This week, the Court of Appeal handed down judgment in Bowe v Mersey Rewinds Engineering Ltd. & Ors  EWCA Civ 72, an employer’s liability HAVS case heard in July 2017. The Court of Appeal found that infrequent and transitory exposures to vibration above daily guidance threshold limits did not give to a foreseeable risk of injury at common law and so the claim failed on breach of duty.
The claimant alleged he had developed vibration white finger (VWF) and carpal tunnel syndrome (CTS) from the use of vibrating tools and exposure to excessive vibration during various employments with the 3 defendants as an armature winder from 1986 until the date of first trial in 2014.
All of the defendants admitted to failing to take any steps at any time to warn, advise or monitor the claimant in respect of the potential health effects of working with vibrating tools. However, they denied allegations that the claimant was subject to frequent or prolonged vibration exposure. The 1st and 3rd defendants resisted the claim on limitation, while all three defendants contended breach of duty, in their defence.
During the claimant’s exposure with the 3 defendants, the Guide to Measurement and Evaluation of Human Exposure to Vibration Transmitted to the Hand, BS 6842:1987 was the appropriate guidance for assessment of vibration exposure. The basis of measurements was daily exposure, expressed in terms of the energy equivalent frequency weighted acceleration (EEFWV).
The above table, found within the BS 6842 Guidance, shows that if daily exposure remains constant, as lifetime exposure in years progressively doubles, the vibration level expected to produce finger blanching in 10% of exposed persons halves. Manufacturers are guided by table 5 when designing machines. Nonetheless, the relationship between prevalence and vibration exposure is limited, due to a shortage of available data.
Within the ‘General Considerations’ section of the Guide, there is a list of factors which may influence the severity of the effects of hand-transmitted vibration.
Moreover, the Health and Safety Executive produced the publication, HS(G) 88, Hand-Arm Vibration, 1994, which delivered guidance for parties bound by the Health and Safety at Work Act 1974. In paragraph 21 of the guidance, it states:
‘Programmes of preventive measures and health surveillance are recommended where workers’ exposure regularly exceeds an A(8) of 2.8 m/s2’.
This is a direct reference to Table 5 of the BS 6842 Guide, in which 10% of persons exposed to an 8 hour daily dose could be expected to produce finger blanching after 8 years of lifetime exposure. The ‘A(8)’ is a daily vibration dose of exposure to vibration which is dependent on vibration levels and duration of exposure (analogous to the daily noise dose Lep.d) and calculated using the formula:
While it is widely accepted that an A(8) of 2.8 m/s2 is the ‘action level’ for vibration, 1 m/s2 is the ‘threshold level’ for vibration. If the A(8) exceeds 1.0m/s2, then courts have previously held this gives rise to a foreseeable risk of injury. Employers may then owe a duty of care to at least warn employees of risk and to recognise and report any symptoms as they develop, and to monitor employees for likely symptoms. Both of these ‘levels’ are relevant to the Bowe case.
THE LAW ON SAFE LEVELS OF EXPOSURE
In the case of Armstrong v British Coal Corporation No 2, 31 July 1998 unreported, Judge LJ ruled that there existed a duty to warn employees about the risk of VWF developed through the use of coalmining vibratory tools. He stated:
‘If you are working with vibrating tools and you notice that you are getting some whitening or discolouration of any of your fingers, then in your own interests you should report this as quickly as possible. If you do nothing, you could end up with some very nasty problems in both hands’.
Seemingly adopting guidance in BS 6842, it was interpreted, albeit implicitly, that guidance intended for advice to be given to employees who use vibrating equipment on a ‘regular’ or ‘frequent’ basis.
Further, in the case of Doherty and others v Rugby Joinery (UK) Ltd  EWCA Civ 147, Hale LJ reasoned:
‘It is clear from both documents that the state of knowledge was not sufficient to lay down a safe standard of exposure. The variables were too complex, and included individual susceptibility. Thus, it could be suggested that any employer whose employees regularly used hand-held vibratory tools should at the very least take steps to warn them of the possible dangers and advise them to report any symptoms when they occurred’.
The experts in Bowe were in agreement that ‘if the claimant’s account of his usage of vibrating tools was accepted then it was very likely that he had been exposed to “a hand/arm vibration dose exceeding the action level on a regular basis dependent upon the actual duration of his average working day”’.
The experts also agreed that ‘if the defendants’ account ... of his usage of vibrating tools was accepted “then it is highly likely that the claimant was not exposed to significant hand/arm vibration”’. ‘Significant’, in this context, meant ‘exposure to a hand/arm vibration dose exceeding the threshold level’.
THE 1st INSTANCE TRIAL
At first instance, in February 2015, the Recorder dismissed the defendants’ limitation defence, as, in accordance with s.14 of the Limitation Act 1980, the claimant’s date of knowledge was deemed to have fallen within the three year period before proceedings were issued. As such limitation was not included within the defendants’ grounds for appeal in the present case.
Then, on the subject of breach of duty, the Recorder was satisfied that the claimant had deliberately exaggerated the extent of his vibration exposure. In fact, the claimant was not required to use vibrating machine tools as an armature winder and only carried out activities of fitters on an infrequent basis, comparative with armature winding. While carrying out fitting tasks under the employment of each of the defendants, the Recorder found that the use of needle guns and air chisels was necessary, ‘both of which reached the threshold level in a relatively short period [3 minutes] of time’. The needle gun was used irregularly for ten minutes at a time. Evidence was presented to the judge, as follows:
He observed that:
- Below 1 m/s2 (threshold level) – there was no foreseeable risk of injury resulting from exposure to vibrating tools and employers owed no duty of care at common law.
- Above 1 m/s2 – employers owed a duty under common law, and later, pursuant to the Control of Vibration at Work Regulations 2005, to take some steps to alert employees to the potential risk of injury by warning, monitoring and advising employees using vibrating tools.
- Above 2.8 m/s2 (action level) – employers must take active steps, such as reduction of exposure by modification of tools, job rotation, etc.
The Recorder found in favour of the claimant, ruling that each defendant ‘“transitorily” exposed the claimant to vibration speeds above what is known in the industry as “the threshold level”’, without warning the claimant about employment-based risks, monitoring exposure, or providing advice. Further, the Recorder decided that the level had been breached on occasion, or time to time, and hence, there had been a ‘limited’ breach of duty ‘in relation to the requirements either at common law or later pursuant to statute following such a breach of the threshold limit’.
This finding was subject to appeal in the latest hearing, in January of 2018.
Thirlwall LJ, handing down judgment, said at paragraph 17, of the Recorder’s ‘limited’ determination on breach, that:
‘The recorder did not determine what the consequences would have been had the claimant received an appropriate warning or advice or there had been some monitoring ... the recorder characterised his finding of breach as limited. Its effect was likely to be very limited; given that the claimant was still working at the time of the trial, knowing of his condition, knowing the medical advice and knowing of the basis of his claim. Since the recorder made no findings I say no more about it’.
The judge identified, at paragraph 19, that:
‘The question of law ... is whether, having found that the claimant was transitorily exposed to levels above the threshold, the recorder was entitled to conclude that this (combined with the admitted failure to warn etc) meant that each of the defendants was in breach of duty’.
She went on to agree with the defendants’ submission that:
‘... “transitory” (and I would add for the purposes of the argument, occasional) exposure to levels above the threshold does not automatically lead to a finding of breach of duty’.
So, could it be concluded that the exposure, while not at the action level, but above the threshold level, was, in the admitted absence of any warning, tortious?
Defendants’ counsel submitted that the Recorder had misunderstood that the assessment of vibration exposure is primarily based on the measurement of daily exposure, and was wrongly inferenced by claimant counsel’s argument that ‘30 minutes exposure to a needle gun once a fortnight equates to 3 minutes per working day’.
Thirlwall LJ asserted that the Recorder:
‘... was not wrong to conclude that if a needle gun was being used, the threshold level was reached after 3 minutes. However, whether there was a breach of duty depended on the frequency of the use of the needle gun and/or the air chisel and he made no findings about that. He did find that the tools were used over many years’.
When reaching a conclusion on the ‘frequency’ of use, as a means to finding breach of duty, the judge stated, at paragraph 21:
‘There are two problems with the approach in respect of the fortnightly use of the needle gun: first there is no expert evidence to suggest that a single occasion of 30 minutes exposure equates to 3 minutes on 10 occasions. Second, and more importantly, the recorder made no finding that the claimant used the needle gun once a fortnight or at any other level of frequency or regularity nor did he make any findings about the frequency of use of the air chisel’.
Bringing the judgment to a conclusion, Thirlwall LJ surmised, at paragraph 23:
‘At its highest the recorder found “transitory” exposure above the threshold. In the absence of any finding as to frequency and any expert evidence about the effect of intermittent use at such a frequency it was not open to the recorder to move from a finding of transitory exposure even over many years to a conclusion that this constituted a breach of duty by the defendants. To come to that conclusion he would have had first to find that the claimant was using the needle gun and/or the air chisel at or above the threshold level on a regular/frequent basis and it was in that situation that there had been no warning, advice, monitoring etc. He did not do so because he was rightly not satisfied on the evidence that the use of vibrating tools was either regular or frequent. The evidence was all the other way’.
Thus, Thirlwall LJ overturned the Recorder’s ruling, at first instance and allowed the appeal, with Moylan LJ and Asplin LJ also in agreement.
Sufficient frequency and regularity of vibratory tool use, therefore, are vital to finding breach of duty, even where it is established that the threshold level of exposure of 1.0m/s ² is met. ‘Infrequent’ and ‘transitory’ exposure, according to the Court of Appeal in Bowe, is not enough to make it reasonably foreseeable that an employee is at risk of injury if vibration exceeds the ‘action level’ or ‘threshold level’.
The same principle, arguably, would extend to NIHL claims. Infrequent and transitory exposure above common law thresholds of exposure would not give rise to a breach of duty as they would not create a foreseeable risk of injury. Certainly, they would invite strong causation arguments. The principle is also addressed with statutory regulations on noise. So, for example, within the Control of Noise at Work Regulations 2005, Regulation 4(4) allows you to calculate exposures over a week rather than a day in circumstances where noise exposure varies from day to day. Use of the weekly average may be appropriate where exposures are infrequent and transient but also involve modest exposures just above exposure action values. So, it would not be suitable where exposures involved very high exposures - albeit infrequent and ‘transitory’.
The full text judgment of Bowe can be accessed here.