Making and recording risk assessments in school science The legislation

Transcription

1 Making and recding risk assessments in school science The legislation Under various Regulations ( COSHH, The Management of Health and Safety at Wk, and others) the employer is required to undertake a risk assessment f activities done and materials used as part of the employer s wk. The significant findings of any risk assessment must be recded and employees need to follow the conclusions. Communication is often by the employer providing the employee with a copy of the written risk assessment. An employer may provide model ( generic) risk assessments. In school and college science and D&T, most employers provide model risk assessments produced by CLEAPSS. Befe undertaking an activity as part of wk, an employee must consult relevant model risk assessment(s). The employee should adjust adapt the outcomes of the model risk assessment to meet the needs of their individual circumstances. Risk assessment Risk assessment describes a process and an outcome. A thinking process At all stages individuals must consider the risk assessment and its implications. In science this may include trialing a procedure. The written recd that comes from that process The process Identify the hazards Page of 5 The written recd is both f communicating the thinking to others and f an individual end-user to recd the particular, and significant, outcomes of her/his own adaptations to a model risk assessment. This last point allows others to recognise that the thinking has taken place at a sufficiently specific level of detail. From warning signs and symbols, general knowledge, model risk assessment, knowing the person(s) involved, the environment (including time pressures), and those posed by unusual circumstances. Assess the risks How likely is it that the procedure could go wrong, how serious would it be if it did go wrong, how many people would be affected? Reduce the risk by adopting control measures It is a requirement to reduce all risks to those as low as possible which still allow the desired end to be achieved. F example, avoid the process altogether and cover it in they only, substitute a safer substance, segregate users from the event, use person protective equipment, other measures identified on the model risk assessment. (See page f further examples of additional hazards and control measures.) Tel: ; Fax: ; science@cleapss.g.uk; Web site:

2 What you need to recd CLEAPSS believes that the significant findings of any risk assessment procedure are best recded on documents in daily use, such as a scheme of wk, lesson plans, wksheets and technician s notes. Recd on your scheme of wk, etc, significant points from the model RA. Don t just recd see Hazcards, but, f example, 0.5M H SO 4, IRRITANT, see Hazcard 98A. Wear eye protection. Warn pupil about cuts from scalpels and count the scalpels out & back in. To demo the radioactives, refer to the Standard Operating Procedures f the use of radioactive sources, and keep sources secure at all times. If you are using a published scheme with safety notes already included, then satisfy yourself that these safety notes are authitative and adequate. If so all you need recd are any significant alterations made in the light of your own circumstances. It is also a good idea to highlight the safety notes in some way to draw attention to them. As we have altered the planned sequence of Y7 / 8 units, this is demo only. Need fume cupboard, swap to chem lab. Allow pupils to take ethanol from small bottle (not large stock bottle) only, and under direct supervision at teacher s bench. If all teachers wk from a common scheme of wk then there may be a need f individual teachers to recd further adjustments in the light of their own personal circumstances. Class 9 JW can undertake this as a class experiment. NQT; must have technician in room to help with this demo. Avoid doing this on Tuesday as pupils are often very excited after drama lesson. If teachers use individual schemes of wk based on an exam syllabus then each should annotate their own SoW with appropriate notes. The HoD should at intervals check that this practice is not being overlooked. The me common the activity and the me experienced the teacher, the less will inevitably be written, a fm of shthand may emerge. This is often OK. However, even f very experienced teachers, safety notes, as described, are essential f unusual particularly hazardous practicals, those undertaken in unusual circumstances, such as a science club open evening. The purposes f recding these safety notes is to ensure that individual teachers have considered the risks associated with their own planned practical wk, and to enable this consideration to be shared among colleagues. Don t fget that if you write your own instruction sheets then these can, and will, include many of the control measures identified by your risk assessment process. Common examples of unsatisfacty practice Notes on SoW are vague, too generalised to be useful, and do not refer to specific hazards sources of infmation, Hazard - refer to CLEAPSS Handbook. Adding all sts of risk assessments into the SoW, from a range of publications including suppliers safety data sheets, resulting in overkill and confusion. This is sometimes a consequence of individuals trying to be though but in fact missing the point of a risk assessment. Safety notes which are way over the top, indicating a lack of real understanding of hazard and risk. Safety notes on teacher s lesson planners that are different from those on the SoW. No department consistency about in which documents safety notes are recded. Page of 5 Tel: ; Fax: ; science@cleapss.g.uk; Web site:

3 What else you need to do Warn others, technicians and pupils. Display written warnings where everybody will read them, technician notes, pupils wksheets, on the whiteboard. Give al warnings so that the intended audience actually hears and understands them, etc. Some examples of less obvious additional hazards which require a model risk assessment to be adapted The following list includes examples that have led to accidents and incidents. Pupils may lack anticipated experience expertise and also some may behave mischievously unpredictably. They may wk me slowly than anticipated and therefe be made to rush towards the end of a lesson. Lab designs where pupils wk with their backs to the teacher. Open evenings, which will involve parents and other adults and children who will not be familiar with lab rules, etc. Primary / secondary liaison visits from Y5 and Y6 children who, in addition to lacking lab experience, are too small to wk comftably at benches to wear standard eye protection. Science clubs which often have a less fmal wking atmosphere than a lesson. Attempting exciting demonstrations in the school hall other unusual venues. Identifying control measures Use me dilute solutions Use less (less waste as well) Reduce the scale of the procedure Use safer alternative substances Use an alternative procedure Use a fume cupboard Use safety screens Perfm a demonstration instead of a class activity Wear eye protection (which should be the most comftable, if possible) Some particular examples: Make sure dangerous chemicals are not stolen. Use mineral wool plugs to slow down the diffusion of a gas vapour out of a test tube. Avoid suckback of water into very hot test tubes using a Bunsen valve. Use leads with shrouded plugs. Hazcards and L95, Safer Chemicals, Safer Reactions suggest examples. Prepare a measured dose so pupils don t take too much. Hazcards and L95, Safer Chemicals, Safer Reactions suggest examples. F example, synthetic crude oil nitration of methyl benzoate. See L95, Safer Chemicals, Safer Reactions. Using beer bottle tops removes the need f expensive pcelain crucibles that are known to crack. Using a plastic food container as a hot water bath is often easier and safer than a beaker heated on a tripod. Hazcards are emphatic about this. A fume cupboard is needed to avoid vapours and gases exceeding the wkplace exposure limit (WEL) in an open labaty. See section of the Labaty Handbook. Beware of scaling up an experiment; it can lead to unftunate circumstances. Safety spectacles are me comftable than goggles. But goggles are necessary f toxic crosive liquids. Magnesium ribbon potassium chlate(v) and, lately, ethanol all have pupil appeal. Use with iron / sulfur heating the cooling curve of stearic acid. It does not always wk though. When using a high-tension power supply (teacher demo only). Page of 5 Tel: ; Fax: ; science@cleapss.g.uk; Web site:

4 Examples of control measurements on a technician s request sheet (see G48) Experiment title / reference Testing a leaf f starch / Activity AB7. Equipment Quantity Comment reference Fresh soft leaves that have been in strong light Kettles Need 4 Fceps 5 0. M iodine solution in dropper bottles 5 CLEAPSS Recipe Card no 9. Test tubes 5 Washing up bowl Eye protection sign Industrial Methylated spirits beaker approx. 00. Beakers 0 See Hazcard 40A. To be used as hot water baths. Teacher notes and control measures f the class Notes to technician including preparation control measures Wear safety specs. Put all test tubes in the washing up bowl at the end. Need to count the fceps in. No Bunsens naked flames on when the meths is being used. Need to put the leaves in a box 4 hours befehand. Teachers: meths is now called industrial denatured alcohol. Experiment title / reference Magnetic field lines using iron filings / Activity 7C. Equipment Quantity Comment reference Bar magnets 0 Ste alternately in full trays with keepers if possible; Section. of the Labaty Handbook. Iron filings in sealed transparent boxes 5 E.g. petri dishes taped shut. Teacher notes and control measures f the class Instruct pupils not to open the transparent boxes, as iron filings are hazardous to the eyes. Notes to technician including preparation control measures Full trays of magnets allow teacher to check me easily that all are returned at the end of the lesson. If magnets need remagnetising, see Section..4 of the Labaty Handbook. Example of control measures as part of a wksheet Investigating the rate of reaction of the acid thiosulfate reaction at various temperatures presents several potential problems. The large volume of thiosulfate solution used, and the waste produced, when the reaction is carried by a class of students using conventional apparatus such as a conical flask. The release of sulfur dioxide gas into the labaty, and the prep room when the technician does the washing up. The use of Bunsen burners, etc, slows down the process so that it takes ages f pupils to obtain readings at 5 different temperatures By a combination of carefully considering and, where appropriate, altering the practical instructions, and giving clear warnings, the risks are easily controlled. The annotated wksheet on the following page illustrates this. Page 4 of 5 Tel: ; Fax: ; science@cleapss.g.uk; Web site:

5 Wear eye protection Transfer of acid to the thiosulfate solution and start the clock. The / Thiosulfate Reaction M sulfuric(vi) acid. Add hot water from the tap to the container. 0 of 0.05 M sodium thiosulfate solution. Once the thiosulfate solution is so cloudy you cannot see the black cross stop the clock. Note the time in seconds. Take the temperature. Replace the thiosulfate vial with an empty clean vial and add another 0 of thiosulfate solution. Enter the results in the table below. Empty the contents of the cloudy thiosulfate vial into the coloured stop bath. Rinse out the vial with water. Eye protection rule f pupils. This method uses about a fifth of other published procedures. These are polypropylene microwave boxes with holes on the top and an inked cross on the base. The hazards are not the reactants but the sulfur dioxide produced in the reaction. By adding the mixture to sodium carbonate, sulfur dioxide and the hydrochlic acid are neutralised and there is little no smell. Care with hot water. 4 Wait minutes befe repeating the procedure in. 5 Try other temperatures but never exceed 60 oc as the time is so sht it is difficult to measure. Using hot water negates the need f Bunsen burners, tripods and stands. 6 Extension F temperatures colder than room temperature, you need to measure the temperature BEFORE and AFTER and take the average. The time to go cloudy takes so long that the temperature of the water bath starts to rise. Temperature Time (seconds) The procedure is so quick that me readings can be obtained than in the me traditional method. Dispose of all liquids down the sink. Safe disposal of residues. F further infmation on risk assessments, see guide L96, Managing Risk Assessment in Science. Page 5 of 5 Tel: ; Fax: ; science@cleapss.g.uk; Web site: