MORETON BAY COLLEGEScience Department.

MICROBIOLOGY LABORATORY POLICY AND PROTOCOLSDownloaded from seniorbiology.com/eei.html

HAZARDSRoutes of exposure to microorganisms may occur via skin abrasions, cuts or puncture wounds, inhalation of aerosols, or ingestion via contaminated hands or materials. Exposure may involve the individual staff or students using the micro-organisms, other staff and students using the same laboratory or work area, cleaning staff, or the wider community. The outcome following exposure depends on the pathogenic level of the microorganism involved, the exposure level, and the route of exposure.

RISK ASSESSMENTWhenever microbiology is studied there are potential risks from the hazards of infection. It is through the establishment of correct and appropriate protocols and the strict adherence to these procedures which enables students and staff to work safely with microorganisms. This includes selecting the appropriate level of practical activity for the student age group, clear safe working protocols (SOP’s), the facilities available, and the level of training and experience of the teacher and the laboratory technician.

Standard operating procedures (SOPs) must be documented within a risk assessment for all activities undertaken and these must be strictly adhered to. Procedures should be such that the risk of contamination to: the air, to laboratory benches and furniture, to the student and staff working with the bacteria, to other students and staff, or to the wider community and the environment, is suitably reduced. These procedures should include the equipment and facilities required in preparation, experimental techniques, and clean-up and disposal. The procedures must also include emergency plans for spills and first aid. These are outlined at the end of this document.

GENERAL CONTROL MEASURES.Each of these aspects must be considered in the risk assessment.

Student age and maturity It is important that the teacher is confident that the students planning on working with microorganisms will be able to have a full appreciation for the risks and be disciplined in following the standard operating procedures.

Experience It is important that the teacher and the laboratory technician has an appropriate level of competence in preparation, sterilization, and disposal of materials. (See detail below under - Appropriate Activities for Various Year Levels)

High Risk Persons. Persons can be immuno-compromised, immuno-suppressed, due to a medical condition or medical treatment they are receiving. Others may be unduly vulnerable to infection such as persons who are diabetic and pregnant women. These people (students or staff) need to be identified and then managed appropriately. The management should be consultative and based upon professional medical advice.

Selection of MediaStandard nutrient broth or nutrient agar is sufficient for school culture work. [Media designed to select pathogens (e.g. blood agar, McConkey etc.) must not be used].

Selection of BacteriaThe College will only use Risk Group 1 micro-organisms (as defined in AS2243.3 Safety in Laboratories – Microbiology Aspects and Containment Facilities) – being those that pose low individual & community risks. These are microorganisms that are unlikely to cause human, plant or animal disease. The organisms for use in the College are limited to bacteria. (see appendix 1). Viruses and fungi will not be used. The College will only purchase these micro-organisms from Southern Biological Supplies which has been deemed a reputable supplier. Other suppliers may be considered at the discretion of the Laboratory Technician and Laboratory Manager.

Potential to be PathogenicAll microorganisms shall be treated as potential pathogens. Even microorganisms not normally associated with human diseases, are ‘opportunistic’ pathogens and may cause infection in the young, the aged and in immune-deficient or immune-supressed individuals. In addition, samples may become contaminated or may mutate. Contain all organisms at each stage of the procedures as if they were of higher risk.

Size LimitationsCultures should be kept to the minimum size and number required to achieve meaningful results.

Incubation TemperatureThe incubation temperature should be restricted to an upper limit of 30OC to reduce the danger of isolating pathogens adapted to human body temperature. Anaerobic conditions should also be avoided for the same reason.

AerosolsAerosols (particles of liquid containing microorganisms suspended in the air) can easily contaminate the laboratory if procedures are poor. Care must be taken when flaming loops, opening bottles, using pipettes and any other procedure that may produce aerosols. Spills may also cause aerosols. (See sections on Spills and First Aid) If there is clearly an identified risk of a procedure producing aerosols, then the technique should not be used, or the work should be carried out in a biological safety cabinet.

