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What Risks Are Tolerable?
- 2. Introductions What Risks Are Tolerable? David McIntyre, Director
- 4. 2. Introduction 2.1 Accidents, God and Science
- 8. Risk Formula Probability of a hazard occurring X Number of People Effected and Seriousness of injuries 4. Definition of Risk 4.2 Risk Formula
- 10. 5. Solve for Risk 5.2 Who and How Badly?
- 11. Qualitative Approach Objective Analysis Hybrid Approach 5. Solve for Risk 5.3 Probability
- 13. 6. What Risks are Tolerable? 6.1 Elimination and Evaluation Eliminate Risks that are not “Real” Evaluate Remaining Risks What about unforeseeable Risks?
- 14. 6. What Risks are Tolerable? 6.2 Unforeseeable Risks
- 16. Because of recent helpful judgements we can take a more sophisticated approach to risk analysis. We should now Eliminate before we Evaluate 6. What Risks are Tolerable? 6.4 Elimination
- 18. 6. What Risks Can be Tolerated? 6.6 Evaluation Evaluation of the Risk
Notes de l'éditeur
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- Judith Green traced the history of ‘the accident’ in her book1 “Risk and Misfortune”. Green defines accidents as misfortunes that satisfy two criteria. Firstly, the event must have been unmotivated (or, at least seen as such). In other words, no person or agency willed the event to take place. Secondly, it must be unpredictable. If it were predictable and were also not intended, the accident would most likely have been prevented or the conditions for its existence would not come about. Today in the west it could reasonably be concluded from listening to the media and by observing the actions of inspectorates that all accidents are predictable and that the concept of accident is redundant. People in the west seem to now believe that “accidents” are the outcomes of complex sets of risk factors. Accidents are no longer considered to be acts of God but instead failures of science. Using this logic the new reality is that all accidents are avoidable and when someone is injured it follows that someone has failed. The “accident” is seen as a failure of systems or individuals to take the necessary steps to prevent misfortune. If only a “suitable and sufficient” risk assessment had been carried out the accident would not have occurred. In our homes, in the air, on road and rail, we now expect modern devices, employers, local authorities and the government to protect us against life's hazards. However, if a risk free world were possible, it would be a reality devoid of innovation and fun, which would make progress impossible. Therefore, the sensible approach is for society to determine what risks it will tolerate? This issue is an “old chestnut” that is often discussed in law for the very good reason that it is a difficult question to answer. One of the problems is that the assessment of risk involves objective and subjective considerations and mixed messages from experts, inspectorates and the courts add to the confusion.
- An accident is the realisation of a risk. The purpose of the Act is to reduce the number of accidents caused by work. Risk is an integral part of the human condition and everyone is exposed to risks on a daily basis. I am concerned with understanding what the law considers to be risks that can be tolerated in the workplace. It is clear that the Act was not intended to eliminate risk completely. This was considered to be impracticable. However, there is insufficient guidance on what risks can be tolerated at any given time. Risks that were tolerated thirty years ago are not now. The reality is of course that there is no clear definition or absolute value for risks that can be tolerated. Employers need to come to their own view based on their own risk assessments and hope that they have done enough. I do not believe that the current situation is satisfactory. To identify risks that can be tolerated, it is firstly necessary to have in place an accurate method of identifying and assessing risks. Only then can risks be sorted and filtered into those that can and those that cannot be tolerated. Therefore, before considering what groups of risk can be tolerated I look at how risk assessments should be carried out.
- R v Board of Trustees of the Science Museum The duty holder, which was in this case the Board of Trustees of the Science Museum had exposed employees and the general public to bacteria which causes legionnaires disease. Despite the fact that no one had become ill, the duty holder was found guilty. “ The starting point must be the ordinary meaning of the language of section 3(1). In our judgment the interpretation of the prosecution fits in best with the language of section 3(1). In the context the word “risks” contains the idea of a possibility of danger.” Adamson v Procurator Fiscal On 8 June 1998 an employee of West of Scotland Water, Mr. Wilson Cowan, was taking water samples adjacent to a field where the appellants kept a bull. Mr. Cowan was gored to death by the bull. “ Section 3(2) of the 1974 Act creates an offence of absolute liability subject only to the defence of reasonable practicability. What requires to be proved by the Crown is that a particular operation exposed persons to the risk of harm, in this case physical injury. It is sufficient for the proof of the existence of risk that a possibility of danger is created. Actual harm need not be proved (R v Board of Trustees of the Science Museum (supra)).”
