Posted By Stephen Lambert Specifically with respect to fire escapes, much will depend if it is the only escape. Other factors will be capabilities of staff (speed of movement), reaction to alarm in terms of discipline and management of the escape strategy. So if the escape in question can be 'managed out' of the strategy, the effects of its non-availability will be lower than if it is essential to safe escape. This suggests that, if you rationalise your escape strategy so that each group in the workplace has a minimum of 2 escape routes (preferably diametrically opposed but separated by an angle of no less than 45 degrees) so that, from any point, a person can turn their back on a fire and escape to safety and arranged so a fire that blocks one route will not make the other unusable, the non-availability of a third escape route would not be a significant contributor to the hazard. However, if the escape is one of the 2 identified routes, a significant hazard requiring action emerges and if the blocked escape can affect the 2 identified routes (or is the only route available), an automatically unacceptable hazard emerges.

Posted By Ken Taylor The approach to take is on the basis that legal duties must be met (eg keeping means of escape unobstructed), defects should be remedied and that risk assessment is a means of controlling the residual significant risks that are part of the working situation.

Posted By Laurie I agree with Nick. Thses matrices are ideal for an inexperienced assessor to quantify the risk, and as a basis for justifying an assessment to lay persons, but in 90% of scenarios a health and safety professional, working in his own area of familiarity, should be able to assess the risk simply by experience and knowledge. Laurie

Posted By Adrian Watson Dear All, I would like to add a some points. Semi-qualitative risk ranking is more an art than a science and the Risk Matrix is but a tool in the safety practitioner toolkit. To me their main benefit of the Risk Matrix is that it makes the risk ranking obvious and as such challengeable by all interested parties. However, the main problem with their use is that people get too hooked on the precision of the results. As the computer acronym GOGO reminds us "garbage in - garbage out." I note that somebody has suggested that you should use a 7 x 7 matrix. My question is why? What benefits does a large matrix have other than contribute to the confusion. In my experience the best size for a risk matrix is a 4 x 4, because it is large enough to rank most risks but small enough not to waste time on and it forces a decision as it has no middle choice. If you have to get a precise, "repeatable" result get a number of people to plot the ranks independently. Then get them to state how and why they came to the conclusion that they did. It opens the world on anothers point of view and as such the results are valuable just for that. In addition to the above I have a problem with the normal risk assessment process in that risk is defined as "Risk = Probability x Severity." This suggests that a fatality that is probable or likely before something that is serious and highly likely, i.e. you are dealing with two things equally, when they are not equal, because one is more likely than the other. In reality whilst risk is a function of severity and probability it is also a function of acceptability and cost. I would like to add it is oft forgot, that the aim of a risk matrix and risk assessment is to prioritise actions to ensure that scarce resources are allocated where they needed most to prevent ill health and injury. So as all good practitioners I shall finally answer the original question "In defining risk levels i.e. High, Medium, Low for the purpose of inspection of work place hazards. How does the 3x3 Matrix risk = severity x likelihood fit into something like say a blocked fire escape? " The answer is it doesn't! If there is a risk of fire, then there is a requirement for an escape route to a safe means of escape. The risk of fire fits in the matrix, but the controls don't. Therefore all the time that there is a risk of fire, then there exists the need for a clear escape route to a safe means of exit. As an aside I would add that if you cannot maintain such conditions then you have a failure of management and have greater issues to look at. Many Regards Adrian Watson

Posted By Adrian Watson Dear Ken, Please read the last paragraph, again. I agree totally, a risk assessment is not appropriate. Action is! Regards Adrian Watson

Posted By Gavin A lot of work has been carried out comparing the scoring options for market research and school exams - despite the broad range of options, ie A+, A, A-,B+. etc, only a limited range are actually used. Do not make the mistake of assuming that more complex is better - keep it short and simple (KISS). All that your scoring has to do is to prioritise your actions, typically immediate, within 3 days or within 1 week. What else would you do - have the task rated for completion within 1 hour, 3 hours, 6 hours, 12 hours... As long as you are consistent with your definitions of how you rate things it does not matter. Ensure your system is clear and transparent. The other option is to use the same rating as you use for your risk assessment.