Culturing from the EnvironmentThe College does not permit students to culture organisms taken from the environment. This includes samples from bodies of water, soils, atmosphere, toilet areas, door handles etc. If microorganisms are cultured from the environment there is the possibility of isolating unknown high risk pathogens.

Extra Laboratory Rules for Microbiology:

Avoid habits of putting hands or objects anywhere near the mouth of eyes. Teacher should warn students pro-actively.

Staff & students must always wear specific laboratory coats/aprons while in the laboratory. These coats/aprons are provided by the College and will be stored on hangers in the laboratory for duration of project of work, after which time they will be properly laundered. The laboratory coats must not be worn outside the laboratory.

All cuts or broken skin must be covered by a water resistant dressing eg a Band-Aid and gloves. Teacher will ask all students prior to starting work each day.

Benches should be clear of all non-essential materials including books and notes. Following any practical work with the microorganisms, benches should be wiped

with a suitable disinfectant eg. 0.1% solution of sodium hypochlorite (available Cl), or 70% alcohol. Wearing gloves, spray disinfectant over bench surface, wipe off with cloth and dispose.

Teacher must ensure all hands are washed with soap and water at the designated hand wash sink before leaving the laboratory. Hands must also be washed after removing gloves, following clean-up of a spill. (See section on Correct Hand Washing Techniques)

APPROPRIATE ACTIVITIES FOR VARIOUS YEAR LEVELSYear 7 Only microorganisms with little, if any, known risk should be used. e.g. observationof moulds, yeasts and algae. These should be observed in closed containers that thestudents cannot open. No special training is required for the teacher or laboratory technician.Years 8-10At this level, culturing techniques with known organisms from reputable suppliers. All petri dishes must be sealed following inoculation & during examination. At this level, both the teacher & the laboratory technician require a working knowledge of aseptic technique, safe disposal technique and must be able to recognise contamination. This level of knowledge would be acquired from a short in-service course in microbiology.Seniors - Year 11-12At this level, application of inhibitory substances to cultures and sub-culturing and transfer procedures using known organisms are appropriate. If carrying out sub-culturing, both the teacher & the laboratory technician require good aseptic technique. This can only be provided through training & practice extending beyond the level of a short course.

Work should not be carried out by non-specialised staff or if appropriate facilities are not provided.FACILITIESMBC has a modern Microbiology Laboratory [R6 ] designed to meet requirements of PC2 (physical containment level 2) as specified in AS 2243.3. This exceeds that required to work with risk group 1 microorganisms. The facility offers protection with: Fully coved seamless vinyl flooring which reduces crevices and ledges which are

hard to disinfect. Easily cleaned bench surfaces and floor area with minimal fixed under bench

cabinetry or cupboards. Sensor operated tap at hand wash basin. Negative pressure air flow system. Smooth water impervious ceiling tiles. Autoclave in adjoining preparation room.

Work with the risk group 1 micro-organisms must only be carried out in the Microbiology Laboratory.

PREPARATION & STERILISATION OF EQUIPMENTSterilization. (killing of all microbiological life including bacterial and fungal spores)The College uses a bench top autoclave which is located in the adjoining preparation room to the microbiology laboratory. This is operated only by the laboratory technician, who had been trained in its operation and will follow the safe operating procedures.The Laboratory Manager shall ensure the autoclave is regularly maintained. Items should be sterilised at 121 OC and 15 psi. (or 103kNm-2) for 15 minutes.As a back-up to the autoclave the use of a pressure cooker following established safe operating procedures is possible, keeping in mind this will only disinfect and not sterilize, although this is still adequate for the level of work at MBC. Refer to Standard operating procedures for more detail and instruction on autoclave use.

Disinfecting. (Likely to kill all but the most resistant microorganisms such as Tetanus bacterial spores).

Disinfectants The following 2 disinfectants are suitable for use on benches, surfaces and equipment. They should be applied as a spray according to the standard operating procedure.

