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Lab Safety Training Guide


 

SECTION 9: Chemical Waste Disposal

EHS coordinates disposal of chemical waste from University operations. The cost of waste disposal is borne by EHS, rather than the individual drum laboratories, in part to eliminate the incentive not to use this procedure for disposing of chemical waste.


This procedure applies to any chemical substances generated from University operations (including laboratories, administrative units, and physical plant operations) that are classified as hazardous based on the criteria described below. This procedure does not apply to the disposal of biohazardous or radioactive wastes. Contact EHS for more information about disposal of these materials.


The Waste Disposal section of the EHS web page contains more detailed information.


Classification of Waste as Hazardous (top)

Waste is considered hazardous if:

  • It is on either of two lists of specific chemical substances developed by the Federal Environmental Protection Agency (EPA). Most commonly used organic solvents (e.g. acetone, methanol, toluene, xylene, methylene chloride etc.) are included. For a detailed listing contact Environmental Health & Safety.
  • It is on a list of nonspecific sources that includes a broad range of spent halogenated and non-halogenated solvents.
  • It is on a list of specific sources that includes primarily industrial processes.
  • It exhibits any of the following characteristics as defined by the EPA (abbreviated definitions):


    Ignitable: a liquid with a flash point less than 60 degrees Centigrade; not a liquid and capable under normal conditions of causing fire through friction, absorption of moisture or spontaneous chemical changes; an ignitable compressed gas; or an oxidizer.


    Corrosive: aqueous and has a pH less than or equal to 2 or greater than or equal to 12.5 OR a liquid that corrodes steel at a rate greater than 0.250 inches per year at 55 degrees Centigrade.


    Reactive: normally unstable; reacts violently with water; forms potentially explosive mixtures with water; generates toxic gases, vapors or fumes when mixed with water; cyanide or sulfide wastes that generate toxic gases, vapors or fumes at pH conditions between 2 and 12.5; capable of detonation or explosive decomposition if subjected to strong initiation or under standard temperature and pressure; OR classified as a Department of Transportation explosive.


    Toxicity Characteristic:
    an extract of the waste is found to contain certain metals, pesticides or selected organics above specified levels OR otherwise capable of causing environmental or health damage if improperly disposed (this is a judgment you must make based upon your knowledge of the material from the MSDS.


Packaging Chemical Wastes (top)


Materials that are to be disposed of as hazardous waste should be placed in sealable containers. Waste disposal cost is based on volume, not weight, therefore, whenever possible, containers should be filled, leaving a headspace for expansion of the contents. Often the original container is perfectly acceptable. If you routinely generate significant quantities of compatible solvents, bulking of waste in five-gallon carboys provided by EHS may be practical.

funnelThe container should not react with the waste being stored (e.g. no hydrofluoric acid in glass). Similar wastes may be mixed if they are compatible (e.g. flammable liquids).

Wastes from incompatible hazard classes should not be mixed (e.g., flammables with oxidizers). Certain metals also cause disposal problems when mixed with flammable liquids or other organic liquids (see Special Problems). Containers must be kept closed except during actual transfers. Do not leave a hazardous waste container with a funnel in it.

Chemical containers that have been emptied should be triple-rinsed and air-dried in a ventilated area. Once this has been accomplished, the container can be disposed of as regular recyclable trash. If the original contents were highly toxic the container should be rinsed first with an appropriate solvent and the washings disposed of as hazardous waste. More specific information about disposal of empty chemical containers can be found on the EHS web page.


Labeling of Waste Containers (top)

Waste containers must be labeled with the words HAZARDOUS WASTE along with the names of the principal chemical constituents and the approximate label percentage. Waste container labels can be obtained by contacting Environmental Health and Safety at x8-5294. Use of these labels is preferred, but not mandatory, unless the waste will be placed in storage before disposal. If you choose not to use the standard labels, the container still must bear the words HAZARDOUS WASTE and the chemical contents. Label the collection container as soon as accumulation begins.

Do not list reactants, only products. For example, if a cyanide was used in a reaction but all of the material was oxidized to a cyanate before disposal, do not list cyanide on the label. Use chemical names not symbols, structural diagrams or product trade names.

Labeling should be accurate and legible and should include the name of the generator, the name of the Lab Group or PI, and an extension where someone who is knowledgeable about that specific waste can be reached on the day of the pickup in case questions arise during packaging for disposal.


Disposal Procedure (top)

Chemical Waste Pickups are generally scheduled for the last Thursday of the month through the academic year. A notice of the pickup is distributed to Departmental Chemical Hygiene Officers, Department Safety Managers and other interested persons approximately one week in advance via the Waste Paper. Contact EHS at 8-5294 if you would like to receive this newsletter.


