple rinsing. Acutely toxic chemicals can be identified by an EPA# which begins with "P" listed in the Chemical Waste Registry, (see Appendix I).
Rinse bottles that contained pesticides, heavy metals (except mercury) or acutely toxic chemicals three times with 10% of the bottle volume of an appropriate solvent which is capable of removing the chemical. The rinsate must be collected as hazardous waste. Pesticides rinsates should be land applied when possible per EPA regulations or disposed of as hazardous waste.
If highly toxic residue remains on the labware, contact the Chemical Waste Program to determine the appropriate route of disposal. It may be necessary to dispose of the contaminated labware as hazardous waste. Complete a waste packing form for the contaminated labware. Label as "Labware (or glassware) contaminated with ______" (state name of highly toxic residue). These containers with residues are not acceptable for recycling, but they may be used to collect compatible hazardous waste. These containers must be relabeled appropriately.
Note: The University has two glass recycling programs. The University Recycling Program (612) 625-8084 recycles solid waste such as flint glass containers, but not Pyrex or Kimax glass. The Chemical Recycling Program (612) 626-1859 recycles laboratory chemicals and laboratory glassware.
Mercury Contaminated Labware must be collected as hazardous waste.
Mixed Waste
Chemicals Mixed with Radioactive and/or Biological Materials
Mixed waste is any waste that contains both EPA-regulated chemical waste and radioactive isotopes. These wastes are difficult and costly for the University to dispose of and should be generated only when necessary and in prudent amounts. As hazardous and radioactive wastes are regulated under separate jurisdictions (EPA and NRC respectively), and as the treatment goals are different for each jurisdiction, management of these waste streams can be complicated.
For the generator of mixed waste, the first strategy is minimization and segregation so that the least amount of mixed waste is produced. Refer to Prudent Practices in the Laboratory: Handling and Disposal of Chemicals, National Research Council, 1995, pages 150-160 for techniques to minimize mixed waste generation.
Once generated, mixed waste needs to be reported to and co-managed by both the Chemical Waste and the Radiation Protection Programs. Follow the procedures in the University of Minnesota Manual of Policies and Procedures for Radiation Protection, Section XI. Call the Radiation Protection Program at (612) 626-6002 for copies of the Radiation Protection Manual.
In the Twin Cities, instead of sending in the top copies of the waste packing form, leave all copies on the waste container. Outside the Twin Cities, contact the Radiation Protection Program (612) 625-1682 concerning the waste; then send in the top two copies of the waste packing form to the Chemical Waste Program, 501-23rd Ave. SE, Minneapolis, MN 55455-0447, noting on the form that you have already contacted the Radiation Protection Program about this waste. List the isotope and amount in millicuries on the waste packing form.
Peroxide-Forming Chemicals
Some common laboratory chemicals can form peroxides on exposure to air. Peroxides are shock-sensitive and can be violently explosive in concentrated form or as solids. Others can result in rapid polymerization and can initiate a runaway, explosive reaction. The most commonly used peroxide-forming chemicals are: diethyl ether (ethyl ether), tetrahydrofuran (THF), dioxane. Isopropyl ether (diisopropyl ether) is a severe peroxide hazard. Organic peroxides are another class of compounds with unusual stability problems and as such are one of the most hazardous class of chemicals normally handled in the laboratory. Organic peroxides are listed in the Registry (see Appendix I) with "12" as the first two digits of the DDC number.
Due to the unstable nature of organic peroxides, it is necessary to contact the Chemical Waste Program (612) 626-1604 when discarding these chemicals.
Storage Procedures
The best way to manage chemicals that have the potential for forming shock sensitive peroxides is to purchase only the quantity that is required in a one month period. Store the material in a tightly closed, properly labeled container in a flammable storage cabinet, away from flames, heat, sources of ignition, light, oxidizers and oxidizing acids.
Caution: All peroxidizable compounds should be stored away from heat and light. They should be protected from physical damage and ignition sources.