Alcohols (good activity on bacteria, and fungi but less on viruses and poor activity on spores. 70% ethanol is rapid acting and dries quickly. (100% ethanol is NOT effective) 60-70% Isopropyl alcohol (Propan-2-ol).

Sodium Hypochlorite (good activity on bacteria, fungi and viruses, but less activity on spores).They must be prepared fresh daily from the concentrated stock solution to ensure the correct level of available chlorine.

1% available chlorine for spills,

0.25% for discard jars, 0.1% for cleaning benches, and 0.05-0.1% for equipment and instruments.

The following disinfectant may be used for hands and skin.

Chlorhexidine (good activity on gram-positive bacteria but less activity on gram-negative bacteria, viruses and fungi and poor activity on spores).

It has low toxicity and irritancy and so is a good antiseptic. 0.5% for face - 4% for other skin.

The Safety Data Sheet for the disinfectants used must be consulted for appropriate technique, protective equipment and ventilation requirements.

SAFE BACTERIA HANDLING TECHNIQUESThese procedures are for use by the laboratory officer, teachers and students.Teachers should fully explain and demonstrate all techniques that the students willuse, giving particular attention to safety and good aseptic technique.Students must have been be taught good aseptic technique prior to experimentation.

Techniques - safe techniques for the following are described in the Standard Operating Procedures section below.

Plating Broth Cultures Using Wire Loops. Preparing a Bacterial Lawn for Antibiotic Discs. Observation of Plates Microscopic Examination of Bacteria

Disposal and Clean-up.The most important bacterial infection control is that of always carefully following, systematic and pedantic technique. This applies to the handling of equipment used, disposal of consumables and cultures themselves, and personal cleanliness. Detailed procedures for the following cleaning and disposal tasks are outlined in the Standard Operating Procedures section below.

General Clean-up Glassware Broth Cultures Petri Dishes. Incubator.

References: Microbiology – Safety Considerations 1999Sheryl K. Hoffmann, B Sc., Grad Dip. O. H., MSIA Concordia College Laboratory Officer, Concordia College, 45 Cheltenham St, HIGHGATE SA 5063

Standards Australia, AS2243.3- 2002 Safety in Laboratories. Part 3. Microbiological Aspects and Containment Facilities.

APPENDIX 1

List of Bacteria Risk Group 1

Acetobacter aceti Agrobacterium tumefaciensBacillus subtilis Chromobacterium lividumChromatium species Erwina carotovora (=E. atrospetica)Escherichia coli * Lactobacillus speciesMicrococcus luteus (=Sarcina lutea) Photobacteium phosphoreumPseudomonas fluorescens** Rhizobium leguminosarumRhodopseudomonas palustris Spirillum serpensStaphylococcus albus (epidermidis)** Streptococcus lactisStreptomyces griseus Vibrio natriegens (=Beneckea natriegens)

Additional information for consideration when completing the risk assessment. * Some strains have been associated with health risks. Reputable suppliers will ensure that acceptable strains are provided.** These organisms have been known to infect debilitated individuals and those taking immunosuppressive drugs.

The following microorganisms have previously been used in schools but are no longer considered appropriate. These must not be used at the College.

Aspergillus nidulans Aspergillus niger Chromobacterium violaceum Clostridium perfringens (welchii)Penicillium chrysogenum Penicillium notatumPseudomonas aeruginosa Pseudomonas solanacearumPseudomonas tabacci Serratia marcescensStaphylococcus aureus Xanthomonas phaseoliList taken from: Department of Education and Science, 1985, Microbiology: An HMI Guide for Schools and Non-advanced FurtherEducation, Her Majesty’s Stationery Office, London, pg 20 /21.

STANDARD OPERATING PROCEDURES

STERILIZATION.Autoclave.The College autoclave is a bench mounted Siltex, with steam generating water tank on board. Autoclave is located in Biology prep room adjoining microbiology lab. This model will autoclave at 140oC at a pressure of 15 bar or 220KPa, while 120oC is sufficient for effective sterilization of any risk group level 1 Bacteria. Ensure autoclavable bags used are rated to 140oC and not just 120oC, otherwise they will melt. Users must be suitable trained to use the autoclave by the Laboratory Manager. The autoclave should be maintained regularly.

