Posted By notsothicko I have been challenged as to whether we need to risk rate our hazards using a numerical matrix (ie usual 5 X 5)to give a numerical risk rating when carrying out risk assesments - why not just a high / med / low ? Is this type of rating standard / normal practice in the big wide world - its how I was always taught but would like to see what other people do.

Posted By Merv Newman Notso, I think most (some ?) people draw up their grids with phrases such as Fatal, Severe, moderate, light to describe the probable severity and Continual, Frequent, Infrequent or even daily, weekly, yearly to describe the frequency of exposure. INSIDE your grid you can show that a "continual exposure to a fatal injury" is rated as "priority 1" and "occasional exposure to a light or minor injury" is rated as "priority 5" Oh, and anything that comes out as a 1 or a 2 is usually treated as STOP DOING THAT. NOW ! It's the way we do it. Merv

Posted By Natasha Davies Hi There I agree with the earlier posting relating to the importance of being able to prioritise actions regardless of format used, however using a numerical format to come to your High, Med, Low conclusion enables you to demonstrate you have considered your liklihood and severity when assessing risks associated with identified hazards. Regards

Posted By J Ridley No need to quantify any risk assessment as long as what is being assessed is carefully looked at, those at risk identified and it specifies the hazard and level of risk at each stage with periodic review. All this can either be quantitive i.e scoresheet or qualitative i.e. competent assessors opinion. Indeed, I see a lot of assessors concentrating too much at filling in the form rather than concentrating on the task, who can be harmed and how, and whether the current controls measures are suitable and sufficient or not. You may hear various opinions on this, but there is no legal requirement to quantify any assessment, although many people, perhaps those with real influence within 'organisations' may still prefer. I hope this helps buddy.

Posted By Lawrence Waterman You should bear in mind that one of the outcomes of the new CDM Regulations, for construction work, is that the HSE has taken the opportunity to argue strongly against numerical matrices for design risk assessments. There is a problem with numerical systems - they appear to provide a good method of comparing risks but in reality the numbers are only acceptable if they accord with the judgements you'd make without them. You never want to be in a position of arguing that one risk was more significant than another solely on the basis of the score. They also beg questions - do you score before applying controls (pointless) or when controls are in place to evaluate the residual risk? How do you allow for risks for which there are readily available, simple, inexpensive controls but which score too low to be on an early action list (yet quick wins can help win people to take sensible action)? 5x5 matrices are probably used more for presentation, to show that stuff has been addressed, than making a real contribution to risk management.

Posted By PETER GANNAWAY A lot of organisations swear by numerical systems whereas others swear at them. A truly quantitative system such as those examining failure rates in safety systems based on published research are valid. A semi-quantitative system as a numerical system is seems to confirm more science on a situation than they deserve. They are based on individual's opinion, dressed up as fact. I prefer an honest qualitative approach which is based on an individuals reasoned explanation.

Posted By Dr Graham Marshall IFAP in Australia (www.ifap.asn.au) have produced an online Risk NomoGram which addressed risk assessment against: Consequence X Probability X Exposure. I find it a very easy tool to use which gives both a risk score (ie. a number from 1-500) and a risk rating (ie, Severe, High, Medium to High, Medium, Low). Also, The Hazard Management Book (www.thehazardmanagementbook.com) provides a good JHA format which includes an Event Potential Matrix for easy risk assessment. regards, Graham

Posted By Mark Darmody From my experience I have found using matrix systems counter productive. Individuals perceptions of risk differ. Laura was spot on at the start of the thread prioritising actions is the key . Mark

Posted By Peter Leese From my experience I have found using matrix systems excellent. Individuals perception of risk differ and the use of a matrix (and the same trainer) helps attain standardisation across an organisation.

