Author Archives: admin

The ‘no win no fee’ risk to employers for hand arm vibration syndrome (HAVS) claims, and what the REAL costs may be

If you have employees using powered vibratory hand tools with poor protective controls in place, then they may be at risk of contracting hand arm vibration syndrome (HAVS). HAVS is a debilitating injury and maybe career ending if its symptoms are not addressed at an early stage.

According to insurers, civil claims are probably the most significant risk to a business associated with hand arm vibration exposure. A quick Google search on “hand arm vibration syndrome” will throw up websites and Google Ads about making claims through “no win no fee”.

We’re all familiar with “no win no fee” in the world of car accidents, but it has now entered and growing in the sector of industrial accidents too. Rightly or wrongly, the employee (especially disgruntled ones who are motivated to do so), or ex-employees can so easily start a claim with a click of a mouse button or a phone call.

“Claims can’t happen to us!”, you say. Or can they?

Avoiding claims

Closing your risk gaps by ensuring regulatory compliance, implementation of best practice methods, and robust safe systems of work are key to preventing injury. These will be examined by legal representatives before deciding to pursue the case. If they’re all watertight, then the case can be rejected from the outstart. This is highly likely to deter bogus, time-wasting claims too.

Defending claims

If appearing in court, defending the case should be straightforward as long as you can prove you’ve appropriate protective mechanisms in place. You should be able to prove that any HAVS injuries arose due to the claimant ignoring your safe systems of work and risk controls, and not through your negligence.

The consequences of a failed defense

Where your evidence of safe systems of work and risk controls are poor or non-existent, then you’re likely to fail. Sure, your insurance will pay out the claim (known as the INSURED cost) should you lose. After all, what do you pay your premiums for? But beware of the tsunami of costs up ahead. Are you aware of these?

What are they, you ask?

They’re UNINSURED costs that kick in and are unavoidable. The insurance DOES NOT cover these costs. Some examples of these are:

  • Lost productivity
  • Sick pay
  • Replacement staff
  • Overtime
  • Increased insurance premiums
  • Court costs
  • Insurance excess
  • Training and re-training costs

The HSE carried out an investigation (HSG245 – Investigating accidents and incidents) and estimated the uninsured costs to be a multiple of the insured costs by a factor of 8 to 36 times!

So, if a typical HAVS claim is in the region of £10-15k (which is not unusual according to a Top 10 Global insurance company), the uninsured cost to you is likely to range from £80k to £540k.

Additionally, think about the non-financial losses like reputational damage, failure to retain or recruit good employees, and decreased morale. These will inevitably be felt financially, and as a result, it could end up costing you even more than just the uninsured costs alone!

Protecting your organisation

How well equipped are you to successfully repel a court claim?

  • Have you determined your risk gaps (your risk assessment, if you’ve carried one out, should tell you this)?
  • Depending upon your findings, you may have to provide your employees with awareness training and health surveillance, and in some extreme cases even stop work. Have you determined these?
  • Do your vibration controls reduce exposure to as low as reasonably possible to minimise the risks of HAVS injuries? How compliant is your organisation with the vibration regulations?
  • Have you a suitable purchase policy for efficient tools? You should also have in place other best practice policies to minimise vibration risks (e.g. when to replace worn consumables).
  • Have you recorded and documented all your actions and processes?

The courts will require you to produce evidence of all this when defending.

How we’ve helped

A manager of a small metalworking business had concerns about the possibilities of litigation in his organisation. The business carried out a risk assessment and asked Essel to sanitise their vibration measurements. However, they had failed to carry out the measurements using guidance in accordance with the correct international standards and also failed to use approved measuring instrumentation. This resulted in invalid measured vibration results and consequently an invalid risk assessment too.

They requested us to carry out a competent risk assessment which helped identify their risk gaps. We made recommendations on how to close these risk gaps to minimise the risks of injury and to be legally compliant.

We recommended the introduction of a purchase policy for acquiring more efficient tools (preferably by trialling the tools first), and to also implement best practice by giving high priority to tool maintenance and servicing (they were severely deficient in this area). We also provided awareness training to operatives which included making them aware of their own legal obligations to minimise the risks of injury (you should know that employees have obligations too).