Autoclave Operation1. Check the internal water reservoir is near to full. (port on top back left of unit).

If necessary add tap water. 2. Fill the sterilizing chamber with water from the internal reservoir by pulling

down on the fill / vent lever (front top left). The chamber is sloped backwards so fill until water line is 5omm from the front edge.

3. Load material to be sterilized into tray which will sit just above the water line.4. Push the door closed and manoeuvre until the safety locking pin can be

securely located into place. Then turn the locking handle clockwise until hand tight.

5. Set the timer dial to 20 minutes, and turn power on at the wall.6. To start - push the switch at bottom to the ‘on’ position (left). The yellow LED

should light up. 7. The autoclave now be starting to heat the water and build pressure. Do not

touch any controls now until cycle finished. 8. It will take approximately 15 minutes for the temperature and pressure to be

reached at which time the sterilization period (20 minutes) will commence. (The green sterilizing LED indicator should light up at this stage).

9. Monitor the gauges to check that 140oC and 220 – 230KPa are holding during the cycle.

10.The buzzer alarm will indicate when the 20 minutes is completed.11.Slide the switch at the bottom to off. 12.Release pressure gradually by gently and intermittently pulling down on the

fill / vent lever (front top left). Pull the lever down briefly, release, pull down again, release, etc repeatedly until the pressure gauge indicates zero. You will also hear the steam being released back through the water reservoir until the pressure is fully released.

13. It will now be safe to open the chamber door by winding the handle anti-clockwise. If the handle will not turn then there is still pressure in the system.

14.Remove the locking pin and carefully open the door to remove autoclaved materials. MIND they could still be hot - it is a good idea to just slightly open the door and allow to cool before handling.

Materials in autoclave Do not wrap or cover items with foil as this impedes the steam penetration. Schott bottles should have lids on loosely to allow steam inside.

Special autoclave bags rated to 140oC available from medical suppliers are to be used.

Extreme care must be taken when sterilising liquids, the exhaust valve should notbe opened quickly or bottles may explode.

Siltex AUTOCLAVE

Sterilizing Pipettes.Prior to use: Pasteur pipettes should be plugged with non-absorbent cotton wool and any protruding fibres burnt off. They are then wrapped in brown paper or foil, alternatively they can be placed in pipette canisters or test tubes and the ends of the test tubes sealed with paper or foil and masking tape. They can then be sterilised in a dry heat oven at 160 OC for at least 1 hour, allowing adequate time to reach the correct temperature. Temperatures over 170 OC will char brown paper and cotton wool.Similarly graduated pipettes may be plugged, wrapped and sterilised.

After use, pipettes should be immediately immersed in a container ofdisinfectant and sterilised before disposal or washing. (A 600 ml tall beaker or a 2Lplastic measuring cylinder makes a good discard jar.)

Sterilizing SwabsPrior to use: Cotton buds can be wrapped in brown paper and autoclaved or wrapped in foil/ brown paper and dry heat sterilised as above. Some cotton buds are treated with anti-microbial agents and it is usually more reliable to use hospital grade swabs, available from medical supply companies.

After use, swabs should be immersed in a container of disinfectant andsterilised before disposal.

Water chamber port

Pressure gauge 220KPa

Timer and control panel

Fill/ vent lever

Chamber door Door locking pin

Sterilising Test Tubes & Other GlasswarePrior to use: Test tubes and other glassware should be plugged with cotton wool and capped with foil or brown paper, and then sterilised by dry heat as above. McCartney bottles and Schott bottles do not require cotton wool plugs and should just have their lids screwed on firmly and then released a quarter turn, prior to sterilisation.After use, glassware should either be placed in disinfectant or autoclaved prior tocleaning.