When peroxide-forming chemicals reach their expiration date, it is recommended that you process the chemicals for waste collection. If peroxide concentrations are greater than 80 ppm, call the Chemical Waste Program at (612) 626-1604 (see Testing Procedure section below).
If a peroxide forming chemical is older than its expiration date or is stored longer than the time limits (see Table 5-2), follow these procedures:
Prior to moving the container, examine it.
- Call the Chemical Waste Program if crystals are visible in the chemical solution or if crystals are on or in the container. Closely examine the container near the cap for the presence of crystals. Some peroxide crystals in solution have a very fine, spun glass-wool appearance.
Do not test these compounds for peroxides; let Chemical Waste Program personnel manage these containers. - Call the Chemical Waste Program if the container has a metal screw cap. Do not open the container. Metal capped containers
- Call the Chemical Waste Program if the container has been stored longer than two years.
Leave the container where it was found until Chemical Waste Program staff arrive:
If the container was picked up, gently put it down in a safe place. Do not shake the container or place it near sources of heat or ignition. Tape-off the area containing the potentially shock sensitive compound and warn laboratory personnel of its presence.
Testing Procedures
Routinely test the chemical on a monthly basis, after its expiration date, for peroxide formation.
If you determine the container is safe to open:
Test the peroxide-forming chemical with a commercial test strip. Commercial test strips have a test range of 0.5 to 50 ppm (mg/L) or 3 to 100 ppm. If peroxides are greater than the concentration range measured by the test strip, a serial dilution with deionized water is necessary to determine a semi-quantitative concentration of peroxides.
The following concentration guidelines apply:
| If: | Then: |
| Less than 80 ppm peroxides | Solution is okay for use |
| 80 ppm to 400 ppm | Call the Chemical Waste Program for packaging and removal |
| Greater than 400 ppm | Call the Chemical Waste Program, who will contact the Bomb Squad |
Commercial test strips:
Purchase from: Baxter Scientific Products, 1-800-642-3220, Curtin Matheson Scientific, 1-800-328-4523, Spectrum Chemical, 1-800-772-8786, Thomas Scientific, 1-800-345-2100, and VWR Scientific, 1-800-932-5000
Product name: EM Quant Ion Specific Test Strips, Peroxide Test: 0.5-50 mg/L
Catalog number and price: EM-10011-1, Pk.100/$30.00.
Product name: Baker Teststrips, Peroxide (H2O2): 3-100 mg/L. Catalog number and price: JT4416-1, Pk.100/$30.00. (Prices subject to change. Equivalent test strips from other vendors are also acceptable.)
Alternate Peroxide Test:
The procedure listed below only indicates the presence of peroxides and does not indicate their concentration.
To 10 ml of a 20 percent aqueous solution of the unknown add:
- Small spatula of sodium iodide or potassium iodide
- Five ml of distilled water
- Five ml of organic solvent (methanol or ethanol)
- A few drops of concentrated hydrochloric or sulfuric acid
An instant color change indicates the presence of peroxides
- yellow to faint orange = negligible amount of peroxides
- purple to dark violet or brown = peroxides present
If this procedure indicates a dark violet or brown color, call the Chemical Waste Program for packaging and removal.
Peroxide Inhibitor
If any peroxides are detected, a "dash" of butylated hydroxy toluene (BHT) should be added to the container to inhibit further peroxidation. Chemicals containing less than 80 ppm peroxides should have the BHT added, unless it is determined that the inhibitor will adversely affect experimental work.
Warning Label
A warning label should be affixed to all containers of peroxidizable compounds, as illustrated below, to indicate the date of receipt and the date the container was first opened.
PEROXIDIZABLE COMPOUND
Date Received __________
Date Opened ___________
Discard or test within 1 / 3 / 6 months after opening
(circle one)
Emergency Disposal
The Chemical Waste Program will have the Minneapolis Police Department Bomb Squad remove any containers of peroxide forming chemicals if:
- the chemical has a peroxide concentration of greater than 400 ppm,
- the container has crystals in or on it,
- the container is metal with a metal cap, or
- the chemical is suspected to be shock-sensitive due to its age.
