Continuous monitoring of hand arm vibration exposures (and why employers shouldn’t rely on it)

With over 30 years as a highly respected HSE research scientist, and now with Finch Consulting as a specialist in the noise and vibration team investigating claims as an expert witness and advising clients in reducing risk and good practice, Sue Hewitt is one of the best placed experts in the UK to advise on HAVS and NIHL. Known widely for her pragmatism, in this article Sue offers advice to employers on continuous monitoring of hand arm vibration exposures.

When considering the evidence produced by a defendant in a personal injury claim for Hand Arm Vibration Syndrome, it is quite common to receive a huge pile of daily vibration exposure timesheets completed either by, or on behalf of the claimant. Alternatively, sometimes the evidence contains computer files and printouts generated by a personal vibration exposure monitoring system. My heart sinks when I see all this evidence waiting to be considered. This is not only because it can be a very tedious process, trying to work out which elements, if any, have relevance to the case, but also because of the amount of wasted resource, both in terms of time and of money, that in my experience it invariably represents. In situations where resources are finite (most situations, I would assume) the excess administrative burden of a paper system, or the costs of hiring or purchasing an electronic system could be avoided, and those valuable resources could be directed towards the important process of reducing risk and controlling vibration exposure instead.

When considering the information provided, more often than not there are concerns over the validity of the data for one reason or another. For example, claimants may say that they did not complete the forms themselves, or that they would be obliged to complete multiple copies in one sitting to bring records up to date, or that they did not understand the forms and just completed them as instructed by the supervisor. When files or printouts from monitoring systems are produced, they tend to be incomplete in terms of chronology with no explanation as to why this is, casting doubt as to whether only certain selected parts of the evidence have been presented. In other cases, the vibration magnitude data on which calculations are based are surprisingly low, or appear to change without explanation, making it unclear if the change represents a real change in tooling, new information on the existing tooling, or even an error in programming. Frequently, daily exposures of a few seconds are reported, raising concerns over whether the monitoring device was functioning correctly. Added to this, the claimant may report that the device did not work properly, that batteries frequently ran out, or even that the device frequently fell off the tool. I have been told of one instance where an employee using an electronic monitoring device, and struggling to start the somewhat temperamental two stroke engine of a hedge trimmer, recorded reaching the Exposure Action Value before he had even managed to get the engine running, let alone cut any hedges. To date, I have not analysed a single case where exposure monitoring information contained any convincing evidence regarding the claimant’s daily vibration exposure.

It is also a common misconception that continuous monitoring of vibration exposure is required by the Control of Vibration at Work Regulations. It is not. HSE has published guidance on its website which includes advice to the contrary.

Monitoring daily vibration exposure is not a substitute for controlling exposures to as low as reasonably practicable. If employees have significant vibration exposures (for example, if the daily vibration exposure is likely to reach or exceed the Exposure Action Value) then any system of setting a limit, combined with retrospective recording of exposures is likely to result in employees, on at least some occasions, exceeding the set limit before they have worked out that they have done so. Conversely, if employees do not have significant exposures, then this can be demonstrated by a risk assessment and there is no added value in continuously recording exposures thereafter.

It is also probably unrealistic and unreasonable to expect an employee who has been given a job to do, to stop work because their vibration exposure has reached its maximum permitted level. It is likely that the need to meet deadlines or complete tasks will prevent this from happening. I have been told of circumstances where an employer made the decision to ban daily vibration exposures in excess of the Exposure Action Value and made it a disciplinary offence not to comply. However, the employer had not put in place any alternative methods of working to make it possible for the job to be completed by other means, leaving the employee in an impossible position. A similar situation can arise when an employee has been given a positive diagnosis of HAVS at an early stage and is advised by the occupational health provider that they can continue working, but should reduce their exposure. In these circumstances again, it is not enough to simply reduce that individual’s personal limit, without taking positive action to manage the workload. It is important to make sure that there are actual changes to what the individual is required to do, otherwise they are still likely at times to exceed whatever new limit has been set.

What the Vibration Regulations do require is that the vibration risk should be reduced to as low as reasonably practicable. The employer needs to be able to demonstrate that they have done this, and exposure data alone is not sufficient for this purpose. This can only be achieved by understanding and planning the work allocation to make sure that vibration exposures are also understood and are controlled. To achieve this, it may be necessary to carry out a period of monitoring of exposure times, to ensure that tool usage is understood and recorded for typical tasks or work patterns. After this process has been completed, provided that there is evidence that employees’ exposures will not reach the Exposure Limit Value, and provided that a suitable system of work allocation is adopted, there should be no need for daily monitoring of vibration exposure to continue. Having said this, periodic random sampling of exposuresmay help to verify that exposures are controlled, and also periodic auditing of the work allocation process could help to make sure it is being properly applied.

This article is one of a series offering pragmatic and practical advice on managing hand arm vibration and controlling vibration exposure. The whole series will be published over the next few weeks on our website. The next planned article will discuss the merits, or otherwise, of antivibration gloves.

If you would like to discuss any of the issues raised in these articles, please contact [email protected]