THE ALARP DEMONSTRATION IN THE OFFSHORE ENVIRONMENT

The HSE say the following in their 2009 “Demonstration of ALARP” document which is actually written for the nuclear industry:

The requirement for risks to be ALARP is fundamental and applies to all activities within the scope of the Health and Safety at Work Act. It is important that inspectors, in whatever role, are aware of the need to ensure that licensees meet this requirement. In simple terms it is a requirement to take all measures to reduce risk which are not unreasonably costly. In many cases this is not done explicitly, but rather by the establishment and/or use of relevant good practices and standards. The development of good practices and standards includes ALARP considerations so in many cases meeting them is sufficient. In other cases, either where standards and relevant good practices are less evident or not fully applicable, the onus is on the licensee to implement measures to the point where the costs of any further measures would be grossly disproportionate to the risks they would reduce.

To elaborate on this statement, the UK regulators are really saying that if you are following established rules, guidance and best practice you can consider your risk in carrying out whatever task is being reviewed as ALARP, but first of all you have to decide what hazards are to be assessed.

I know about mobile drilling units, so to use them as an example, the industry has over the last 20 years pretty well determined what semi-submersibles, jack-ups and drill ships do and hence to what hazards they are exposed. So it is good enough to get hold of the existing list of hazards and to assess the risks relating to them (in safety speak the realization of the hazards)using what-ever means seem to be suitable. The drilling industry as a whole is very averse to QRA (Quantitative Risk Analysis) which is the determination of the seriousness of the risk by accessing existing records, and doing some calculations, but it can be helpful particularly to determine whether risks are ALARP. Hence if an event is only likely to occur once in a million years according to your QRA, you don’t have to make a big effort to reduce the risks further. But if the event is likely to occur every 100 years the requirements will be completely different, and you will have much to do.

One of the failings of QRA is that it does not usually result in recommendations, it just tells you how things are, and another is that it can easily be manipulated to produce the required results. Safety records vary depending on which part of the world one is considering so levels of risk are easily over or under stated. So in order to ensure that risk are ALARP some sort of qualitative work is required. There are a number of techniques, but one of the most effective is probably the bowtie method. This is not an article intended to promote any particular software, but BowtieXP works very well.

Hence in order to ensure that risks are ALARP regular risk assessments should be undertaken and the recommendations resulting from them carried out. What if there are no recommendations I hear you ask, and what is meant by regular? The answer it that there should always be recommendations resulting from an assessment of major hazards, and that “regular” may be only as often as every five years.

The UK health and safety ethos is that there is always room for improvement, but that eventually the cost of making the improvements will be pointless, since the reduction in risk will be minimal. To use an example, when considering the risk of capsize of a semi-submersible due to loss of stability (which has happened less often than one might think) it may not be worthwhile making major structural changes to a rig, but it will always be worth training the ballast control operators how to do the job. This is considering what is known as “gross disproportion”.

So in order to ensure that one’s risks are ALARP, one has to carry out risk assessments regularly and then carry out the resulting recommendations as long as they will actually result in a reduction in risk. It is an iterative process.

Victor Gibson. September 2012