Hazardous Waste

It's important hazardous waste is collected and disposed of correctly to avoid harming others, the environment or facilities. Please be aware that:

  • You must ensure hazardous wastes are not mixed with other hazardous waste and that non-hazardous and hazardous waste are not mixed (unless it is part of the experimental procedure)

  • You must segregate and dispose of waste correctly

  • WEEE (Waste Electrical and Electronic Equipment) items may be hazardous waste

  • You must follow safety precautions as described in COSHH when handling hazardous waste

Hazardous Waste Procedure

Follow the below step to arrange collection of hazardous waste:

  1. Follow the waste disposal procedure described in the COSHH form or follow specific lab disposal procedure (e.g. some labs use a waste logbook to keep track of contents in waste containers)

  2. Waste MUST be safely packaged in appropriate containers

  3. Waste container MUST be labelled with with contents and concentrations (include pH when relevant)

  4. Arrange disposal by completing the Waste Form and email it to chemicals@materials.ox.ac.uk 

  5. Store wastes safely until it has been collected - do not accumilate hazardous waste / dispose of hazardous waste regularly

NOTE: Hazardous waste is only accepted when the above steps have been followed. 

Supervisors are responsible for monitoring hazardous waste in their areas to ensure waste procedures are followed, waste is not accumilated and to prevent unknown wastes.

How To

It's an important part of the COSHH assessment to determine if waste is hazardous or not which is completed before experimental work can begin. Do not generate hazardous waste without knowing how to package and dispose of it correctly.

Information to include in the waste disposal section of a COSHH:
  1. Describe all the waste that will be produced as part of the experiment/procedure.
  2. Determine if the waste is hazardous or not
  3. Include the waste route (e.g. general waste, hazardous waste, glass bin, sharps bin)
  4. For hazardous waste: include a suitable description to be used on the labelling (see tab 3), specify container materials where relevant (see tab 2) and the primary hazard for transportation (see tab 4) - a draft waste form may be attached to the COSHH.
    In some labs there are shared hazardous waste containers, in such instances a) make sure you receive an induction in the waste procedures so that incompatibles are not accidentally mixed. b) Contents must be noted down in a logbook so that the final concentrations can be calculated. c) indicate in the COSHH which hazardous waste container will be used (e.g. halogenated, non-halogenated, inorganic acids)
Common examples of waste that are normally not considered hazardous but may change if it has been used for handling of particularly hazardous or potent substances:

Nitrile gloves, trace or no visual contamination, are disposed of in the general waste bin

Glass vials, rinsed and trace or no visual contamination, are reused or disposed of via the clean, broken glass bin.

Pipette tips, discharged, are not considered hazardous and are disposed of via general waste.

Tissue paper, used to clean work area, trace or no visual contamination, are disposed of via the general waste bin.

Examples for common waste disposed of as hazardous waste:

Leftover Hydrofluoric acid etchant is collected in PTFE containers. Containers are filled to a maximum of 3/4 to allow for expansion. The container will be labelled similar to: 'Hydrofluoric acid 5% in water, pH1'. Primary hazard for transportation is corrosive. Secondary hazard is toxic. Dispose of waste regularly via hazardous waste by completing the waste form and email it to chemicals@materials.ox.ac.uk 

Cleaning solvents are collected in 2.5L containers. Contents are noted in the waste logbook. The container will be labelled similar to (depending on concentrations): 'Ethanol (50%), methanol (25%), Isopropanol (25%) - used to rinse clean samples'. Primary hazard for transportation is flammable. Secondary hazard is toxic. Dispose of waste regularly via hazardous waste by completing the waste form and email it to chemicals@materials.ox.ac.uk   

Sulfides (LiPSCl, lithium sulfide and similar), trace, no visible contamination on nitrile gloves. This waste should not be disposed of via general waste is it is very smelly. Instead collect in 6L white drum with red lid. The drum will be labelled similar to 'lithium sulfide (trace, not visible) on gloves'. Dispose of via hazardous waste as nuisance waste by adding 'smelly' in the hazard identification section. Primary hazard for transportation is NH. Dispose of waste regularly by completing a waste form and email it to chemicals@materials.ox.ac.uk   

The container must be UN approved and compatible with the contents

  • No bigger than 10L (as container may otherwise be too heavy for manual handling)
  • Containers that have previously been used for transporting chemicals such as solvents, can be used for wastes as long as it has been cleaned and compatible.
  • Chemicals can also be sent for disposal in their original container without being decanted into a new container - unless the original container is damaged or brittle/unsafe 

Examples of compatible containers for different types of hazardous waste: 

Chemical

UN container material
Hydrofluoric acid (HF)

Teflon or high Density Polyethylene (HDPE)

DO NOT USE GLASS!
Perchloric acid Glass
Organic solvents HDPE or glass
Aqueous acids and alkalis HDPE

 

NOTE Containers for liquid wastes must be equipped with screw caps.

Containers for solid wastes must have removable lids.

 

 

FBC Logistics un_markings - FBC Logistics

Example UN stamp that can be found on containers

please follow this link if you would like to know more about UN packaging and packaging groups

https://www.royalchemical.com/blog/what-are-un-packaging-codes

 
Clarification of commonly misunderstood uses of container for hazardous waste disposal:

 

Check the waste container is not overfilled

  • There is often a mark on the container showing the ‘max fill point’ if not, then only fill up to the shoulders of the container or ¾ full.

The container must not be brittle, have bulging/misshaped sides, cracks or other damage

  • Oxidizing wastes such as hydrogen peroxide, nitric acid >5% and others must be equipped with a vented cap (available from Stores)
  • Plastic containers are usually guaranteed for 5 years of the production date. After this date the container may no longer be suitable

The container must be clean on the outside

  1. Clean/wipe the outside with damp tissue paper
  2. If not possible, for heavily contaminated containers; use overpacking or a secondary container

The container must not leak

  • Check especially at the lid/cap. If there is a leak:
    1. Tighten the lid further
    2. Replace the lid or container
    3. Use overpacking or a secondary container which is compatible with the contents and appropriate for the type of waste i.e some UN containers are only approved for solids or liquids within a certain packaging group

There must be a waste label attached and the description must match the description that is used in the waste form

  • Waste labels can be acquired from Stores for free - See more information in Tab 3 on how to label waste correctly
Click here to download a printfriendly version of a Container Checklist that can be displayed or used in the lab

 

Basic Labelling Examples
  1. Do not add a waste label to hazardous waste that is being disposed of in its original container i.e. no need to add additional labelling to an already labelled container unless the contents have changed or it is contaminated
 unwanted chemicals - does not include samples
  1. Make the description relevant and reflects the contents. Start with the reason why the waste require disposal via hazardous waste

‘Colloidal Silica (25%w/w) in water’

‘Single walled carbon nanotubes visually contaminated on gloves and tissue – no loose powder’
  1. Only list concentrations in w/w% (weight/weight percentage) or g/L i.e. do not use Molar. (convertion formula available under 'Useful Information' at the bottom) 

Note, in some instances it can be difficult to determine the concentration in %w/w, instead describe the contamination i.e. is the trace contamination visible or not visible? 

'Potassium Permanganate (5g/L) in water’

‘Diethyl Carbonate (33%), Ethylene carbonate (33%), Propylene carbonate (33%), Sodium hexafluorophosphate (17g/L) and Lithium hexafluorophosphate (15g/L)’

 

‘Lithium sulfide (trace, not visual) contamination on gloves and tissue – smelly’

 

'Tungsten (nano powder, trace) visual contamination on gloves and tissues’

  1. Include pH if the liquid waste contains a corrosive substance (H314)

Note, not necessary for unwanted chemicals in the original containers.

'Sodium hydroxide (8g/L) in water, pH 12’

‘Ethanol (75%), Methanol (10%), Hydrochloric acid (10%), water (5%) – pH1’
  1. Substances below 0.1%w/w in liquid waste may be listed as trace

'Toluene (75%), Hexane (15%), Ethyl acetate (10%) with trace of fullerenes and carbon’
 

‘Hydrochloric acid (5%) trace lithium nickel manganese cobalt oxide, pH1’

 

Labelling for Specific Substances: Examples:
  1. State in the description if there is a considerable amount of visible solids in the waste or if it is a suspension.

'Isopropanol (39%), Lithium Iron Phosphate (10g/L), Carbon black (1g/L) in water, solid/liquid’

‘Diamond suspension (10%) in water’

  1. FOR SPILLS; state in the description if it contains:

  • loose liquid. Applies to liquid spills, oily rags etc.

  • Sharps e.g. broken glass, syringe needles.

    Note, it is not appropriate to double bag liquid spills where there is a significant mount of loose liquid - use more spill pads or collect in a container. Neither is it appropriate to use bags as the primary container for sharps - use an appropriate container/drum.

'Isopropanol spill (approx. 100mL), 2x pink spill kit pads, 1x pair of nitrile gloves – no loose liquid’

‘Isopropanol spill (approx. 2000mL), 7x pink spill kit pads, 2x pair of nitrile gloves and 1x broken 2.5L Winchester bottle – contains broken glass and approx. 50mL of loose liquid’

 **would require an overpack (double bagging is not appropriate due to glass shards and liquid)**
  1. Add the particle size for solid/powder waste (if known) as it may change the hazards of the substance
 e.g. reactivity may increase as surface areas increase such as for metals 
  1. For alkali metals such as Lithium, Sodium and Potassium, state in the description that the metal is submerged in mineral oil i.e. metal is completely covered by the oil. For Lithium metal, use light mineral oil.

'Lithium metal (discs, pieces and ribbon) submerged in mineral oil’

‘Potassium metal chunk (approx. 5x2x2 cm) (10g) submerged in mineral oil’

 

  1. Ensure the newest format of the waste form is used
  2. Description of waste must match the labelling on the container
  3. Total amount of waste: add up (in g/kg or mL/L) the total of waste in all containers
  4. No. of containers: list how many containers there are and the size(s)
  5. List hazard numbers in the same order as the substances appear in the description. Add a comma or slash between substances. Include any EUH numbers which may appear at the end of section 3 of the SDS. It is not necessary to add hazard numbers for trace contaminants and if a substance does not have hazard numbers i.e. it is not considered hazardous; add NH (not hazardous).
    Preferably use SDS by Sigma-Aldrich/Merck or other European suppliers as hazard statements may vary slightly from region to region
  6. Primary and secondary hazard - see below example for guidance
  7. Inorganic (I) or Organic (O): list as O if there is more than 1% of organics in the waste

Examples:

 

Determining the primary hazard for transportation

1. Hazardous waste consisting of a single hazardous substance:

The Primary hazard for transportation is easily found by looking up section 14 of the relevant SDS (Safety Data Sheet).

E.g. below is section 14 from the SDS for 37% Hydrochloric acid shown. Section 14.3 (ADR) shows the primary hazard for transportation by ROAD is transport hazard class 8. Table can be found online via this link: https://www.hse.gov.uk/cdg/manual/classification.htm

Note, biological materials e.g. bulk tissue, bones, organs etc. are disposed of via Clinical wastes. If a waste is classed as 'Miscellaneous dangerous goods', the SDS (section 14.2) will often specify the primary hazard. This is common for environmentally hazardous substances.

2. Hazardous waste consisting of several (mixed) hazardous substances:

For this type of waste the WM3 technical guidance by the environment Agency is used to determine if a waste is hazardous or not and if hazardous, which hazard statements apply. If the hazard statement number fits into a UN Class, the highest applicable UN Class will be the primary hazard for transportation (1 - explosives, 2 - gasses, 3 flammable liquid (e.g. H224, H225, H226) etc. - see table above). The second highest applicable UN Class may be the secondary hazard.

There may be hazard statements that apply but they do not fit into a UN Class in such case either use NCAD (Not Considered As Dangerous) if two or more statements apply (e.g. H315, H317, H318, H340, H351) or use NH (Non Hazardous) if no hazard statements apply. In such cases where the waste is NH, it may still be disposed of via hazardous waste e.g. waste containing trace heavy metals (ask the Chemicals Safety Advisor when in doubt).

Link here to WM3 - https://www.gov.uk/government/publications/waste-classification-technical-guidance

Click here an overview of the Hazardous Property Assessment (from WM3) 

 

Other Useful Information

Expand All

 

if you do not know the density, then set this to 1 - this may usually be okay for estimates

Example converting 1M Sulfuric acid to w/w%:

Gas cylinders are returned to the supplier e.g. BOC. This may not always be possible with speciality gases in small lecture bottles or from abroad in such instances they are disposed of via hazardous waste by filling in a waste form and email it to chemicals@materials.ox.ac.uk. Additionall the waste form should also include the following information: dimensions, weight and indication of the cylinder is full or empty. Always check with the supplier before arranging hazardous waste disposal.

It is difficult to dispose of non-hazardous items (such as gloves) contaminated with hazardous substances via hazardous waste as the level of contamination can be difficult to estimate. Unlike liquid waste where the contamination is 'evenly spread'. This may not be the same for contaminated non-hazardous items e.g. 1 contaminated glove in a container with 10 non-contaminated gloves may make the entire waste hazardous, even though the non-contaminated gloves are not hazardous. This is not permitted under the duty of care and this is why the waste disposal routes must be established before generating hazardous waste i.e. by completing a COSHH form.  

  1. Avoid contaminating non-hazardous items in the first place i.e. design/work out processes where this issue can be eliminated or reduced as much as possible – look into substituting for items which can be cleaned/decontaminated and reused e.g. use a tray instead of foil as underlay
  2. Decontaminate wherever it is possible. Examples:
    Inorganic acid on glove Wash gloves under tap water. Remove gloves and dispose of via general waste.
    Hydrofluoric acid on tissue paper Leave in a labelled, plastic beaker inside fume hood overnight or until it is completely dry. Dispose of via general waste
    Solvent on gloves or tissue Leave in a large beaker in fume hood. Dispose of via general waste when dry
    Sulfides or cyanides on gloves and  glassware Oxidize under alkaline conditions to sulfates or cyanates e.g. decontaminate using a bleach bath. Bath is disposed of via hazardous waste, gloves are rinsed and disposed of via general waste and glassware is cleaned and reused.

     

  3. Contaminated non-hazardous items may only be disposed of via hazardous waste if it is impossible to decontaminate and considered hazardous. This must be agreed in advance with the Chemical Safety Advisor and Safety Office. 

Safety Office: https://safety.admin.ox.ac.uk/hazardous-waste-a-z-summary-page

or contact the Chemicals Safety Advisor (chemicals@materials.ox.ac.uk)

Guides 

Please see below for specific information on disposal routes for different types of hazardous waste

Waste Disposal Instructions (main site)

Waste Disposal Instructions (Begbroke)

Hazardous Waste Summary (main site)

Hazardous Waste Summary (Begbroke)

If you find you are not sure or get stuck, contact the Chemical Safety Advisor on chemicals@materials.ox.ac.uk