Chemical Waste Disposal Routes
  1. To Drain with Dilution
  2. Blue Bag Route
  3. True Sharps Route
  4. Plastic Pipette Route
  5. Chemical Waste Store Route

There are five routes for disposal of chemical waste; each one is detailed below. The choice of route depends on the type of contaminated item and the hazards and quantities of the chemicals present. Identifying the hazardous properties is especially important. Chemical hazard data can be found on container labels, in suppliers’ Material Safety Data Sheets and in Chemical Hazard Assessments. Ask your Lab Manager for assistance if you are unable to find the necessary information. If there is any doubt about the correct disposal method, Lab Managers should consult SLS Health & Safety.

1. To Drain with Dilution

1.1. PLEASE NOTE: the following substances MUST NOT be disposed of to drains!

  • Mercury and its compounds.
  • Cadmium and its compounds.
  • Substances that may present an explosion risk or that have the potential to otherwise damage the drainage system.
  • Substances that react violently with water or release a hazardous gas when in contact with water.
  • Water insoluble/immiscible substances, e.g. organics.
  • Flammable substances.

Such substances must be collected separately and streamed to the Chemical Waste Store, unless section 1.2 is applicable.

1.2. If a safe method of inactivating or neutralising a hazardous substance exists, Safety Services recommends that, when reasonably practicable, this is carried out before disposal to drains. Some neutralisation/inactivation reactions have the potential to become quite violent and/or create additional hazards if they are not performed correctly. For this reason, only fully trained staff may perform them after prior consultation with Safety Services.

1.3. In general, chemical substances classified into the categories shown below may only be discarded to drain as very dilute solutions and in minimal quantities when it is not reasonably practicable to (1) separately collect the waste and stream it to the Chemical Waste Store or (2) filter out, or otherwise extract, the hazardous substance from the waste solution (e.g. activated charcoal extraction of ethiduim bromide from gel buffer).

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1.4. In general, small quantities (i.e. a few grams, a few 100mls or larger volumes of dilute solutions) of chemical substances not covered in sections 1.1 to 1.3 can be diluted with copious amounts of cold water and disposed of to drain. Larger quantities should be separately streamed to the Chemical Waste Store or, in the case of x-ray film fixer and developer, to the holding area in the WTB basement.

2. Blue Bag Route (updated 18/04/19)

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2.1. Yellow bins lined with heavy-duty blue bags are used for the disposal of:

  • Solid items contaminated with MINIMAL quantities of liquid only.
  • Items that are, or may be, TRACE contaminated with hazardous chemicals (excluding those indicated in sections 2.2 and 2.3). For example: plates, dishes, tubes and pipette tips that have been emptied and have only residual liquid adhering to their inner surfaces; gloves and tissues that are not heavily contaminated with a hazardous chemical; empty chemical containers (with label removed/defaced); empty weigh boats; polyacrylamide gels.
  • Items contaminated with, or quantities of, non-hazardous chemical substances.

Safety Services are responsible for removing full blue bags and replacing them with fresh bags.

2.2. Blue bags are sent for disposal to landfill, therefore, it is important that only TRACE quantities of hazardous chemicals enter this waste stream. Chemicals falling into the categories shown below are of special concern and may only be discarded to blue bags in MINIMAL quantities* when it is not reasonably practicable to separately collect the waste and stream it to the Chemical Waste Store.

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*When discarding material contaminated with chemicals falling into any of the categories listed above, the user MUST keep the amount of hazardous chemical present in the blue bag down to less than 0.1% of the total weight of waste in the bag. If contamination is only trace and the contaminating substance a dilute solution, this should be achievable. However, if the 0.1% threshold could be exceeded, the waste MUST be collected separately and streamed to the Chemical Waste Store.

2.3. Items that must not be disposed of via the Blue Bag waste route

2.3.1. Chemicals categorised as explosive, oxidising and flammable MUST NOT be deposited in the blue bags. Such waste must be collected separately and stored in a fume hood until its removal to the Chemical Waste Store.

explosionoxididationflame

2.3.2. Chemicals that may give rise to hazardous fumes or a pungent odor MUST NOT be deposited in the blue bags. Such waste must be collected separately and stored in a fume hood until its removal to the Chemical Waste Store.

2.3.3. Biological material (i.e. micro-organisms, cell cultures, blood/tissue), true sharps and large plastic pipettes MUST NOT be disposed of via the blue bag route. Also, items that a lay person could consider to constitute biological waste MUST NOT be disposed of via the blue bag route. This includes serum bags and other items that appear clinical in nature.

2.3.4. Glass, any amount, intact or broken, MUST NOT be disposed of in the blue bag waste.

2.4. Blue bags MUST NOT be overfilled. Once three quarters full, inform your Lab Manager. Do not attempt to tie off the blue bag or remove the full bag from the bin. Do not seal the lid onto the bin. Also, consider the weight of the contents of the bin and avoid overloading it to the point where it may become a manual handling hazard.