Pick up of shock-sensitive material by the Bomb Squad typically occurs during the hours of 5:00 AM to 7:00 AM on the Twin Cities Campus and can be scheduled on coordinate campuses and experiment stations. You will need to be on-site during these hours to unlock doors and show Bomb Squad personnel where the container is located. A Chemical Safety Program staff person will be on-site to coordinate activities.
Table 5-2 Common Peroxide-Forming Chemicals
| Severe Peroxide Hazard on Storage with Exposure to Air Discard within 3 months |
|
| Diisopropyl ether (isopropyl ether) |
Potassium metal |
| Divinylacetylene (DVA) | Sodium amide (sodamide) |
| Potassium amide | Vinylidene chloride (1,1 dichloroethylene) |
|
Peroxide Hazard on Concentration Do Not Distill or Evaporate Without First Testing for the Presence of Peroxides Discard or test for peroxides after 6 months |
|
| Acetaldehyde diethyl acetal (acetal) | Ethylene glycol dimethyl ether (glyme) |
| Cumene (isopropylbenzene) | Ethylene glycol ether acetates |
| Cyclohexene | Ethylene glycol ether acetates |
| Cyclopentene | Furan |
| Decalin (decahydronaphthalene) | Methylacetylene |
| Diacetylene (butadiene) | Methylcyclopentane |
| Dicyclopentadiene | Methyl isobutyl ketone |
| Diethyl ether (ether) | Tetrahydrofuran (THF) |
| Diethylene glycol dimethyl ether (diglyme) | Tetralin (tetrahydronaphthalene) |
| Dioxane | Vinyl ethers |
| Hazard of Rapid Polymerization Initiated by Internally Formed Peroxides | |
| Normal
Liquids Discard or test for peroxides after 6 months |
|
| Chloroprene (2-chloro-1,3-butadiene) | Vinyl acetate |
| Styrene | Vinylpyridine |
| Normal
Gases Discard after 12 months |
|
| Butadiene | Vinylacetylene (MVA) |
| Tetrafluoroethylene (TFE) | Vinyl chloride |
Pesticides, Experimental
The University has several researchers who use experimental pesticides in their work. These experimental pesticides are only problematic as hazardous waste if the producer of the pesticide will not provide enough information about the formulation to allow proper categorization for disposal. In this situation, the Chemical Waste Program must test the pesticide and dispose of it as if it were an unknown. This is costly and also gives rise to some safety issues since the true hazards of the material are not fully known for handling and packaging purposes.
If you have any concerns regarding the stability of a chemical you wish to test, contact the Chemical Waste Program at (612) 626-6002 prior to testing.
Procedures
When planning to accept experimental pesticides for a research project, request that the producer agree to accept any residuals once the project is completed. The researcher should return the residuals in a timely manner.
If the producer will not accept the residuals, request the active ingredient and carrier information which would facilitate disposal. With this information, the waste may be prepared for disposal following normal procedures.
If the producer has not agreed to accept the residuals or provide adequate information about the pesticide, the material will need to be processed as an unknown. Call the Chemical Waste Program at (612) 626-1604.
Photo Fixer
Procedures
- Contact the Chemical Waste Program at (612) 626-1604 to obtain returnable 19 liter (5 gallon) containers. Note that other containers of various sizes may be used to submit the spent photo fixer, but they must be properly labeled and will not be returned to the generator for reuse.
- Place the hazardous waste accumulation label on the container. Record the contents, accumulation start date (the first day spent fixer is placed in the container), department name, and the name of a contact person.
- Do not fill containers to the top. Leave about 3 inches at the top of the container to facilitate the recovery process. Containers will not be collected if overfilled.
- Do not add other photo chemicals to the waste fixer container.