Sterilising LoopsWire loops for transfer of bacteria can be made from 24 swg nichrome wireheld in chuck needle holders or glass tubing that has had the wire inserted and theneck sealed closed by the application of heat.Loops are sterilised by heating to red hot in a Bunsen flame. Safety - Flame heating loops carrying a culture may splatter and produce aerosols or eject clumps of microorganism on the bench. To avoid this, loops should be drawn slowly from the cooler to the hotter part of the flame. The loops should also be cooled before use (e. g. on a vacant part of the agar plate) to prevent killing the bacteria that you wish to culture. Alternatively the loop may be dipped in 70% alcohol and then flamed.Loops are sterilised just prior to and immediately following use.

Alternatively - plastic commercial loops may also be used which are placed into a designated bag / container ready for sterilizing in the autoclave.

Sterilising spreaders & forcepsSpreaders are L-shaped glass rods used to spread a liquid culture evenly over a petri dish. Spreaders and forceps are sterilised by dipping them in alcohol and lighting the alcohol in a Bunsen flame. The alcohol is allowed to burn off before use. Spreaders may break if held in the Bunsen for too long.Spreaders and forceps are sterilised just prior to and immediately after use.

PREPARATION OF AGAR PLATES

The College will generally purchase pre made agar plates form Southern Biological. However the method for preparation of the plates is outlined below.

Following the instruction on the jar, (grams per litre) the powdered agar media is added to water in a large conical flask. It is heated until the agar dissolves at 95 OC. (This is best done in a water bath e.g. a saucepan of water on a hotplate.Alternatively be sure to mix the contents well or uneven heating may crack theflask. The agar solution is then poured into Schott bottles and the lid closed firmly then released a quarter turn. Alternatively the agar may be poured into conical flasks and plug with cotton wool and cover with brown paper. The bottles/flasks are then sterilised in an autoclave or pressure cooker for 15 minutes at 121 OC & 15 p.s.i. (a microwave method for sterilisation is also available)

The agar is allowed to cool to 50-55 OC. (NB: Agar will not set above 42OC) Plastic disposable petri dishes are lined up on the bench, in a draft free room. NB: It is not recommended that glass petri dishes be used. Air-conditioners, fans and fume cupboards must be turned off, windows and doors closed and foot traffic restricted, to reduce the chance of contamination to plates while pouring. The bottle/flask is unscrewed or unplugged and held at an angle. The lid from a petri dish is lifted just enough to allow the agar to be poured in. This is repeated for the other dishes until all the agar is used.Approximately 25 ml of agar per dish is ideal. The agar is allowed to set beforerepacking in plastic bags and storing in the fridge in an inverted position untilrequired. (see Figure 1)The alternate recipe for Nutrient Agar preparation, used in the Microwave Method,

PLATING BROTH CULTURES USING WIRE LOOPS.The lid/plug of the culture bottle/flask is held in the little finger. (never placed on the bench) The bottle's neck is then passed through a Bunsen flame. (See Figure 3)A wire loop is heated to red hot in the Bunsen flame and then dipped into the broth culture carefully. Splattering may occur if the loop is not allowed to cool slightly before use. A loop full of culture is transferred to the agar plate. The loop is spread over the surface of the plate. (see Figure 4) If individual colonies are required the pattern illustrated in Figure 5 is used. The loop is then re-flamed and the neck of the culture bottle is passed through the Bunsen flame before the lid/plug is re-fitted.

Figure 3 Flaming the Neck of a flask & Holding a Cotton Plug with the Little Fingers

Sterile Cotton Buds. If you are using a pre-sterilized cotton bud, then you will clearly not be flaming the bud, but you still flame the neck of the flask containing the culture.

Fig 4 General Spreading Pattern Fig. 5 Spreading Pattern for Individual Colonies

PREPARING AN ANTIBACTERIAL LAWN FOR ANTIBIOTIC DISCS.