The business was made aware of what documentation and records to hold in the event of civil claims. The outcome of the whole exercise was that they felt they were confident enough to defend successfully against threats of litigation.

Some free advice here. If you’re thinking of using PPE in the form of anti-vibration gloves to minimise exposure to vibration, forget it. They offer very little protection against injury and their use will not favour your defence.

If all this sounds too daunting for you to do it yourself, simply contact us below for help.


phone: 07710 356663



The Human Cost of Hand Arm Vibration Syndrome (HAVS) – How it affected this man’s life

A hard hitting video shows an example of how HAVS has severely affected this man’s life and very much disrupted his family’s daily routine, a routine that many would take for granted. See the following video:

(Please excuse the quality, but the story is really relative to the subject)

This video appears to be 10 years old (originating from New Zealand) where perhaps there was less awareness to HAVS at the time. Thankfully, today we are more aware of this illness but HAVS cases do occur and the penalties appear to be even more severe (nearly £0.5 million in a recent prosecution).

Cast aside, for just a moment, the fear of prosecution and stinging fines. Ask yourself this question: Is it morally acceptable for staff to go home in a less healthier state than when they turned up for work?

If your employees are regularly using power tools (eg. angle grinders, impact wrenches and hedge trimmers) for prolonged periods, then they may be at risk from developing HAVS.

So what should you look to do next?

If you have had a risk assessment carried out (by someone competent), it should have recommended controls to implement for offering protection against HAVS. Do ensure that the recommendations have been implemented.

A free guide to conducting a hand arm vibration (HAV) risk assessment is available for download. It explains, amongst other things, when you should carry one out, and what constitutes a competent risk assessment. Click here to receive it.


Hand Arm Vibration (HAV) measurements – are you performing them correctly?

If there’s something that is currently controversial in the world of HAV measurements, then it has to be concerned with the placement of the sensor or accelerometer when carrying out measurements. This controversy arises because some measurements are taken with the accelerometer either wrist or glove mounted, instead of being mounted firmly and directly on the vibrating surface of the tool, which is what the relevant international standards specify.

The HSE have included a statement about accelerometer location in a Q and A publication with respect to HAV in the workplace.

Where you place the accelerometer could invalidate your results when carrying out vibration measurements and for determining daily exposures against the exposure limits of the Control of Vibration at Work Regulations (2005). Employers are legally obliged to comply with these regulations.

What DO the HSE publication and Control of Vibration at Work Regulations (2005) say about the sensor placement positions for measurements?

The HSE publication (8 Questions about Vibration Exposure Monitoring) (see  (Question 7) states that “Any measurement away from the palm of the hand or where the measurement position is on the back of the hand, fingers or wrist is unlikely to provide reliable measurement. Further advice is given in BS EN ISO 5349-2:2001. There is currently no wrist or glove mounted device which measures vibration suitable for use in a vibration risk assessment...”.

The Control of Vibration at Work (2005) Regulations makes reference to the standards as per the following:

Under the heading “Vibration measurement and instrumentation” (paragraph 281), it states: “Anyone making hand-arm vibration measurements should be familiar with BS EN ISO 5349-1:2001 and BS EN ISO 5349-2:2002 which contain detailed practical guidance on measurement of vibration in the workplace.”

BS EN ISO 5349- 2 contains the clause: “The accelerometers should be rigidly attached to the vibrating surface”. It is important to note that the action and limit values in the regulations are based upon measurements performed in accordance with these BS EN ISO Standards.

Measurements conducted with accelerometers that are mounted elsewhere other than on the tool’s vibrating surface, or tool handle, could produce significantly different results. This may impact the outcome of any court cases with possible expensive consequences.

Risk assessments

When carrying out vibration measurements either in house or by hiring external expertise, you should ensure that this exercise be carried out in accordance with BS-EN-ISO 5349 parts 1 and 2 for compliancy against the regulations. Make this clear to the assessor.

Looking ahead

Further research however, upon alternative methods of hand arm vibration measurement with respect to accelerometer placement should be encouraged as technology advances. If the outcome of such research is accepted by leading experts and recognised organisations that exert influence on the standards and regulatory committees, then the standards and regulations can evolve and therefore be amended accordingly.