- Fill out a waste packing form for photo fixer and submit to CWP.
Picric Acid
Picric acid (2,4,-trinitrophenol) is common in laboratories. It is normally sold containing 10 to 15% water in a plastic-capped glass container and, in this state, is relatively safe to handle. Dry picric acid, however, can explode when exposed to friction, shock, or sudden heating. Moreover, picric acid can form salts on contact with metals, and heavy metal picrates are highly sensitive to detonation.
Procedures
If you have relatively fresh picric acid which is clearly still wetted, simply follow the instructions for regular hazardous waste.
If you have picric acid that appears to be dried out or in a metal-capped container, call the Chemical Waste Program at (612) 626-1604. A technician will come to your laboratory to assess the condition of the picric acid and perform the necessary steps to remove the container from your laboratory. This will entail attempting to wet the picric acid via immersion and/or making arrangements with the local bomb squad. If successfully wetted, the container will be processed as regular hazardous waste.
Pyrophoric Chemicals
Listed below are several classes of readily oxidized chemicals which can ignite spontaneously in air. Pyrophoric chemicals (within DDC hazard class designations 08 and 09), usually denoted by `PYR' in comments of the Registry (see Appendix I), should be stored in tightly closed containers under an inert atmosphere and any handling of them should be carried out under an inert atmosphere or liquid as well.
CAUTION: Do not attempt to open a container of dry picric acid!
Due to their highly reactive characteristics, contact the Chemical Waste Program (612) 626-1604 for special instructions concerning their handling and packaging.
Table 5-3 Pyrophoric Chemicals
Grignard reagents, RMgX
Metal alkyls and aryls, RLi, RNa, R3Al, R2Zn, e.g. trimethyl aluminum
Metal carbonyls, such as Ni(CO)4, Fe(CO)5, Co2 (CO)8
Alkali metals such as Na, K
Metal powders, such as Al, Co, Fe, Mg, Mn, Pd, Pt, Ti, Sn, Zn, Zr
Metal hydrides, such as NaH, LiAlH4
Nonmetal hydrides, such as B2H6 and other boranes, PH3, AsH3
Nonmetal alkyls, such as R3B, R3P, R3As
Phosphorus (white)
Shock-Sensitive Compounds
Some chemicals identified as shock sensitive have the potential to produce a violent explosion when subjected to shock, heat or friction, and require water to be added to the chemical before transportation.
Table 5-4 Shock-Sensitive Compounds
- Acetylenic compounds, especially polyacetylenes, haloacetylenes, and heavy metal salts of acetylenes (copper, silver, and mercury salts are particularly sensitive)
- Acyl nitrates
- Alkyl nitrates, particularly polyol nitrates such as nitrocellulose and nitroglycerine
- Alkyl and acyl nitrites
- Alkyl perchlorates
- Amminemetal oxosalts: metal compounds with coordinated ammonia, hydrazine, or similar nitrogenous donors and ionic perchlorate, nitrate, permanganate, or other oxidizing group
- Azides, including metal, nonmetal, and organic azides
- Chlorite salts of metals, such as AgClO2 and Hg(ClO2) 2
- Diazo compounds such as CH2N2
- Diazonium salts, when dry
- Fulminates such as mercury fulminate (Hg(CNO) 2)
- Hydrogen peroxide becomes increasingly treacherous as the concentration rises above 30%, forming explosive mixtures with organic materials and decomposing violently in the presence of traces of transition metals
- N-Halogen compounds such as difluoroamino compounds and halogen azides
- Oxo salts of nitrogenous bases: perchlorates, dichromates, nitrates, iodates, chlorites, chlorates, and permanganates of ammonia, amines, hydroxylamine, guanidine, etc.
- Perchlorate salts. Most metal, nonmetal, and amine perchlorates can be detonated and may undergo violent reaction in contact with combustible materials.