3. True Sharps Route (updated 13/06/16)

sharpsafe

3.1. The following items must be disposed of via this route:

  • Needles (on their own or attached to syringes); scalpels; other types of cutting blade; glass pasteurs; microscope slides and coverslips; other intact, small glass items that will easily fit into the sharp-safe; broken glass that will easily fit into the sharp-safe.

3.2. Items that must not be disposed of via this route:

  • Larger intact glass items and pieces of broken glass that will not easily fit into the sharp-safe. Such items must be thoroughy and carefully decontaminated and disposed of via the uncontaminated glass route .
  • Uncontaminated or trace contaminated plastic pipette tips. Note: biologically contaminated plastic pipette tips must be disposed of as per the CL1/CL2 waste disposal route.

3.3. The contaminated item must be fully emptied/discharged to ensure only trace amounts of chemical contamination remain and deposited in an approved yellow sharpsafe (available from WTB Stores). Do not overfill sharpsafes! Once full to the maximum fill line, typically where the body of the container meets the lid, engage the permanent closure. Use a permanent black marker pen (please do not use tape; write directly onto the container) to clearly label the sharpsafe with your name, group and the word "Waste" and place in the designated chemical waste storage area.

3.4. If sharps are contaminated with a chemical that gives rise to hazardous fumes or a pungent odor the sharpsafe must be used only for chemically contaminated sharps and kept in a fume hood prior to uplift by Safety Services.3.5. The restrictions/considerations applying to the Blue Bag Route , as outlined in section 2.2 , also apply to the True Sharps Route.

4. Plastic Pipette Route (updated 4/12/06)

4.1. Large plastic pipettes must be fully discharged of any liquid to ensure only trace amounts of chemical contamination remain. Bins must not be overfilled!

  • In areas where pipettes are used only in conjunction with chemicals, i.e. no biological material is used, deposit in a Blue Bag bin. Please note: if contamination is significant the blue bag route must not be used. Bag and seal the pipettes in a clear bin liner then pack into a cardboard box (the one in which the pipettes arrived would be ideal), ensuring there is no possibility of leakage, and get it uplifted by Safety Services along with the other chemical waste containers.
  • In areas where pipettes are used in conjunction with chemicals and biological material, place in a lined, white, plastic biohazard bin. Once full, liners are loosely sealed and taken by the CTS Technician for autoclaving. The CTS Technician will place a fresh liner in the plastic bin. After autoclaving, pipettes are placed in heavy duty bin liners and discarded with the black bag waste. Please note: as for any waste being streamed to the autoclaves, it is vital that only trace amounts of chemical contamination are present. If chemical contamination is significant the pipettes must not be sent for autoclaving .

4.2. If pipettes are contaminated with a chemical that gives rise to hazardous fumes or a pungent odor they must be collected separately and kept in a fumehood prior to uplift by Safety Services.

4.3. The restrictions/considerations applying to the Blue Bag Route , as outlined in section 2.2 , also apply to the Plastic Pipette Route .

5. Chemical Waste Store Route
(Last updated 11/02/09)

5.1. When the routes detailed above are inappropriate, chemical waste must be collected in correctly labelled (see section 5.3 for labeling instructions), suitable containers - i.e. robust, leak proof, easily handled, chemically compatible - then streamed to the Chemical Waste Store at the west end of the MSI building. Safety Services staff are responsible for transferring chemical waste from the SLS labs to the Chemical Waste Store, and arranging for its eventual uplift by a specialist contractor. Waste collections should be arranged with Safety Services Hazardous Waste Manager.

5.2. Mixtures of chemicals may be unavoidable but, if possible, keep different chemicals separate and ensure that incompatible chemicals are never mixed, for example: non-chlorinated and chlorinated solvents; oxidising agents and combustibles/flammable solvents. Incompatibles will be specified in a chemical’s hazard assessment/safety data sheet.

5.3. Waste containers must be clearly labelled with:

  • the proper chemical name;
  • the nature of the waste, e.g. solid, liquid, contaminated plastics;
  • the amount;
  • nature fo the hazard (e.g. flammable (see section 5.4), toxic, corrosive etc) and any other properties that Safety Services should be aware of;
  • laboratory of origin;
  • name and contact number of the person packaging the waste.

If a container holds a mixture of chemicals the relevant details must be given for each one. Note: unknowns will not be accepted by the specialist contractor!

5.4. In the Chemical Waste Store, flammables are stored in a purpose-built flammable waste holding area, separate from other chemical waste, to reduce the risk of fire. It is, therefore, vital that flammable waste is clearly labelled as such.

5.5. Chemicals classified as Controlled Substances must not be deposited in the Chemical Waste Store. Contact Safety Services for further advice on this issue.

5.6. In cases where chemical waste has unusual and/or extreme hazardous properties, it may be necessary to inform Safety Services in advance of its collection to allow them to take the necessary precautions.