- There is a formula for calculating risk. This formula is not in the Act or in the Management Regulations, but it can be inferred from descriptions given in the ACOP. Risk = (probability of a hazard occurring) x (number of people effected and seriousness of injuries) This formula can be solved qualitatively or quantitatively. It is usually possible to come to view on the number of people potentially exposed to the risk and the seriousness of the injuries if the hazard eventuated. The probability of a hazard occurring is more difficult to determine. Consequently, a qualitative approach is usually used to assess risks e.g. the risk is high, medium or low.
- As discussed in Chapter 5.3 the Management Regulations ACOP says that “the risk assessment should identify the risks arising from or in connection with work” . It does not say that it is sufficient to identify some risks or the more important risks. A proper assessment of risk can only take place after all elements of the equation are gathered and assessed. The first step is to identify all hazards. Now with any process or activity it is possible to construct a number of complex scenarios that could give rise to a risk. There are a number of techniques as discussed below that could be employed to do this. The Management Regulations ACOP says that “ The level of risk arising from the work activity should determine the degree of sophistication of the risk assessment.” I think this means that at one end of the spectrum there could be the design and operation of a nuclear power station and at the other a typist in an office. With the former it would be necessary to use sophisticated hazard identification tools but not with the later. What is foreseeable is dependent to on the sophistication of the analysis. Consequently, what needs to be achieved is the identification of hazards that can reasonably be foreseen using a type of analysis that is proportionate to the risk. This is consistent with Lord Goff’s view as expressed in the Austin Rover v Inspector of Factories appeal when he referred to “.. reasonable foreseeability...” . I understand that the test of reasonableness should be based on what risks should have been identified using methods with a level of sophistication that was in proportion to the risks being considered. However, I know from my own professional experience that what is reasonably foreseeable or not is a subject for debate in court. After an accident the debate takes place with the benefit of hindsight. What inspectors in the first instance should do is to try very hard to put themselves in the position of the employer before the accident. It is too easy for inspectors and prosecuting authorities to depend on the fact that because there was an accident there must have been a risk that was not adequately dealt with. A systematic approach needs to be used to improve confidence that all hazards have been identified. Each aspect of all processes or work activities needs to be examined. Also, it is clear to me that an employer in isolation cannot identify all hazards. People have a great capacity to short circuit procedures for some perceived marginal benefit. Consequently, employees need to be directly involved in the hazard identification procedure. The Robens Committee saw the advantages to employers and employees working together in this way. Also there is a strong case for external risk assessors to look at processes with a fresh pair of eyes because as discussed in Chapter 3 where emotions may dominate objective analysis. Although there is no absolute scientific objectivity, science could be used to provide greater clarity. There are several well established techniques to identify risks including HAZID50, HAZOP51 PHA52 and FMEA53. In addition, there have been considerable advances in deterministic and probabilistic safety assessment in the nuclear industry. Current well established systematic hazard identification methodologies could be implemented to make risk assessments more robust. During the process of identifying the hazards it is usually possible to determine the potential impacts of the hazards in preparation for calculating risks.
- Risk is a function of probability and there are two methods of assessing probability viz., by subjective and objective analyses. Objective methods can provide good insights into the measurement of risk but of course data may not be available and where it is available it still needs to be treated with caution because it is based on historical data. For example the following problems may exist with the data that could lead to misleading results. 1. Samples that are too small 2. Sample time periods are too short. This may lead to the omission of representative incidents. 3. Historical data is not always a good predictor of the future owing for example to technology changes. Obviously the quality of the modelling and the data will affect the robustness of the numerical estimates of probability. The estimation of numerical values of probability should in practice only be carried out experts in this area. Consequently, a subjective approach is often used by those carrying out risk assessments. However, research has shown that people are not good at assessing probabilities and our assessments can easily be distorted by the way in which we process information, refer to Chapter 3. Therefore, again caution needs to be used when determining probability and risk in this way.