The lid/plug of the culture bottle/flask is held in the little finger. (never placed on the bench) The bottle's neck is then passed through a Bunsen flame. (See Figure 3) A pipette is partly removed from its packaging and a teat attached. 3-4 drops of a liquid culture are removed from the culture and introduced into the petri dish. A sterile spreader (cotton bud) is then used to spread the culture evenly over the agar. An antibiotic disc is removed from its packet with sterile forceps and carefully positioned on the agar surface using sterile forceps.Similarly, other antiseptics or test solutions may be tested, by placing a small discof filter paper that has been dipped into a test solution onto the surface of the agarspread with a bacterial lawn.

TAPING AND INCUBATIONFollowing inoculation, the petri dish base and lid should be taped together as shown in Figure 6. Petri dishes should not be completely sealed as this may produce anaerobic conditions and the selection of pathogens.

Fig 6. Taping petri dish lid after inoculation.

Plates should be labeled on their base with contents, date and student name. Ideally this should occur prior to inoculation.Plates should be incubated in an inverted position (that is agar side upwards) toprevent condensation falling onto the colonies and contaminating them. Plates should not be piled high otherwise they may fall spreading their contentsover the bench. Dish racks or baskets should be used or the plates taped togetherwith masking tape.

OBSERVATION OF PLATES Petri dishes should generally be observed without opening the lid.

[Yr 11-12 may open the lids but only when necessary to subculture the bacteria or for susceptibility testing, and only with samples of known “safe” bacteria, as per list in appendix 1.] However a specific risk assessment must be completed and head of Science approval sought for this process before attempting.]

SERIAL DILUTIONS Use only the sterile disposable pipettes provided and dispose of into autoclavable bag on tripod on bench. Do not place on bench after use.

MICROSCOPIC EXAMINATION OF BACTERIA. (Only to be attempted after significant skill and competence achieved, and should be carried out in Biological Safety Cabinet). This procedure should only be carried out at Year 11 – 12 level when the students have been taught and developed good aseptic techniques. A special risk assessment would need to be completed and approval of the head science required before attempting this technique.

Bacteria may be transferred to a microscope slide from an agar plate using a wireloop or from a broth culture with a loop or pipette. If from an agar plate thebacteria are mixed with the drop of sterile water, on the slide, using the loop. Thebacteria are spread into a very thin film using the end of another slide as for bloodsmears. This film is then held high over a Bunsen flame to dry. It must not beallowed to steam and hence produce aerosols. If the smear is not dried within a few seconds it is too thick and the bacteria will clump together and distort as they dry and fix onto the slide. All contaminated items must be immediately placed in disinfectant. The fixed bacteria may then be stained using a Gram staining technique.A safer method of viewing bacteria on the microscope is to use yoghurt or Yakult instead of the broth culture. This is suitable for Yr 8-12.

Other Practical ExperimentsOther practical procedures (e.g. serial dilutions) may be attempted by senior biology students, when students have developed good aseptic techniques. Standard procedures for such procedures should be sourced, assessed, documented as a risk assessment and followed carefully. Head of Science approval required.

Maintenance of Pure Bacteria StocksBroth cultures may be stored in the fridge for several weeks.For short term storage petri dishes (or slopes) are preferred. When cultures aremaintained in the short term, a subculture should be plated out before starting a newseries of experiments and examined for signs of mixed growth, indicating that thestock has been contaminated. Such contaminated broths should not be used.

The long-term storage of cultures in schools is not recommended and as such will not occur at MBC.

DISPOSAL AND CLEAN-UP

General Clean-upAll contaminated items should be decontaminated prior to reuse or disposal. Carefully organisation is required, to minimise re-handling and prevent the spread of contamination. This can be achieved by lining special containers with autoclavable bags for collection of items to be autoclaved. (NB: Glad oven bags make a good substitute for autoclave bags).

Autoclavable bag in tripod frame on bench All material waiting to be decontaminated must be held in a secure location away from student areas or where it could be accidently disposed of by cleaners.