Pickups take place at four Main Campus locations:


Lewis Thomas Laboratory loading dock – for Molecular Biology, EEB and Geosciences


E-Quad (loading dock) – for SEAS and PMI


Frick loading dock – for Chemistry, Psychology and Visual Arts


Jadwin Room 124 – for Physics only


Specific arrangements for getting material to the pickup site are the responsibility of the individual departments. Refer questions of this nature to your Departmental Safety Manager or Chemical Hygiene Officer. Generally, wastes must be at the pickup site by 9 AM the day of the pickup to be included.


Special Wastes (top)

Thallium, Beryllium, and Osmium pose special disposal problems - especially when in combination with other wastes. If you will be generating wastes containing these elements please contact EHS before you begin.

thermometer
Metallic mercury is considered a recyclable, rather than hazardous waste. If you generate mercury waste or have mercury debris from a spill or equipment breakage, contact EHS to arrange a special pickup.


Ethidium Bromide usually does not need to be disposed as hazardous waste. Electrophoresis gels containing trace amounts of ethidium bromide (less than 0.1%) may be placed in regular laboratory trash. Gels containing more than 0.1% (usually dark pink or red color) should be placed in the medical waste boxes. Ethidium bromide solutions may be neutralized and disposed down the drain. Neutralization procedures are outlined on the EHS web page (www.princeton.edu/~ehs/etbr.html).


Used Oil: Used oil is not disposed of as part of the Hazardous Waste program, with the following exceptions:

  • Vacuum Pump Oil
  • Cutting Oils
  • PCB Contaminated Oil
  • Oil mixed with hazardous wastes

EHS does not coordinate or pay for used oil disposal. For more information, see the EHS web page.

Silica gel, molecular sieves and dessicants are not considered hazardous waste unless they are grossly contaminated.


Uranium and thorium compounds, such as uranyl acetate, uranyl nitrate, uranyl formate, uranium oxide, thorium nitrate and thorium oxide, are considered radioactive waste, rather than chemical waste. See the Waste Disposal web page for more information.


Chemical wastes that are combined with radioisotopes are considered mixed waste. Contact the Radiation Safety Officer at 8-5294 before generating this type of waste. Mixed waste is difficult to dispose and should be minimized to the extent possible.


Do not bring wastes to the pickup site that are not properly identified. The disposal company can not legally transport or dispose of them. Arrangements for chemical analysis of unknowns can be made through EHS. Costs associated with improper management of hazardous waste (e.g. characterization of unknowns, special handling of peroxidizable compounds etc.) are charged back to the generator department.


Sharp Implement Disposal (top)


Many individuals on campus have occasional or routine need to dispose of sharp implements or “sharps”, such as razor blades or other cutting blades, broken glass, glass slides, syringes, or other items that can easily puncture the skin. It is important that these types of sharp implements not be placed directly into trash receptacles with other general trash or in the paper-recycling receptacle in order to prevent injury to those who must handle the general trash and recyclables coming from the offices, labs and shops.

Sharp implements must be placed in a puncture-resistant container, such as rigid plastic or corrugated cardboard. For example, an occasional razor blade that needs disposal could be placed in a disposable plastic container with a screw-top lid or could be wrapped in a piece of corrugated cardboard and secured with packaging tape. For sharps that are routinely generated, a sealable box or container should be used.


General Recommendations (top)

  • Don’t purchase more of a chemical than you expect to use in the foreseeable future. The costs of disposal often exceed the purchase cost by a considerable margin.
  • Scale down experiments to a practical minimum to reduce the total amount of waste generated.
  • Consistent with safe practice, bulk compatible waste in containers up to five gallons in capacity to reduce disposal costs (consult with EHS first).
  • Keep all chemical containers clearly and unambiguously labeled.
  • Keep all containers of waste sealed except during filling. Do not leave funnels in containers.
  • Dispose of your wastes at the completion of a project - don’t abandon them for someone else to deal with later.


Waste Minimization and Pollution Prevention (top)


Waste minimization is a national policy and the responsibility of each person who generate hazardous waste. Princeton University is committed to managing operations in an environmentally sensitive and responsible manner. Everyone must do his or her part in minimizing hazardous waste generation.

General principles for waste minimization, in order of priority, are:

  1. Elimination - any modification that results in the elimination of waste generation.
  2. Substitution - replacement of hazardous substances with less hazardous materials.
  3. Scale Reduction - a reduction of the amount of hazardous materials used in a procedure.
  4. Recycling - the reuse of waste materials either back into the same process or into a different process.
  5. Reclamation - any process that allows materials to be used again after some sort of purification, such as solvent distillation.
  6. Treatment - an additional step added to an experimental or analytical procedure to reduce or eliminate the toxicity of the waste.


Contact EHS for consultation on ways to reduce waste in your operations. Report any successful waste minimization projects to EHS in order to share these practices with other labs. See the Waste Disposal section of the EHS web page for more information.


Section 8 Appendix A

       
       
     

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