Waste Management: Disposal of Biological Waste
Return to Waste Disposal - Introduction
Information on the principles and operation of autoclaves
is available elsewhere.
The department has central autoclaving and sterilisation
facilities.
Page Contents
Includes: Introduction | Waste disposal guidelines | Autoclave bags | Autoclave bins | Pipettes | Laboratory responsibilities in the autoclave area | Autoclave protocol for bags | Autoclave protocol for autoclave bins | Protocol for recording autoclave runs | Summary table
Introduction
The safe transport of infectious waste begins at the point of origin, ie. in the laboratory that it is generated in. It is the responsibility of all laboratories to ensure that infectious waste is placed in the correct container (autoclave bin or bag) and that inappropriate materials and general waste are not.
The Media Preparation Unit (Media Room) is responsible for the processing, recycling or disposing of all microbiological waste generated within the Department. Individual laboratories bring their waste and specialised items like pipettes, tissue culture bottles, tips, etc to designated areas for sterilisation and further specialised processing. All biological waste must be double-contained for transport to the Media Preparation Unit. The outer (secondary) container must be non-breakable and sealable to prevent the escape of hazardous materials, and labeled with the Laboratory Name.
AT ALL TIMES, PERSONAL PROTECTIVE CLOTHING MUST BE WORN WHEN DEALING WITH INFECTIOUS MATERIALS AND AUTOCLAVES.
Autoclave Bags
Materials allowed to be placed in an autoclave bag are:
- plastic Petri dishes
- disposable plastic items: microtitre trays, microcentrifuge tubes, etc
- contaminated paper
Materials NOT ALLOWED in an autoclave bag are:
- Pasteur pipettes, microscope slides, sharps, plastic pipette tips (may puncture bags!)
- recyclable glassware or plasticware
- non-contaminated paper
All autoclave bags are to be closed with a RUBBER BAND before being transported to the autoclave area or room. Autoclave bags are not to be closed with reams of autoclave tape or sticky tape.
Reason: Some one has to reopen these bags before placing them in the autoclave. Closed bags cannot be sterilised effectively as the steam does not penetrate. Autoclave bags closed with rubber bands are much more easily opened without creating aerosols. Scissors or other means are required to be used for autoclave or sticky tape and then must also be autoclaved.
Sharp objects must not be placed in autoclave bags as this will cause them to leak! This should be obvious but it does occur. Contaminated leakage over trolleys and floors is very difficult to clean up.
Autoclave Bins
All bins are to have a gussetted autoclave bag as a plastic liner.
NO bin is to be used without this liner.
Reason: Autoclave bins leak and cannot be mended.
Autoclave bins MUST NOT BE OVERFILLED and must not have 'bits and pieces' protruding above the rim. If the autoclave bin drawer does not close then it won't fit in the autoclave either.
Reason:The drawer size matches the height of the autoclave trolley inside the autoclave. Overfilled bins do not fit and someone will have to transfer bin contents to another bin. also applies to protruding bits. These break off as the bin is slid down the autoclave tray to the back of the autoclave. These broken pieces can at worst fly off into people's eyes, penetrate bare skin or create havoc with the autoclave by blocking the steam exit valve.
In some instances even if the autoclave bin is not overflowing, it is still too full. Filling an autoclave bin to the top with small objects ie. Bijou bottles should also not occur. Autoclave bins should ever only be half filled if only bijou bottles are discarded.
Reason:The density of material that the steam has to penetrate is too deep and trapped air at the bottom of the bin cannot be removed.
- Bijou Bottles - only half fill the autoclave bin
- Slides, Pasteur pipettes, - only half fill the autoclave bin
Separation of materials for recycling or disposal begins to occur at the laboratory level Each laboratory has a number of autoclave bins per draw. Each bin should be labelled for a particular type of contaminated material.
- Recycled glassware or plastic ware.
- Fragile glassware from robust glassware
- Disposable items, petri dishes and broken glassware
Materials which may be placed in the autoclave bins are:
- all recyclable glassware and plastic ware
- all pasteur pipettes (LAYING FLAT IN THE TIN with no protruding pieces)
- all sharp objects, slides, contaminated broken glass, tips
- petri dishes if no autoclave bag is available.
- contaminated materials inappropriate for the autoclave bags.
Materials which may NOT BE PLACED in autoclave bins:
- chemical bottles or winchesters
- non - contaminated materials and paper
- non - contaminated broken glassware
- concentrated acids or bases
- flammable materials
When preparing to transfer the bins to the autoclave room, the lining autoclave bag must be taped shut but when the bins are placed in the correct spot in the autoclave area or room the lining bags must be reopened.
Reason: The inner contents of autoclave bins are the most difficult to sterilize effectively. When the autoclave bin lining is sealed shut it is extremely difficult for the steam to penetrate at all and any trapped air cannot get out. This results in a failure to sterilize all materials in the bin. This places all the recycling staff at risk.
A substantial piece of autoclave tape must be applied across the corner of the bin.
Reason: This will allow Media Preparation Unit staff to have verification that this bin has been autoclaved and can proceed to wash up.
Any spillages that occur before, during and after transfer of infectious materials whether in the laboratory, the corridor or the autoclave room must be immediately cleaned up by the responsible laboratory. It is recommended that 'Inhibac' be used.
Pipettes
Pipettes can be sterilised in their upright containers. These must have autoclave tape across the top to show whether they have been autoclaved or not.
Metal trays are available in the Autoclave Room for pipettes to be autoclaved. These are usually pipettes that have been sitting in disinfectant. Carefully place the pipettes in the trays ensuring that they are laying flat. Do not add soap. Ensure that all the pipettes are covered with water. These pipettes go to washup for recycling into the general use unless specified. To get them returned to your laboratory they will need to be labelled.