Until then you should look to measurements being conducted in accordance with BS EN ISO 5349 parts 1 and 2 standards to comply with the regulatory and HSE requirements.


A free guide to conducting a hand arm vibration (HAV) risk assessment is available for download. It explains, amongst other things, when you should carry one out, and what constitutes a competent risk assessment. Click here to receive it.

Cold weather and Hand Arm Vibration Syndrome (HAVS)

As winter approaches, employers should look to provide staff protection against the onset of the cold weather when using power tools implicated in HAVS, either outdoors or indoors in inadequately heated areas. HAVS is a debilitating illness caused by prolonged use of hand held and hand guided power tools, and it consists of a number of symptoms affecting the blood circulation, nervous system and muscles and bones in the hand and lower arm.

Employers are duty bound under the Control of Vibration at Work Regulations (2005) to prevent employees from developing this illness.

Impaired blood circulation in the long term could lead to Vibration White Finger (sometimes known as Raynaud’s syndrome) where the fingertips go white in cold environments and slowly (often painfully) recover to normal in warm areas. If left unchecked there may be no recovery making the illness permanent.

HAVS can be exacerbated by using powered tools in cold and damp weather and has the potential to develop even more rapidly the colder it gets.

Employers must encourage staff working in cold conditions to keep warm and maintain blood circulation by providing the right protection, like warm clothing and gloves. It should be noted that there is no effective PPE for HAVS and so-called anti-vibration gloves are more beneficial for keeping hands warm than as a means of reducing vibration exposure. Employees are also to be encouraged to take more breaks, massage hands and fingers to stimulate blood circulation, and drink warm beverages as examples of further preventative measures.

competent HAVS risk assessment should take into account the working conditions of employees when using vibratory equipment. A free guide to conducting a hand arm vibration risk assessment is available for download. It explains, amongst other things, when you should carry one out, and what constitutes a competent risk assessment.
Click the link here to download the guide.

Essel Acoustics has the skills and experience to help. See contact details below.

Essel Acoustics Satish

Satish Lakhiani

Satish Lakhiani MSc, MIOA

Essel Acoustics Ltd
Phone: 07710 356663

£2.5 million worth of HAVS fines imposed upon businesses over the last few years

Repeated exposure to vibration from operating power tools can lead to a condition known as hand arm vibration syndrome (HAVS). HAVS is a collective term given to debilitating disorders of the blood vessels, joints, and connective tissues of the hand and lower arm, and it is irreversible. 

It’s very unfortunate that businesses over the last few years have neglected to protect employees against HAVS injuries, and this has resulted in prosecutions with the imposition of very large six-figure fines in some cases. What is more unfortunate is the HUMAN cost of this injury. Employers are duty bound to protect staff under the Control of Vibration at Work Regulations (2005).

The table below indicates (×), over the last 7 years, the parts of the regulations (reg) that the businesses ignored and this resulted in the prosecutions where total fines excluding costs exceeded £2.5 million. The individual fines are also shown in the table.

YearNature of BusinessFine (excl. costs)Risk Assessment (Reg 5)Health Surveillance (Reg 7)Info, Instruction, & Training (Reg 8)







2018Housing Association£30k








2017Housing Association£100k








2017Local authority£150k





2016Local authority£250k













2015Truck manufacturing£50k







2013Mechanical parts£52k













*Failed to act on the risk assessment carried out
**Failed to act on health surveillance findings

The table shows that the major failure was the result of businesses not carrying out a risk assessment, or one that was neither suitable nor sufficient. Management, including those representing health and safety should be aware that where particular power tools are used for significant lengths of time, then there is a likelihood of HAVS developing. Under these circumstances, according to the regulations, a risk assessment shall be carried out and it must be conducted by either a competent person or a specialist.

A suitable or sufficient risk assessment should be able to determine whether staff are clearly at risk, and if so then one of the outputs of the assessment shall be the provision of health surveillance by the employer. Health surveillance should alert employers to early signs of the illness which may be prevented before progressing to an irreversible state. In the above table where risk assessments were not carried out it would have been highly unlikely that health surveillance was advised or provided.