Posted By Dr Graham Marshall Hello again, while I agree with some of what Adrian says, I must admit that his good intention is also steered off track by an inadequate understanding of hazards. This bit of what Adrian says is definately true "Much of the present problem is due to a misunderstanding of the concept of hazards and risks. I think we should go back to the starting board and consider what we mean by Hazard and Risk". This bit is also true - "I know that I have said this before, but I will say it again. Hazard is not, repeat not, something with the potential to cause harm". However, this definition is not true - "Hazard is an event with the potential to cause harm". Hazards are not 'something' with the potential to cause harm. Nor are they 'event's. Hazards are sources of energy with the potential to cause harm. What we need to look for in identifying hazards is the energy involved which is hazardous. Using Adrians good example - A stepladder is not hazardous; using the wrong stepladder or using a stepladder wrongly is hazardous - because it involves a source of energy (the potential to move - physical (kinetic) energy). The stepladder is harmless! The physical energy associated with using a ladder is what has the potential to go out of control and cause some kind of unwanted event (and its associated consequences). So for example, if the ladder topples; or you fall from a ladder; or you drop a tool from a ladder - physical energy goes out of control and some kind of harm may occur from the topple, fall or dropping object. The hazard is the energy involved. Other hazardous sources of energy include chemicals, radiation, electricity, environmental sources (e.g., lightning, earthquakes, bush fires), ergonomic (energy inside our muscles), psychological hazards (energy in our heads - motivations, drives), biological hazards (harmful things that are 'energised' by life - bacteria, viruses, bears,snakes, etc). Based on the above, once we have identified the hazards, we can 'assess the risk', by evaluating the hazard potential. This is basically a consideration of the potential for a hazard to go out of control (the likelihood)and the possible consequences of such a loss of control of the hazard. So for example, if we were flying a kite on top of a hill during a lightning storm, the hazard would be the environmental hazard (in the form of naturally occuring electricity), and the hazard potential (risk) would be fairly high - based on the strong liklihood that we could be struck by lightning and the potential consequence (death or serious injury) from such an electric shock. This is my understanding of the hazard-risk relationship. regards, Dr Graham Marshall

Posted By Dr Graham Marshall Adrian, I don't think we're a million miles away on this issue. The thing I've noticed over the years is that people aren't very good at identifying hazards because so many things have been called 'hazards'. The approach I've taken in trying to get across to people the Hazards and Risk Management (HARM) Process follows: Step 1. Identify the hazards within an activity (defined as types of energy with the potential to harm) and the 'threats' (defined as things that can cause the unwanted release of a hazardous energy source). Step 2. Identify the hazard potential (in terms of the types of events that can occur when hazardous energy goes out of control (eg, chemical spill, electric shock, slip, trip fall, exposure to something) and the consequences of these events (eg, environment harm, death, injury, equipment damage, delay, etc). Step 3. Decide if you want to control the hazards (this is the risk assessment question - yes or no) and then identify and implement the right controls (both preventative and recovery/mitigative)and considering the control hierarchy. In the above process your "psychological stress", and "oxygen-deficient" atmospheres become 'threats'. An oxygen deficient atmosphere will simply be replaced (in most terrestrial circumstance) by a hazardous chemical (eg, CO2). In space, there is a vacuum which is hazardous where the model falls over, but I can live with this since most people are not Cosmonauts. Non-reactive substances may be a hazardous chemical - I'm not sure. I use the term "Event" to mean the set of conditions that combine to produce the event. A hazardous event involves physical, chemical, biological or psycho-social stressors acting at a time and space upon an individual or group of individuals. I'd suggest that the 'event' involves the release of a hazard (energy source) by the sum set of threats which may relate to 'people' (e.g., drunk, drugged, fatigued,untrained, etc), 'process' (eg, rushing, no JHA, concurrent activitities, etc), 'equipment' (eg, wrong tool, poorly serviced, unguarded,etc) or 'environment' (eg, dark, slippery surface, hot/cold, unventillated, etc). In respect of the ladder the fall height, the rate of energy transfer on impact and the susceptibility of the individual will also affect the hazard potential. Therefore, energy is a factor but not the only factor. Once again, physical energy is the hazard we need to manage. Wrong choice of ladder, wrong angle of ladder, not footed, not tied off, untrained person, fear of heights, darkness, rushing, risk taking attitudes - all are 'threats' that combine to release the hazardopus energy resulting in topple, falling person or dropping tool. the hazard remains the physical energy (kinetic hazard). A toxic material in a toxic material in a flask may be toxic, but it is not hazardous. A toxic material is a chemical hazard (at all times with the potential to cause harm). The flask leaking (equipment threat = wrong container, ill fitting lid, wrong storage location, heat, cold, etc) or breaking may release the material. In which case the hazard (chemical) event is a release of toxic material from a broken flask. The event is thus a spill of hazardous chemical. So for your example of flying a kite on top of a hill (process threat) during a lightning storm (environmental threat). The hazardous event of being hit by electricity (electrical hazard) is high because the activity of flying a kite acts as a preferential pathway for the electricity. The hazardous agent is a large amount of energy in the form of naturally occurring high-voltage electricity. The wet string (equipment threat) and environmental conditions (environmental threats) acts as a preferential pathway for the electricity to earth. The individual's activity "flying the kite", will increase the probability of being hit, whilst wearing wet clothing (person threat) and the person's health status (person threat) will determine the effect of the strike upon the body. Variability in any of the factors will affect the degree of hazard. Agreed. Cheers, G

Posted By Pete48 Yet another thread that discusses risk rating without specifying a context. For me risk is about How often? How big? and So what? Take driving your car, try using your simple risk matrix and derive a risk rating for that every day risk. Are you going to list out the hazards without any controls in place or recognise them and note them down then "rate" your risk? How would you decide on whether to replace a car that does not have ABS for example or fit new tyres as the existing ones are 3mm depth? If it works then using it on your workplace may suffice. If it doesn't because either it gives you an answer you didn't expect, one that is senseless or it seems a waste of time ask yourself-why? Do you know the rules about combining frequencies and probabilities and which means what? Do you understand fault tree and event tree analysis. If you do then you can make good use of mathematical matrices even simple ones, if not then you will usually fail and produce a qualitative judgement given some "weight" by the apparent science. I share Adrian's concerns about the use of a simple matrix and the strange results it can give. As he goes on to suggest, it is both the total number and type of events that have to happen in order for a single harmful event to occur that gives a closer definition of risk. Thus whether flying kites, using a stepladder or storing chemicals, all need a number of situations and /or failures to occur in order to provide the described outcome. So without thinking too much about it, I am personally more likely to be harmed using a stepladder than flying a kite, does that make it higher risk? or just more urgent that I make sure I have all the risk controls in place for using a stepladder? At this level of assessment, I am a believer in qualitative assessment. Thankfully I think that the HSE see it this way as well. QRA has its place but needs skilled practitioners to use it effectively.

Posted By Rob Randall Hi, The system that I have developed, although not genuinely quantitative, is a bit more than just a qualitative system dressed up as science. I look at an activity, and the environment in which the activity is taking place, and list all of the controls necessary for the activity to be conducted with the minimum acceptable risk. Each of the "necessary controls" is then given a value in accordance with their importance in reducing the risk. The controls that are missing from the actual situation therefore become the recommended additional controls. Each of these "necessary actions" is then allocated a priority in accordance with its importance. The total "necessary control" values give an overall risk rating, (i.e. the risk that would exist if no controls were in place) and the "necessary actions" values are then divided by the existing control values and the result is multiplied by 100 to give a "percentage risk rating". The necessary actions are prioritised as "immediate", "high" "medium" or "low" with a specific definition given to each priority in terms of a timescale for implementation, the potential severity of an injury if the control is not implemented and the likelihood of attracting enforcement action or civil action. There is an additional subjective adjustment used in some cases to either increase or decrease the residual risk rating to take account of factors such is actual exposure to the risk as opposed to theoretical exposure and the relative effectiveness of the management regime. I have found that this gives clients a quantitative measurement that they can aim at improving without compromising my need to give a professional judgement. Incidentally a stepladder, if it is in a poor state of repair or otherwise unsuitable for use, is a hazard if it is in a situation where it is likely to be used. Remove the stepladder and you have eliminated the hazard. The over technical explanations of the term hazard and risk are unhelpful. A hole in the ground is a hazard and is so independently of any event. It is the likelihood of the event taking place, i.e. a person falling into the hole plus the severity of the resulting injury that constitutes residual risk.

Posted By Adrian Watson Tony, Risk assessment can be an art and science. However, what is really important is the attitude that the person stops and thinks "what do I have to do to avoid injuring myself and others" before carrying out the work and then takes action. The process I use is easier to demonstrate than talk about; it takes me around 5 minutes to demonstrate it to a worker in a workplace. It takes a "bit" longer for a "safety practitioner" because they have preconceived ideas. I have no doubts the approach works better than existing systems, but I would like to test it experimentally. Whilst I do not use risk matrices in the workplace, unless the client requires it, I do use risk assessments to identify appropriate controls. I disagree that the key to effective risk assessment is experience and consistency. It is a simple, consistent and methodical approach. I for one, do not care a jot whether Joe rates X as being a greater risk than John; However, I do care greatly that they both take appropriate measures to eliminate unnecessary risks. I whole hearty agree with the sentiments that nothing replaces the ability of the observer to look at the scaffold and think "That don't look right" or for that matter the individual flying a kite in a thunderstorm. That ability, with the "I must sort it out" attitude are what we need. Regards Adrian