- By definition duty holders cannot be expected to put measures in place to eliminate unforeseeable risks i.e. unknown risks. However, foreseeability is a function of the sophistication of the method of analysis. An appropriate analogy would be the magnification of different sets of binoculars. Farther away objects can be seen using a better quality set of binoculars. Similarly,using a more sophisticated method to identify hazards may identify risks that are not foreseeable using a less sophisticated method. Duty holders are required to use a risk assessment methodology that is suitable in respect of its sophistication for the circumstances. Assuming that an appropriate method is used to identify risks then a duty holder should not be held liable for risks that could not be foreseen using that method. Otherwise foreseeability is a matter of probability. In other words if the probability of the hazard eventuating is very low then it could be said that it is unforeseeable that the event will occur. I think this is what Lord Goff is saying in the Austin Rover v Inspector of Factories case and consolidated in the R v HTM cases, which are discussed below. Therefore it can be inferred that risks that are unknown or unexpected can be tolerated. Austin Rover v Inspector of Factories A paint spray booth and the sump underneath it in the defendants' car assembly plant required regular cleaning, which took place at weekends when the booth was not in use and the ventilation system switched off. The work was contracted out to a firm of specialist industrial cleaners. They were instructed not to use highly inflammable paint thinners from a pipe in the spray booth, which was accordingly turned off by a lever, though not capped, and to enter the sump only with an approved safety lamp and when no other cleaning operations were taking place in the booth above. Contrary to those instructions, an employee of the contractors cleaned the booth by turning on the pipe in the booth and allowing it to overflow into the sump at the same time as another employee was working there with a lamp that was not safety-approved. A sudden flash fire erupted in the sump and the employee there was killed. It was alleged that the defendants had breached their duty under section 4(2) of the Act by failing to ensure that the sump and piped solvent supplies were safe. The justices convicted the defendants after finding that effective isolation of the solvent supply pipe and the provision of mechanical ventilation 'would have been reasonable measures and reasonably practicable for a person like' the defendants, who had accordingly failed to take reasonable measures to ensure that the pipe and the sump were safe. The Divisional Court of the Queen's Bench Division quashed the conviction. The inspector of factories appealed to the House of Lords the appeal was rejected. It was found that it was not reasonable to require measures to be taken against unknown and unexpected events, and, since the justices had not made any findings as to whether the unanticipated use by the contractors‘ employees should have been foreseen by the defendants, it could not have been said that it would have been reasonable for them to take measures to make the premises safe against that misuse. With respect to foreseeability Lord Goff said the following. “ It is at this stage that reasonable foreseeability becomes relevant, in the sense that there has to be an assessment of the likelihood of the incidence of risk.” I believe the reasonableness or otherwise of what can be foreseen turns on whether the methodology to identify hazards and consequently risks was appropriate for the circumstances. R v H. T. M. Ltd The defendants were providing traffic management services. The traffic was subject to contraflow arrangements which were lit at each end by mobile telescopic towers provided by the defendants which extended to a height of 9.1 meters. Overhead power cables crossed the road carrying 20,000 volts of electricity and were as low as 7.5 meters above ground level in places. Two of the defendant’s employees were engaged in moving one of the towers. They did not lower the tower as a result it came into contact with the power cables and both employees were fatally injured. Concerning the matter of forseeability the appeal court was asked to determine the extent to which the defendant’s evidence about forseeability was irrelevant to the case, particularly with regard to the reasonable practicability of ensuring the health, safety and welfare of their employees. “ In our view, Lord Goff's analysis of what is the right approach, is the one which, on the authorities, correctly identifies the proper approach to the jury question posed by the relevant phrase. It is to be noted that he expresses the relevance of forseeability in a closely confined way. Forseeability is merely a tool with which to assess the likelihood of a risk eventuating.”