Reason: Pipettes not covered by liquid in the autoclave, develop a film of dried 'muck' on the inside and cannot be cleaned.
Laboratory Responsibilities in Autoclave Area
- All infectious waste or materials must be placed in the correct area in the ground floor autoclave room. The correct area is labelled. See Mud Map included in documentation. Two trolleys in the little infectious waste room are for autoclave bags and tins.
- Please place all material on the trolleys. If they are full, waste may be placed on the floor but ensure that the walkway is not closed off.
- DO NOT PLACE TINS ON TOP OF ONE ANOTHER! The contaminated contents
of one tin is then spread all over the bottom of the tin placed on
top! If the trolley is full, tins must be placed on the floor. Just
because trolleys may be full and the area congested is not an excuse
for bad microbiological practices.
The only exception would be if the tin had a lid on it. Then another tin may be placed on top as long as there is no chance of the top tin toppling over. - Autoclave tins have preference on the trolleys. Bags preferably can be placed on the floor.
- Ensure that all lining bags in tins are fully open and that a substantial piece of autoclave tape is placed across the corner of the tin so that it is easily seen. Not on sides of tins or 1 cm bits stuck anywhere.
- If the tin is overfull please transfer material to another tin. Each laboratory knows what is in their tins and the risk involved in moving material. Therefore it is their responsibility to transfer material and not some unknown person. The tins should not be overfilled in the first place!
- NEVER PLACE CONTAMINATED MATERIAL IN THE DESIGNATED STERILE ZONES. Do not place materials for sterilizing on the desk. This is a work bench and not a drop zone. The designated sterile area is beside the autoclaves near the hand basin.
- There are plenty of spare autoclave tins and liner bags in the autoclave room. It is a matter of helping yourself.
- All other materials that need autoclaving and recycling (flasks, containers, animal boxes, other goods etc.) must be clearly labelled with the laboratories name. They should be placed on the labeled metal shelves. When sterilized, the laboratory must come and collect their materials. Some materials can sit in the autoclave area for weeks and months. The area is too congested to be storing people's junk. Come back for it! Take it or media will dispose of it!
Autoclave Protocol for Bags
- Wear disposable gloves when handling and processing autoclave bags.
- Remove rubber band from throat of bags.
- Place bag on autoclave trolley tray and fold INWARD the sides of the bag so that mouth of bag remains open. Bags collapse when autoclaved and for steam to enter it must have access. Folding down the sides makes them more rigid and they will possibly remain upright.
- Remove disposable gloves and leave them inside the autoclave.
- Initiate sterilisation cycle. 121ºC for 90 minutes.
- When complete use rubber gloves to remove bags from the autoclave. Agar is very hot and will splash out of collapsed bags. Be careful of your feet and clothes. Immediately place bags into the green waste bin placed beside the autoclave.
- Wash the autoclave out with hot water giving particular attention to the drain as agar will set in it and block it, also small bits of glass will block it.
- Ensure water on the floor goes down the drain.
- NOTE: NEVER PUT BAGS IN AS LAST LOAD OF DAY (unless you intend to be around to empty it) as this will most definitely block the autoclave overnight.
Autoclave Protocol for Autoclave Bins
- Wear disposable gloves when handling tins.
- Ensure that all liners are fully open and autoclave tape is clearly displayed.
- Place tins on autoclave trolley in autoclave. There are two tiers available in large autoclave, single tier in small autoclaves.
- Bags and tins may be autoclaved together. See above protocol for bags.
- Leave gloves in autoclave.
- Initiate sterilization cycle 121ºC for 90 minutes.
- On completion of run, remove tins and place them in the designated sterile area.
- Those items that a clearly non-recyclable must be disposed of in the green waste bins beside the autoclave. (Note: Tip all liquid down the sink with copious amounts of hot water before disposing into green bins. Green bins leak dramatically.)
- Lightly rinse autoclave with hot water. This stops chloride solutions and such like from 'eating' away the autoclave.
- If green bin is full, please please take it outside the loading bay and replace it with an empty one.
Protocol for Recording Autoclave Runs
- Each run of the autoclave must be recorded. This is a requirement for Safety Map, NATA Accreditation, ISO9000 Certification and Good Common Sense.
- A clipboard is provided to record a number of parameters of each run. These parameters are: Date, Items in autoclave, sterilisation time and temperature, time of commencement of run and completion, person operating autoclave or doing this run. It also has columns for recording if the autoclave tape changed colour, that the thermolog (if used) was correct for this run and a thermocouple chart recording observation (not available at present).
- Please record all relevant information on the clipboard. When the sheet is full, start another one.
- Thermologs are available in the autoclave area. They can be found near where the spare tins and autoclave bags are kept. They are to be used with every run that is not a waste run. Ie: for media, containers etc. Results are to be recorded on the clipboard and then the Thermolog may be discarded.
Biological Waste Summary Table
Download Biological Waste Summary Table (pdf) or Waste Summary Table - all categories (pdf).
Item |
Designated AreaValid from 8/9/08 until further notice |
Container |
Comment |
| Pasteur pipettes and broken glass pipettes | Room 3.22, or |
Sharps container (preferred) LYING FLAT in lined autoclave tin to Autoclave Room |
Additional information - see above |
| Non-Recyclables e.g. plastic pipette tips, Petri dishes, paper, microtitre plates, microfuge tubes |
Autoclave Room, Ground Floor | Autoclave bag, or lined autoclave tin Autoclave bags must be transported in a sealed, non-breakable container |
No liquids, sharps, chemicals or empty reagent bottles in autoclave bags Additional information - see above |
| Recyclables e.g. glass bottles and test tubes, Dreyers |
Autoclave Room, Ground Floor | Lined autoclave tin | No corrosive or toxic chemicals Additional information - see above |