Strict legislation controls the disposal of chemical waste and clearly defines the Duty of Care of all waste producers regarding the identification, segregation, packaging and transport of waste. The following guidance notes have been compiled to assist you in correctly preparing your chemical waste for disposal via the Departmental Chemical Waste Store. These notes should be read in conjunction with the information contained in the Safety Handbook (Section 12.11 – Disposal of Chemicals).
The following CANNOT be disposed of via the Chemical Waste Store under any circumstances:
If you want to dispose of any of the above and do not have a defined disposal route, contact the DSO for further information.
1. Use the right container for the type of waste you have!
a. Glass bottles can be used for most chemicals EXCEPT hydrofluoric acid waste.
b. Plastic bottles are suitable for acids and alkalis. DO NOT put aggressive solvents such as ether or dichloromethane, or mixtures containing aggressive solvents, in plastic containers as they soften and begin to dissolve unless the container is made of HDPE (high density polyethylene)!
c. Steel drums are suitable for organic solvents, neutral aqueous solutions and oils but are NOT suitable for acids or alkalis. Acidified solvent mixtures should be placed in glass bottles.
d. Self-venting bottles e.g. hydrogen peroxide bottles MUST be put inside another container (secondary containment).
e. Containers designed for solids e.g. empty sand bottles/silica bottles MUST NOT be used for liquids.
f. Solid waste can be disposed of in plastic containers or double-bagged (using good grade sealed plastic bags, one inside the other).
g. DO NOT mix solids and liquids in the same container (gloves, plastic tips etc. floating in solvent is not acceptable).
2. Ensure that the bottle or container being disposed of is sound i.e. there are no cracks, chips or punctures; it is not leaking or corroded; it is securely fastened and is free from external contamination. Where external contamination is suspected, containers must be sealed inside a clear plastic bag or placed into a secondary container.
3. Correctly label your waste, in English. Use full chemical names. No abbreviations or chemical formulae – remember, not everyone who handles the waste is a chemist! Give as much detail as possible about the contents and remember to list the major components, including solvents, e.g. is the waste in water i.e., aqueous waste, or in ether etc.; what is the pH? Give as much information as you can!
4. Where possible, use the original container. If you are disposing of a chemical in its original container, don’t cover the suppliers label (e.g. the Aldrich bottle label) as this contains valuable identification and safety information. HOWEVER, it is important to deface or remove any labels on containers which are incorrect.
5. Laboratory glassware e.g. round bottomed flasks, Schlenk tubes etc. with material in them will NOT BE ACCEPTED for disposal. If you can’t transfer the contents to a waste bottle (e.g. the flask stopper is seized) then place the flask inside a suitable secondary container packed with vermiculite.
6. Be particularly careful not to over-fill glass waste containers. Leave ‘head space’ to allow for liquid volume expansion in any container. Ideally, Winchesters should be filled to the bottom of the neck and no higher. If the Winchester contains a highly or extremely flammable liquid they should not be filled above 3/4 full. In the warmer weather, caps should not be over tightened and Winchesters should not be filled more than 2/3 full.
7. Leave at least a 30mm air-space above the liquid level in steel drums to allow for volume expansion. Bungs on the steel drums must be correctly tightened.
8. Inert solids – where they are not grossly contaminated, these can be disposed of in the silica waste bin or, if inert and soluble, can be washed down the drain with lots of water. Consult the DSO first if you are unsure.
9. Paper and gloves:
a. Dispose of as general waste unless grossly contaminated.
b. If grossly contaminated, then either double-bag (using good grade sealed plastic bags, one inside the other) or put in a suitable plastic container (e.g. sand or silica containers).
10. Metal gas canisters/lecture bottles/metal pressurized cans may be disposed of via the Chemical Waste Store but they MUST be clearly labelled stating whether they are empty or not. Metal canisters/lecture bottles/metal pressurized cans are expensive to dispose of if they are not empty. Rather than buying a lecture bottle consider renting from a supplier to whom it can be returned after use e.g. BOC’s ECOCYL® refillable gas cylinder may be a suitable alternative to traditional non-refillable, non-returnable cylinders.