New Noise & Vibration Consultancy Launches

Another output of the risk assessment shall be the duty to provide suitable and sufficient information, instruction, and training, to operatives. The training would enable staff to recognise the early signs of HAVS and report it in time to prevent development into a permanent state. In the above table where risk assessments were not undertaken, it was also highly unlikely that the employers would have been made aware of their duties to provide suitable information, instruction and training. The onset of HAVS may therefore have gone unrecognised due to lack of awareness.

Employers must ask themselves the following questions: What would the impact be on their business if faced with such penalties, both financially and otherwise? Does the business not have a moral responsibility to protect the staff against such ill health? For a small fraction of the cost could all this not have been avoided?

A free guide to conducting a hand arm vibration (HAV) risk assessment is available for download. It explains, amongst other things, when you should carry one out, and what constitutes a competent risk assessment. Click here to receive it.

HAVS prosecutions: The impact of the Sentencing Council Guidelines

HAVS prosecutions: The impact of the Sentencing Council Guidelines

By now all those concerned with health and safety in their businesses should be aware of the Sentencing Council guidelines to Health and Safety Offences, Corporate Manslaughter and Food and Safety and Hygiene Offences.

These guidelines were introduced in early 2016 and a noticeable outcome has been the draconian level of fines imposed upon businesses for various health and safety breaches since then. Many non-fatality related fines have exceeded £1 million but despite this, businesses still seem to be unaware of the impact of the guidelines.

The guidelines have also had a major effect in industry sectors where staff have developed cases of HAVS, and since 2016 it has not been uncommon for imposed fines to reach six figures for HAVS non-compliance with respect to the Control of Vibration at Work Regulations (2005). HAVS is a collective term consisting of blood vessel damage, nerve and muscular disorders of the hand and forearm, caused by frequent exposure to hand arm vibration through use of powered tools.

For those who need reminding (or for the unaware), this blog looks to explain how the guidelines work and also how the Starting point of a fine may be established. Using a realistic example, these guidelines will then be applied to a fictitious organisation where many employees regularly use powered tools and are at risk of developing HAVS. The purpose of the example is to arrive at an indication of what the starting point of an imposed fine could be for the business if it fails to put effective controls in place.

How the guidelines work

Prior to the introduction of the guidelines, it was felt that the fines handed out to offenders did little to reflect the gravity of the offence, and that not much guidance was available to the courts when passing sentence upon health and safety cases. The new guidelines now aim to ensure consistency and fairness when penalising individuals or organisations for breaches in health and safety.

There’s now a stepped (9 steps in total) approach that considers various factors before deciding the penalties to be imposed on the organisation facing prosecution. The first step considers Culpability (where the factors range from minor failings to deliberate breaches) and the Harm created by the offence (taking into account the seriousness of the risk of harm, the likelihood of harm, the number of people exposed to the risk, and whether harm was actually caused).

For the second step the courts look at the turnover of the organisation to establish a Starting point of the fine. The Starting point of the fine lies within a Category range, and whether it moves upwards or downwards from the Starting point depends upon other examples of factors that are taken into consideration, such as previous convictions, track record of health and safety, and cost cutting at the expense of health and safety.

Steps 3 to 9 look at other influencing factors such as the profitability of the organisation, the impact of the fine on its employees, and guilty pleas in finalising the fine.

Points to note are that:

  • even if no harm took place, it is the risk of harm that is taken into account when deciding the fines to be imposed (you may wish to bear in mind that it only takes a disgruntled or concerned employee, or an ex-employee to alert the enforcement bodies about such risks).
  • the offending organisation could be a company, a partnership, a local authority (in which case the Annual Revenue Budget is looked at as the equivalent of turnover), a health trust, or a charity.
  • the judge may consider it necessary to move outside of the suggested category range to achieve a proportionate sentence, if the company is a very large organisation.
  • when arriving at the fine the message that the courts want to convey is that it must be “sufficiently substantial to have a real economic impact which will bring home to both management and shareholders the need to comply with health and safety legislation.

