Category Archives: News

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?

You should consider carrying out a HAV risk assessment. To find out what constitutes a good, or suitable and sufficient risk assessment, Essel Acoustics has a downloadable free guide explaining this. Click here to download your free copy.


Staff not always wearing hearing protectors? Sound restoration hearing protection may be a solution

It is commonplace in noisy workplaces to see that earmuffs provided by employers are either being improperly worn or not worn at all.  The frequent complaint (from staff) is that the ear protectors are overprotective in areas that are not continuously noisy, and that this results in poor situational awareness.  Situational awareness is critical for avoiding accidents and possibility fatalities too.  The comment from employees “better deaf than dead” is one that is often heard by Health and Safety managers.

So how can you satisfy the requirements of a hearing protector with the right amount of protection, but not so excessive to make it inaudible to warning or danger signals (e.g. vehicular alarms, equipment malfunction noises), and also to quiet electrically powered vehicles in your workplace? Are you aware that the technology exists commercially in the world of hearing protection to fulfil these needs?  If not, read on.

Sound restoration hearing protection is now available, which, in its most usual form, comes as an earmuff incorporating electronic circuitry plus audio components. The basic operational principle is that it protects against high ambient noise but permits communication and situational awareness during quieter periods.

Miniature microphones mounted on the earmuff pick up low level non-hazardous ambient sounds (which could be warning signals or alarms that need to be heard) and after electronic processing, naturally reproduces these sounds internal to the earmuff via miniature ‘speakers.  This makes it unnecessary to remove the earmuff.  As the ambient sound gets dangerously louder (or even suddenly loud) a compression facility designed in the electronics ‘clamps’ or limits these noises to safe levels at the wearer’s ears.

The benefits of such a hearing protector are two fold i.e. situational awareness together with protection against harmful noise levels.  As the ambient noise gets even louder, the noise breaking into the earmuffs will eventually increase and be determined by the passive attenuation characteristics of the hearing protector.

So providing the earmuff is comfortable to wear, the chances are that this type of hearing protector is likely to stay worn by staff who require both situational awareness and safe hearing protection.  Many of the leading hearing protection manufacturers include such a product in their portfolio.

Essel Acoustics can carry out a noise risk assessment in your workplace and identify appropriately rated hearing protection, and the need for sound restoration types too.  What else should a noise risk assessment consist of?  Click the link below to find out by receiving a free downloadable guide (which also includes a section on hearing protector overprotection)

Download the FREE guide to Overprotection and Noise risk assessment here

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.

Other IIT examples to explain to staff as implemented risk control measures are as follows:

  • training of operators to use equipment with grip forces which minimise vibration transmission.
  • to encourage the reporting of equipment in poor condition which can generate higher vibration levels.
  • reducing exposure time by an organisational process, i.e. ‘job rotation’.

What else should be included in HAV IIT? You have an opportunity to find out by receiving a free downloadable guide. Click here to download your free copy.

Hand Arm Vibration Syndrome (HAVS) – the effects on businesses

Hand Arm Vibration Syndrome (HAVS) – the effects on businesses

Nowadays there is increased awareness of HAVS in industry, but despite this, some businesses still have lack of a meaningful strategy in place to deal with this potential health problem. The Control of Vibration at Work Regulations (2005) places legal duties on employers to protect staff at risk from HAVS.

HAVS is a debilitating and compensable injury caused by frequent exposure to vibration emissions through the use of power tools, for example, angle grinders, impact wrenches, air chisels, strimmers and hedge cutters. If left unchecked, excessive use of such equipment will eventually lead to irreversible damage of the blood vessels and tissue in the hand and arms.

If your business is one that hasn’t given HAVS much thought, or if it has but without a robust plan to deal with it, then take a few minutes to consider the impact of the lack of action should any HAVS related problems arise. The impact is not only a financial one, but it has other effects too.

The many points to consider are listed below.