11. Chemically contaminated sharps (e.g. needles used for transferring chemicals, scalpel blades etc.):
a. A limited supply of white plastic buckets with lids that can be emptied and reused are available from the Chempack Chemist BUT these do not have the needle removing arrangement in the lid. Yellow sharps bins are available from Stores; these have devices in their lids to facilitate the removal of needles (sheathed or unsheathed) from syringes so they fall directly into the sharps bin.
b. YOU MUST clearly label the sharps bin with your name, lab number and contact phone number. REMOVE ANY BIOHAZARD LABEL / TREFOIL as well as any reference to the UN Carriage Number (UN 2814 Infectious Substance).
c. Residual low-level chemical contamination of sharps is acceptable.
d. Do not use ‘chemical sharps’ bins for any other type of waste, e.g. paper, gloves, ethidium bromide gels, biological or radiological waste. Use proper disposal routes for these. Sharps used for handling biological material MUST go in a separate sharps bin.
e. Do not overfill sharps bins. Once at the full indicator line, close the lid and take to the Waste Store.
1. Keep different types of waste separate as far as possible, e.g. cyanides away from acids, oxidisers away from organics. Think chemical compatibility!
2. Pay special attention to waste containing iodine. VERY CLEARLY label it! (The Government’s Environment Agency place very strict controls on the amount of iodine incinerated per day by the University Hazardous Waste Contractor.)
3. Cyanide reaction waste can be sent for disposal via the Chemical Waste Store WITHOUT prior neutralisation. Sufficient ‘head space’ should be left in the container to avoid over pressurisation in the event of an adverse reaction.
4. Untreated Aqua Regia and nitrating mixtures will NOT BE ACCEPTED for disposal. These MUST be carefully diluted into at least an equal volume of water so that they are no-longer able to nitrate or evolve gas prior to placing in the Chemical Waste Store.
5. Piranha solution waste: see http://www.ch.cam.ac.uk/safety/general-guidance.
6. Reaction mixtures containing acid chlorides must be neutralised prior to disposal.
7. For small amounts of organometalics e.g. residues in dead empty bottles of alkyl lithiums and Grignard Reagents etc., it should be possible to safely destroy these residues using an approved procedure (hydrolysis and/or neutralisation with adequate cooling) within a fume cupboard in the lab. Only attempt to destroy small amounts at any one time.
8. ALL elemental mercury waste (e.g. thermometers, manometers, reference electrodes etc.) MUST be placed in a robust container for disposal. NOTE: the use of elemental mercury, mercuric compounds and equipment containing mercury is restricted in the Department due to the Trade Effluent Consent imposed by the Government’s Environment Agency.
9. Precious metals e.g. chelated gold/silver/palladium etc. No facility exists for their recovery or for them to be recycled. However, if significant quantities are generated, contact the DSO.
1. Before your waste can be deposited in the Chemical Waste Store you must fill out the disposal form (Word, Word with forms, PDF).
2. Each item to be disposed of must be clearly labelled and numbered – the number on the label should correspond to the number on the form. It is also good practice to write the date of disposal on the label, which should also correspond to the date on the form. Please do not use a felt tip pen to label your waste. A permanent marker or preferably a biro should be used. Please ensure that all waste labels are legible.
3. Remember, when filling out the form, always use the NAME of the chemical in English; do not write formulae!
4. If a liquid, state if solution is aqueous; if non-aqueous, state which solvent. Give the pH if known. Estimate the amount of any substance dissolved in the aqueous solution / solvent.
5. Record the volume of the container e.g. Winchester, 1kg (if using a silica or sand pot) etc.
6. State the type of container used from the options given.
7. Record if Harmful/Irritant etc. again using the options listed. If you are unsure, the default is ‘Harmful’.
8. Once you have listed your waste on the form, make a photocopy. You will be required to leave a copy of your completed disposal form with Reception BEFORE the key to the Waste Store will be issued to you.
9. Place the chemicals in a sturdy box (preferably plastic) for transport and temporary storage in the Chemical Waste Store along with a copy of the form (in a plastic wallet).
10. For single bottles, the form should be secured to the outside of the container.
1. The key to the Waste Store can be obtained from Reception between 09:00hrs and 16:00hrs, Monday to Friday.
2. DO NOT take your waste to Reception ‘en-route’ to the Waste Store.
3. Boxes of chemicals and bottles should be placed on the shelving on the left-hand side of the Store ONLY (as you walk in).
4. DO NOT interfere with, or place anything on the right hand side of the Store.
5. Lock the Store and return the key to Reception IMMEDIATELY. You will need to sign to say you have returned it.