The starting point of a fine in an organisation where staff may be at risk from HAVS

An example of how the starting point of a fine may be predicted is shown by considering a fictitious business ABC Manufacturing Ltd. This business has an annual turnover of approximately £8 million and 12 members of staff use powered tools (angle grinders, drills, circular saws, etc.) implicated in causing HAVS. These tools are used regularly and for long periods on a daily basis.

Through what seems to be a lack of awareness, no risk assessments, methods of vibration control, staff training, or health surveillance have been provided or made available to mitigate against the risks of HAVS developing. ABC Manufacturing looks to be a ripe candidate for prosecution even though no injuries have been reported. What could the Starting point of the fine be if this business lands up in court? It is possible to predict this by applying the Sentencing Guidelines.

Step 1 determines the offence category by firstly assigning both the Culpability and the Harm.


Figure 1 – Categorisation of the Culpability taken from the Guidelines

ABC Manufacturing Ltd look to have no controls (through lack of awareness rather than deliberately) in place for mitigation against HAVS. With reference to Figure 1, High Culpability may be an appropriate categorisation, justifiably, because the business looks to have fallen “…short of the appropriate standard, for example by failing to put in place measures that are recognised standards in the industry”. The next step is to consider Harm.


Figure 2 – Categorisation of the Harm taken from the Guidelines

Refer to Figure 2. HAVS, once contracted, is “A progressive, permanent, or irreversible condition”, so Level B may be selected in terms of Seriousness of harm risked. As the employees in ABC Manufacturing use highly vibratory tools on a regular basis, and with no form of HAV risk controls in place, it may be validly judged that there could be a High likelihood of Harm occurring. It would not therefore seem unreasonable for the courts to select the Initial harm category (paragraph 1) as Harm Category 2.

As there are 12 employees exposed to the HAVS risk, the risk of harm may be considered higher (paragraph 2), therefore the courts could decide to either move up a Harm category or substantially move up within a Category range. For the purpose of the example, Harm Category 1 shall be chosen as the Final Harm Category.

Step 2 identifies the size of the business according to the turnover, and then arrives at a Starting point of the fine and its Category range.

Figure 3 – Starting point and Category range for Small and Micro organisations taken from the Guidelines

The turnover of ABC Manufacturing Ltd is £8 million, therefore from Figure 3 ABC Manufacturing may be classified as a Small organisation (i.e. a turnover of between £2 million and £10 million).

With High Culpability, Harm Category 1, and a turnover of £8 million, this would give a Starting point of the fine as £250k. The final amount (which could be anywhere between £170k and £1million in the Category range) as mentioned before depends upon the outcome of carrying out steps 3 to 9.

Note that if actual harm DID take place then the courts would be entitled to move the Starting point of the fine upwards within the Category range (see Figure 2, bottom paragraph).

As previously mentioned, the courts are also entitled move outside of the suggested Category range for very large organisations.

For reference, another table for different sized organisations is shown in Figure 4. This shows the Starting points of the fines and the Category ranges for businesses with larger turnovers than the example used for ABC Manufacturing.

Figure 4 – Starting point and Category range for Medium and Large organisations taken from the Guidelines

HAVS prosecutions since 2016

Below are some examples (with links to webpages) of six figure fines imposed upon organisations that were prosecuted for the occurrences of HAVS (i.e. actual harm caused) since the introduction of the Sentencing Guidelines in early 2016.

The message is quite clear. Organisations have only to put workers’ health and safety at risk for courts to act mercilessly by imposing heavy fines, and these fines now also take into account the size of the business. It’s worth noting that if there are breaches and the HSE get inevitably involved, IN ADDITION to the fines, the organisation has to take into account:

  • its legal fees
  • the HSE’s legal fees
  • the HSE’s fees for intervention (currently standing at £154 per hour)

So to do nothing is by far the biggest risk you are taking!

What can you do about it?

If you have a risk assessment (carried out by someone competent) in place, it should have recommended controls to implement for offering protection against HAVS. Do ensure that the recommendations have been implemented.

However, if you are unsure on how to carry out a risk assessment, a free guide to conducting a hand arm vibration risk assessment is available for download.
It explains, amongst other things, when you should carry one out, and what constitutes a competent risk assessment. . Click here to receive it.