Financial impacts

  • Payment of salary on sick leave
  • Litigation (think ‘no win no fee’)
  • Costs of medical treatment
  • Early retirement and pension costs
  • Fines/penalties imposed by enforcement agencies

Hand Arm Vibration Syndrome (HAVS) - the effects on businesses headlines

  • Compensation costs
  • Costs to cover for redeployment of internal staff or use of agency supplied staff
  • Overtime costs
  • Legal costs
  • Lost contracts or penalty clauses on delayed contracts
  • Investigative and monitoring costs
  • Increased liability insurance premiums

Other impacts

These might be difficult to quantify fiscally but would certainly be felt by the business.

  • Decreased productivity due to staff being absent for prolonged periods
  • Temporary or new staff (if inexperienced) requiring training or management
  • Lower morale of workforce
  • High turnover of staff
  • Bad publicity in press
  • Failure to attract new employees
  • Other businesses unwilling to outsource work/processes to yours as a result of your poor safety record

Also, do not underestimate the management costs in many of the above items listed. But above all what about the HUMAN cost!

What can you do about it?

A good starting point for best avoiding the above listed ‘headaches’ would be to consider carrying out a HAV risk assessment. Essel Acoustics has a downloadable free guide that explains how to recognise the need to carry out a HAV risk assessment and what constitutes a suitable and sufficient risk assessment. Click here to read more and download our FREE guide.

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.

A competent HAVS risk assessment should take into account the working environment conditions of staff when using powered equipment. To see what other factors that should also be taken into account when carrying out a risk assessment, click the link below to download our  FREE guide “A guide to conducting a Hand Arm Vibration Risk Assessment”.

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

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.

There are further points that must be taken into consideration when conducting a suitable and sufficient risk assessment, and these are shown in the FREE guide “A guide to conducting a Hand Arm Vibration Risk Assessment”.

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

The SNR of a hearing protector – what does it mean, and how do you use this figure to determine the noise protection provided?

Printed on the packaging of a CE approved hearing protector, you may have seen a quantity known as the Single Number Rating (SNR) denoted in decibels and wondered “what is it, and how is it of any use”?

The SNR is a single attenuation value which is quite often sufficient enough and can be manipulated easily to estimate the protection provided by a hearing protector against exposure to noise. It is a convenient figure to use particularly if your sound level meter (which must be an integrating one) does not have the facility to take octave band readings, but incorporates a ‘C’ weighting filter.

From the octave band attenuation performance of the hearing protector (derived from a test defined in a BS EN standard), the SNR performance can be calculated (by a method prescribed using a BS EN ISO standard) and be published by the manufacturer.

To predict the noise level at the ear of a person exposed to noise and who is wearing hearing protection, you must first determine through measurement the equivalent continuous ‘C’ weighted sound pressure level of the offending noise. The result is then processed as follows:

LAeq’ = LCeq – SNR

where LAeq’ = predicted equivalent continuous ‘A’ weighted sound pressure level (in dB) at the ear with the hearing protector in place (this quantity allows you to determine whether the hearing protector provides adequate protection).

LCeq = the equivalent continuous ‘C’ weighted sound pressure level of the offending noise field (in dB) as measured by your sound level meter.

and SNR = Single Number Rating of the hearing protector (manufacturer’s data) (in dB)

The Health and Safety Executive (HSE) recommend that a ‘Real World’ factor of +4dB should be added to the predicted result due to factors such as poor fitting, the wearing of spectacles and interference by other forms of personal protective equipment or headwear. As a result, the noise level at the ear is predicted to be 4dB higher than the computed result.

E.g. If LCeq is measured as 108 dB, and the SNR of the hearing protector is 30dB, then LAeq’ would equate to 78dB (i.e. 108dB – 30dB). To account for the ‘Real World’ factors explained in the above paragraph, the noise level at the ear would increase by 4dB to 82dBA.

The HSE also recommend that the hearing protector should reduce the noise level at the ear to below 85dBA. In the case of the above example, the hearing protector of SNR 30dB provides adequate protection at 82dBA.

Note: The LCeq measured quantity is different to an LCpeak one also seen on sound level meters and should not be confused with one another. The latter is a ‘C’ weighted absolute peak measurement where high peak levels may present a risk to hearing from a physical damage point of view. The selection of appropriate hearing protection against such damage uses a prediction method that is different to the one described in this posting.