- Hypothetical Risks This category of risk is characterised by the following words. Hypothetical Trivial Fanciful Another word that is used to distinguish between hypothetical risks and risks that need to be eliminated are “real” or “material”. It seems that “real risks” need to be eliminated but hypothetical risks can be tolerated. In the R v Chargot case discussed below, the test for a real risk is one that the “reasonable person would appreciate”. This has profound consequences because the benchmark is the “reasonable person” not the “reasonably competent expert”. This seems inconsistent with other requirements. R v Chargot A dumper truck driver was told to take a load of spoil to a hole into which it was to be deposited. As he was driving down a ramp, the dumper truck fell onto its side and he was buried under the spoil and died. Lord Hope included the following statements in his speech. “ The question then is whether this approach to the legislation is proportionate. The first point to be made is that when the legislation refers to risks it is not contemplating risks that are trivial or fanciful. It is not its purpose to impose burdens on employers that are wholly unreasonable.” “ The law does not aim to create an environment that is entirely risk free. It concerns itself with risks that are material. That, in effect, is what the word “risk” which the statute uses means. It is directed at situations where there is a material risk to health and safety, which any reasonable person would appreciate and take steps to guard against.” Lord Hope confirms that there are risks that can be tolerated. Risks that can be tolerated are material risks that a reasonable person would appreciate. I have a problem with the “reasonable person” test. It was shown in Chapter 3 that there are issues about relying on the reasonable person’s assessment of risk. Therefore, it would be better that the test is carried out by a reasonably competent expert. In particular the expert should be able to arrive at a better estimate of probability. It seems that the courts do not appreciate that risk assessment is a science and consequently are prepared, wrongly in my view, to accept subjective assessments of risk carried out by the reasonable person. R v Porter The case concerned the death of a three-year old boy who had suffered a head injury when he jumped off the fourth step from the bottom of a flight of steps in the playground at his school. Some four years after the incident, Mr Porter, was tried and convicted for breach of Section 3 of the Act, the charge was that he caused a risk of falling from the flight of steps, to which children aged three to four years could gain unsupervised access. In the first instance the judge took the view that the jury could properly conclude that the steps constituted a risk to the safety of a child if they were to descend unsupervised, and it would be reasonably practicable to prevent the child from descending the steps by providing constant supervision (although there was no allegation that there should be constant supervision). Mr Porter was convicted and he took the case to the Court of Appeal. The Court of Appeal concluded that the risk, which the prosecution had to prove, was a real risk as opposed to merely fanciful or hypothetical. “ There is no obligation under the statute to alleviate those risks which are merely fanciful.” The Court then considered how a real risk should be distinguished. The Court said that in most, if not every case, there would be important factors to be taken into account, none of which would be determinative but many of which would be important. The relevant factors in this case included: 1. the absence of any previous accident in circumstances which occurred day after day; 2. the unchanged levels of supervision in the playground; 3. the fact that there was nothing wrong with the construction of the steps. The Court had no criticism of the risk assessment carried out by the defendant, which had addressed supervision in the playground but had not identified any risk in relation to different levels on the playground or the flight of steps. The Court of Appeal found that the fact a young child might slip or trip, or jump from one height to a lower level, was part everyday life. This was considered to be highly relevant. ‘ Where the risk can truly be said to be part of the incidence of everyday life, it is less likely that the injured person could be said to have been exposed to risk by the conduct of the operations in question’. All the evidence suggested that the only risk was that, every time a child was left other than closely supervised, he might venture unsupervised down a flight of steps. The Court of Appeal took the view that this did not constitute exposure to risk sufficiently to establish liability under Section 3 of the Act. Therefore the issue of whether Mr Porter had done everything reasonably practicable to avoid the risk did not arise. The appeal court repeated the view given in R v Chargot that it was not necessary for duty holders to alleviate hypothetical risks. However, instead of the reasonable person test it gave important indicia. In essence the court concluded that the “trivial risks of everyday life” should be tolerated unless there was something odd or different that altered the usual probability and impact of an accident or the incidence of previous accidents would lead one to believe that there was something unusual.
- Edwards v National Coal Board A colliery employee, while walking along a road in a South Wales coal mine, in the course of his duties, was killed by the fall of a considerable portion of the side of the road. The plaintiff claimed damages from the National Coal Board. The defendants contended that it was "not reasonably practicable to avoid a breach" and therefore they should be excused from liability. Lord Asquith included the following statement in his speech. "Reasonably practicable" is a narrower term than "physically possible" and seems to me to imply that a computation must be made by the owner, in which the quantum of risk is placed on one scale and the sacrifice involved in the measures necessary for averting the risk (whether in money, time or trouble) is placed in the other; and that if it be shown that there is a gross disproportion between them - the risk being insignificant in relation to the sacrifice - the defendants discharge the onus on them.” The first matter to note is that just because it is possible to do something to eliminate a risk it is not necessarily the case that it needs to be done. The test is how the “sacrifice” relates to the risk. The relationship is governed by the term “gross disproportion”. Therefore, it is not sufficient to demonstrate the scales are tipped moderately on the side of sacrifice. In essence it needs to be clear that it simply does not make sense to sacrifice so much to eliminate the risk. The guidance is of course useful to an extent but it remains vague and therefore there are difficulties applying this test in practice. However, it can usefully be used to identify risks that may be tolerated. The guidance could be improved by the application of a more scientific approach to provide greater definition. Ultimately, everything reduces down to cost. Therefore, if cost becomes the unit of comparison then is the test of “ gross disproportion” satisfied when risk is one unit and sacrifice is ten units? Owing to society’s general distaste about putting values on human lives then “gross disproportion” is likely to be satisfied by a ratio of at least a thousand to one. However, expressing the situation in these terms would be helpful. In practice the courts and the inspectorates have avoided the issue and left it to duty holders to come to their own view on this matter. It is obviously possible to provide clearer advice and this would be welcomed by dutyholders.