- Peroxides and hydroperoxides, organic
- Peroxides (solid) that crystallize from or are left from evaporation of peroxidizable solvents
- Peroxides, transition-metal salts
- Picrates, especially salts of transition and heavy metals, such as Ni, Pb, Hg, Cu, and Zn
- Polynitroalkyl compounds such as tetranitromethane and dinitroacetonitrile
- Polynitroaromatic compounds, especially polynitro hydrocarbons, phenols, and amines (i.e., dinitrotoluene, trinitrotoluene, and picric acid.
Note: Shock sensitive compounds have the letters "SS," "EX," or "TW" listed as the final two digits of their DDC number (see Appendix I).
For further information on explosive hazards of chemicals, see the National Research Council's guide, Prudent Practices in the Laboratory: Handling and Disposal of Chemicals, pages 54-57.
Unknown Chemicals
Before disposing of laboratory waste, its hazard class must be identified so that it can be transported and disposed of safely and in accordance with regulatory standards. For this reason, and for safety considerations of everyone working in the laboratory, do not allow containers of unknown chemicals to accumulate. Avoid generating materials of unknown composition by properly labeling bottles and boxes with the contents, its associated hazards, and the date the waste chemical was first added to the container. If required, inspect the condition of the containers and their labels weekly, documenting the inspections. If a label appears faded or illegible, affix a new label to the bottle.
In the event you are unsure of the exact contents of a chemical mixture or you have an unlabeled compound, you can assist the Chemical Waste Program in the analysis of the unknown item by examining the container and the contents and making some initial observations. Photocopy the Unknown Preliminary Analysis Checklist (see Appendix II) and complete the form, recording your observations and any known history of the material as requested.
Retain one copy of the completed form and submit a second copy to the Chemical Waste Program at the following address:
| CAMPUS MAIL Chemical Waste Program Dept. of Env. Health & Safety TCEM |
US MAIL Chemical Waste Program University of Minnesota TCEM-Thompson Center for Environmental Management 501- 23rd Avenue SE Minneapolis, MN 55455-0447 |
Or fax to: (612) 626-1571
Once the Chemical Waste Program receives the Unknown Analysis Checklist, it will be reviewed and a technician will be dispatched to your laboratory to analyze the unknown using a series of chemical tests. The technician will need to use a fumehood for these tests. If you have not been contacted by chemical waste personnel nor had your waste evaluated in two to three weeks, contact the Chemical Waste Program at (612) 626-1604.
CAUTION: Wear appropriate protective clothing and work in a hood when opening containers of unknown chemicals. Keep in mind the hazards involved in handling potential pyrophoric and peroxide forming chemicals. Several classes of chemicals can form explosive peroxides on long exposure to air. Unless it is known that the compound does not contain an explosive substance, do not use heroic efforts to open the bottle to examine the contents; it may be necessary to dispose of the bottle as a potentially explosive chemical. If you have questions concerning potential explosives, contact the Chemical Waste Program at (612) 626-1604.
Water-Reactive Chemicals
Certain chemicals react with water to evolve heat and flammable or toxic gases and should be stored and handled so that they do not come in contact with liquid water or water vapor.
Water reactive compounds, "xxWS" (DDC), such as those listed below, require special handling. Contact the Chemical Waste Program (612) 626-1604 for segregation and packaging instructions.
Table 5-5: Water-Reactive Chemicals
Alkali metals (sodium, potassium, etc.)
Alkali metal hydrides (lithium aluminum hydride, etc.)
Alkali metal amides
Metal alkyls, such as lithium alkyls and aluminum alkyls
Grignard reagents
Halides of nonmetals, such as BCl3, BF3, PCl3,
PCl5, SiCl4, S2Cl2
Inorganic acid halides, such as POCl3, SOCl2, SO2Cl2
Anhydrous metal halides, such as AlCl3, TiCl4,
ZrCl4, SnCl4
Phosphorus pentoxide
Calcium carbide
Organic acid halides and anhydrides of low molecular weight, e.g. acetyl chloride