GlasswareItems for re-use should be immediately placed in disinfectant and soaked according to the manufacturer's instructions, prior to washing. (e.g. 0.25% Sodium Hypochlorite solution, soaked overnight)

Broth CulturesBroth cultures should be sterilised by either autoclaving or addition of a suitable disinfectant. (e.g. enough sodium hypochlorite to bring the culture to 1% available chlorine solution, left overnight). Once sterilised it may be poured down the sink.

Petri Dishes.When disposable petri dishes are no longer required they should be placed in an autoclavable bag for sterilisation before disposal. Once the bag is closed it should not be reopened to add additional plates as this may produce high level of aerosols, and hence contamination.A pressure cooker or microwave may also be used to disinfect petri dishes prior todisposal. Only a laboratory microwave, not used for food, should be used. If none ofthese methods is available, you must make arrangements with a licenced prescribedwaste removal company, for safe disposal. It is not permissible to discard petridishes into general or industrial garbage without prior sterilisation.

Incubator.Following use the incubator must be thoroughly cleaned and disinfectedwith an appropriate disinfectant. (eg. 0.1% available sodium hypochlorite or 70% ethanol ).

Benches.70% ethanol will be prepared and stored in a properly labelled spray bottle/s and held in the preparation room. Following each class using bacteria, the laboratory technician or teacher will spray the benches with the 70% ethanol and wiped clear with paper towel. Care must be taken by the person cleaning not to create aerosol of sodium hypochlorite at the breathing zone. The paper towels used for this may be disposed of in normal bin.

Correct Hand Washing TechniquesFacility. Use only the hand basin with the sensor operated tap near the laboratory door. Liquid soap dispensers will be used. Neutral pH, antibacterial soap will be used. The dispenser must be cleaned and dried prior to refilling.

Washing technique. Wet hands thoroughly and lather with antibacterial neutral pH soap, vigorously rubbing hands together for at least 10-15 seconds. Wash all parts of the hands, including back, wrists, between fingers and under fingernails. Rinse well under running water. Pat hands dry using disposable paper towel. To minimise irritation and dryness a suitable hand cream may be used.

SPILLS Students must be taught to report all spills to the teacher. Only the teacher or laboratory technician shall clean up such spills. If the spill is large or has caused a lot of splashing, aerosols ‘may’ have been produced and the room should be evacuated for 30 minutes. When cleaning spills disposable gloves must be worn.Spill Kit - A spill kit should be prepared prior to starting microbiology practicals, and be readily available. It should include all items required to clean up a spill, including disinfectant, paper towel, gloves and plastic bags and containers for disposal.

Spills on the BodyThe teacher must be informed immediately. Contaminated clothing should be removed and the affected area washed vigorously with soap and water. Medical attention may be sought if required. Any such incident must be recorded as an accident / incident on the MBC form. Contaminated clothing must be disinfected before washing.

Liquid Spills Liquid spills should be covered with paper towel soaked in disinfectant (e.g. Sodium Hypochlorite with 1 % available chlorine) for at least 20 minutes. The paper towel should then be placed in a plastic bag for disposal. The area should be cleaned with fresh paper towels soaked in disinfectant. Large spills may require the use of spill-control pillows or similar. These must be disinfected prior to disposal.

Contaminated Broken Glassware: Contaminated broken glassware should neverbe picked up directly with the hands. It should be cleaned up using aids such asbrush and dustpan, forceps or cotton wool swabs. Follow the procedure for liquid spills. All aids used in clean-up must also be disinfected following use, using 1% sodium hypochlorite.

FIRST AID

Cuts and Puncture Wounds from Contaminated Sharps.Immediate first aid must limit contamination to the wound and to the first aider. Any cut or puncture wound, caused by contaminated glass or sharps, must receive immediate medical attention. The student or staff member should go immediately to the Health Centre for appropriate disinfection, and follow the nurse’s advice.

Existing skin wounds. Minor cuts and abrasions which provide routes for infection from contaminated surfaces should be adequately covered with water proof band aides, prior to commencing any practical work.