- Notwithstanding the difficulties discussed above concerning the identification and evaluation or risk, let us assume for the purposes of this discussion that all risks have been identified and measured. We now ought to be able to sort and filter out those risks that can be tolerated from the rest. There is no objective analysis to rely on and consequently it is not possible to say that risks with a value below some threshold number can be tolerated. Nevertheless decisions by the courts allow the removal of certain categories of risk and it is possible to filter the remainder based on practicability. Sorting – the following categories or risk can be tolerated and therefore disregarded in respect of further analysis. Insignificant Unexpected Unlikely Hypothetical Theoretical Fanciful Every day risks Based on the R v Porter case the prosecution must prove that the risk is a real risk as opposed to merely fanciful or hypothetical and has given some guidance on how to determine whether a risk is hypothetical. The principal one being that where an activity has been carried out on a daily basis for a considerable period of time then absence of any previous accident is a good indicator that it is a hypothetical risk. This indicator is not determinative and in my view this is correct. I investigated an accident that resulted from carrying out an activity that had been used on a daily basis for many years. However, despite the fact it was accepted by the employer, employees and was apparently used by others in the industry, the procedure was inherently flawed. It was my view that the risk was not hypothetical and should have been eliminated. The activity was changed to one that was not only safe but substantially quicker. The risk was eliminated but only after someone had died. The activity had become part of the scenery and had consciously or unconsciously filtered out by those carrying out the risk assessments because they had failed to carry it out in a detailed and systematic fashion. Therefore, although it is unsatisfactory it is impossible to currently provide hard and fast rules. Filtering – where there is a gross disproportion between risk and the measures for averting the risk then nothing needs to be done about the risk. Lord Asquith included the following statement in his speech concerning Edwards v National Coal Board. This speech was made in 1949 before the Act came into being but is still relied upon. "Reasonably practicable" is a narrower term than "physically possible" and seems to me to imply that a computation must be made by the owner, in which the quantum of risk is placed on one scale and the sacrifice involved in the measures necessary for averting the risk (whether in money, time or trouble) is placed in the other; and that if it be shown that there is a gross disproportion between them - the risk being insignificant in relation to the sacrifice - the defendants discharge the onus on them.”
- Some categories of risk can be tolerated and others can be tolerated because it would be too much trouble to do anything about them.The categories of risk that can be tolerated are: Insignificant, unexpected, unlikely, hypothetical, theoretical, fanciful and every day risks. Critically the R v Porter case tells us that if an activity has occurred on thousands of previous occasions without incident then it is likely to be a hypothetical risk. Removal of tolerable risks should only be made on the basis of a robust risk assessment. There are no absolute values for the level of risk that can be tolerated. However, the following stepwise process needs to be followed to determine what risks can be tolerated for each set of circumstances. Select a method of identifying hazards with a sophistication that is proportional to the circumstances. The risks that can be foreseen are a function of the sophistication of the detection methodology. Therefore, only risks that can be reasonably foreseen need to be considered others are tolerated by default. Systematically identify all hazards Determine all the parameters of the health and safety risk equation for each hazard. Careful consideration needs to be given to the assessment of probability of the hazard eventuating. Calculate the risk for all hazards. Judge what risks can be tolerated using the following guidance. o Identify fanciful, theoretical or hypothetical risks o Identify risks associated with normal day to day life o Filter out risks that are grossly out of proportion with the money, time or trouble that it would take to eliminate or mitigate can be ignored. People are not good at assessing probability and consequently risk The HSE suggests that carrying out a risk assessment does not need to be complicated. I reject this suggestion, unless risk assessment are completed carefully and thoroughly then employers will not identify all risks that cannot be tolerated and consequently run the risk of an accident occurring and prosecution for breach of the Act. More robust risk assessments should be carried out but this will inevitably require skilled practitioners. A national certificate should be introduced for risk assessment and only risk assessments carried out by qualified assessors should be valid. The HSE ought to face up to the fact that the methodologies used to carry out risk assessments have limitations and this often results to deficiencies in the assessments. Employers that carry out systematic and thoughtful risk assessments should not be exposed to the risk of prosecution. Owing to the complexities of assessing risks and the way people assess risks there is perhaps a need to have special prosecutors, courts and/or judges to consider health and safety matters in a similar way to the Technology and Construction Court. Greater rigour in the assessment or risks and increasing specialisation should lead to a situation where tolerable risks can be identified with greater certainty.