An alternative approach for predicting the hand arm vibration (HAV) daily exposure

If powered tools are extensively used in your organisation and you think employees are potentially at risk of injury to their fingers, hands and arms, known as HAVS, then you are obliged to carry out a HAV risk assessment. This exercise will require you to get a good estimate of the operative’s daily exposure known as the A(8) value, and there’s a very useful online HSE spreadsheet which may be used for this purpose.

The A(8) value can then be compared against the exposure action & limit values as stated in the Control of Vibration at Work Regulations (2005), and if there is an issue, risk controls may be applied accordingly. The spreadsheet is also capable of predicting the maximum allowable tool trigger (usage) times before hitting the exposure action and limit values.

What if you find yourself in a position where you are not within easy access of the HSE spreadsheet and wish to estimate A(8), or indeed the maximum allowable trigger times for a tool? You may be on your shop floor or out in the field carrying out vibration level measurements where it’s not so convenient to return to your desk.

Don’t despair. All you need is a calculator (your smartphone should have one) and to apply the following simple equation (it’s stated in the regulations and worth memorising):

VEP per hour = 2v2

Where, VEP = the HSE vibration exposure points

And, v = tool vibration level (in m/s2) [this value may be obtained through measurement, from manufacturer’s data, or from a reliable database].

You should also be familiar with working in terms of VEPs, where A(8) = 100 VEP equates to the action value, and A(8) = 400 VEP equates to the limit value.

To estimate A(8),

  1. Start off by inserting a value for v into the equation, to obtain the VEP per hour.
  2. Next, multiply the VEP per hour by the trigger time (expressed in hours) provided by the operative, to predict the VEP for the particular tool.
  3. For multiple tool use daily, simply sum up the VEP for each tool to predict the overall A(8).

Refer to the worked example below, where 2 tools, A and B, are used on a daily basis by an employee:



Vibration level, v (m/s2) VEP per hour [=2v2] Daily Trigger time (hours)

VEP [=VEP per hour x Daily trigger time]


4.5 41 2 82


6.7 90




The exposure action value (100 VEPs) has therefore been exceeded (A(8) = 217 VEP). As a result, there are specific obligations to fulfil  in accordance with the regulations when reaching the exposure action value.

It is also possible to predict the trigger times taken to reach both the exposure action and limit values for any tool. These are mathematically expressed as 100/(VEP per hour) and 400/(VEP per hour) respectively.

So for tool A in the above table, the trigger times taken to reach the exposure action and exposure limit values would be given by 100/41 (= 2 hours 26 minutes) and 400/41 (= 9 hours 45 minutes), respectively.

Like wise for tool B, the trigger times taken to reach the exposure action and exposure limit values would be given by  100/90 (= 1 hour 6 minutes), and 400/90 (= 4 hours 24 minutes) respectively.

This equation is simple, but powerful, and allows you to use an alternative and convenient method to determine the daily exposure (plus allowable tool trigger times) if the HSE spreadsheet is not easily accessible. It’s an equation that’s worth memorising.


A free guide to conducting a hand arm vibration (HAV) risk assessment is available for download. It explains, amongst other things, when you should carry one out, and what constitutes a competent risk assessment. Click here to receive it.





Avoid Hand Arm Vibration Syndrome (HAVS) – Replace a hazardous process with a non-hazardous one

Here is a great video which shows how advancement in modern technology has negated the need for chainsaw use when logging/felling, and demonstrates the replacement of a hazardous hand arm vibration process with a non-hazardous one.

See the following video:

It would set a fine example for the business to demonstrate to their staff a method of risk control that they have implemented when providing HAV Information, Instruction and Training (IIT). The provision of IIT is an obligation if staff are shown to be at risk from HAVS.

When should IIT legally be provided, who should provide it, and what items should be provided in the training?

You have an opportunity to find out by receiving. Click here to download your free copy.

Manufacturers’ vibration emission data for tools and equipment – Be cautious of using it for Hand Arm Vibration (HAV) risk assessments!

Essel Acoustics Occupational Vibration FeaturedIt’s likely that the widespread publicity about six figure fines for health & safety breaches has provoked employers to carry out a HAV risk assessment. Caution should, however, be exercised when using manufacturers’ declared vibration values of tools or equipment for determining the Daily Exposure A(8). It is important to understand how this data originates otherwise there is a possibility that staff exposure to vibration may be underestimated, increasing the risks of HAV related injuries such as carpal tunnel syndrome or vibration white finger.

Manufacturers who produce tools or equipment that emit potentially harmful vibrations are obliged, under The Supply of Machinery (Safety) Regulations (2008), to declare vibration emissions along with other safety related information.

The manufacturers’ declared vibration emission values are usually obtained in accordance with harmonised European or international vibration standards, and in the UK these standards are published as British Standards. Test methods described in these standards are laboratory type tests applied in a careful and controlled manner to tools and equipment, so that a repeatable evaluation of vibration emissions may be determined.

In the real world workplace, however, the test conditions are very different to the controlled ones during manufacturers’ testing, which could lead to very different measured results. Generally speaking field measurements tend to be higher than laboratory acquired ones. There are many factors that affect the measured results in the field:

  • tools or equipment used in the field might be aged and worn
  • how worn out the consumables may be e.g. the sharpness of cutting edges and drill bits
  • the type of workpiece encountered in the field
  • operator technique

Manufacturers’ declared emissions data is still very useful when comparing vibration emissions of tools of the same type, enabling informed purchase decisions to be made; the vibration equivalent of ‘buy quiet’.

A word of caution: the comparison process must take into account the efficiency of tools for the operations concerned, as using a low vibration specified tool may lead to overall increased exposures if the task takes longer as a result.

A free guide to conducting a hand arm vibration (HAV) risk assessment is available for download. It explains, amongst other things, when you should carry one out, and what constitutes a competent risk assessment. Click here to receive it.

Hearing protection – Do not remove it, even briefly, in high noise environments!

Hearing protection – Do not remove it, even briefly, in high noise environments!

So, you have predicted that the hearing protection worn by staff in your workplace provides the correct amount of attenuation, but what happens if these devices are removed even for a short period of time whilst in a high noise environment? How does it impact the hearing protector’s effective attenuation?

If a hearing protector is not worn for 100% of the time in a noisy environment, then its effectiveness decreases rapidly. The graph below shows the reduction in effectiveness of a hearing protector that is removed for a period of time expressed as a percentage of the total time that the user is exposed to the noise. Three different hearing protectors each of varying degrees of protection are represented in the graph.

Effectiveness of HP trial

When all 3 hearing protectors are worn for 100% of the exposure time the effective attenuation is as predicted (i.e. 30dB, 20dB, and 10dB respectively for all 3 of them). However, if the 30dB rated hearing protector is worn for 98% of the exposure time (or removed for 2% of the time), then the effective attenuation drops by approximately 12dB. As an example, for a noise exposure period of 8 hours, this would imply that removing a 30dB attenuation rated hearing protector for nearly 10 minutes would give only about 18dB of hearing protection!

By comparison, the drop in effective attenuation is only 1dB to 2dB when the lowest rated hearing protector (offering 10dB protection) is removed for 2% of the time that the wearer is exposed to noise.

When all the 3 types of hearing protectors are unworn for 50% of the noise exposure time, then the effective attenuation is 3dB only for all of them.

Another surprising observation as you can see in the graph below, is that the hearing protector offering 10dB of attenuation, if worn (correctly and consistently) for 100% of the time, will provide just as much protection as both the potentially more expensive 20dB and 30dB rated hearing protectors worn for 90% of the time (for an 8 hour noise exposure period, this is equivalent to not being worn for 48 minutes).

Effectiveness of HP trial 2

The important lesson is…

Employees must understand the importance of wearing hearing protection before entering an area of high noise, and that when hearing protection is removed even briefly whilst in noisy environments, the effectiveness of the hearing protector can be severely reduced. This attaches great significance to selecting comfortable hearing protection (appropriately rated, of course) as the temptation to remove it is substantially reduced. Giving employees a choice of protectors also helps with wearer compliance.

Download a free guide to see what a good noise risk assessment must consist of. This guide also explains why overprotective hearing protection can be hazardous in the workplace. Click here to receive the guide.