Although the method used to arrive at the noise level prediction is most accurate when using the manufacturer’s octave band attenuation data of the hearing protector, using the SNR figure to predict the noise level at the ear when wearing a hearing protector gives a close enough approximation in most cases. The exception to this is when the offending noise is particularly rich in low or high frequency content, and caution must therefore be exercised when this situation arises. Under such circumstances it would be advisable to use the octave band attenuation data for the prediction, along with an octave band analysis of the sound source.

Still need help with this? Then Essel Acoustics has the skills, experience and qualifications to carry out a noise risk assessment which will include recommending the appropriate hearing protection for staff working in your environment, to fulfil regulatory requirements.

Click here to download a free guide in how to conduct a competent noise risk assessment (which also includes an article on hearing protector overprotection).

£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 by carrying out a competent risk assessment?

There are further points that must be taken into consideration when conducting a suitable and sufficient risk assessment, and these are shown in the FREE guide “A guide to conducting a Hand Arm Vibration Risk Assessment”.

Click here to download your free copy of the guide.

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

Essel Acoustics SatishSatish Lakhiani MSc, MIOA
Essel Acoustics Ltd
Phone: 07710 356663

How hearing protector overprotection could be hazardous in your workplace

You have a situation where you believe employees are exposed to high noise levels, and without carrying out a proper noise risk assessment (if you do carry one out), to be extra cautious you go in overkill mode and issue staff with hearing protectors that provide a higher than necessary level of attenuation. Job done, you reckon.

Beware of what lurks! It might surprise you to realise that you may be overprotecting staff where the noise levels at the ear are suppressed to such an extent that it results in an inability to communicate between co-workers.

There is also the risk of warning signals (i.e. emergency sirens, vehicular alarms and even speech) not being audible enough which could compromise safety possibly endangering life and limb. With overprotection comes a sense of isolation, and workers are tempted to remove their hearing protection or wear them incorrectly thus making them vulnerable to the loud sounds which they were exposed to in the first place, risking hearing damage. So, in effect you are back to ‘square one.’

HSE recommends that with the wearing of hearing protectors, to avoid overprotection the noise level at the ear should not be less than 70 dBA. An ideal choice of hearing protector is one that reduces noise levels to between 70 dBA and 80 dBA at the ear.

Click here to receive your FREE guide in how overprotection may be recognised in your workplace and also what constitutes a good noise risk assessment.

The Assumed Protection Value (APV) – What is it

The Assumed Protection Value (APV) – What is it?

The Assumed Protection Value of a hearing protector – what does it mean, how is it derived, and how does it relate to ‘real’ world conditions?

You may have seen the Assumed Protection Value (APV) printed on the packaging of hearing protectors and probably thought “what does this actually mean?”

The APV data is typically represented as shown in the table below:

Frequency (Hz) 63 125 250 500 1k 2k 4k 8k
Mean attenuation (dB) 14.1 11.6 18.7 27.5 32.9 33.6 36.1 35.8
Standard deviation (dB) 4.0 4.3 3.6 2.5 2.7 3.4 3.0 3.8
APV (dB) 10.1 7.3 15.1 25.0 30.2 30.2 33.1 32.0

The APV values are determined from tests run in a laboratory environment and assumes the minimum attenuation protection that is provided by a hearing protector, in each of the octave frequency bands, for a percentage of wearers. It is these values that are used to calculate the resultant noise levels at the ear with the hearing protector in place, i.e:

Noise level external to hearing protector (dB) – APV (dB) = Resultant noise level (dB) at the ear [for each of the octave frequency bands].

Laboratory testing and derivation of the APV

The APV is derived from the mean attenuation obtained of a hearing protector tested under controlled conditions in a certified laboratory. The test, in accordance with an EN352 standard, follows a subjective based method where the hearing threshold of subjects are measured with and without the hearing protection in place. The noise attenuation is simply the difference between these two measurements.

Test conditions include trained and motivated wearers (receiving supervision, if required) fitting the hearing protection in accordance with the manufacturer’s instructions. This test method provides the best assurance that attenuation data obtained will be repeatable.

The test data is collected across a combination of a specified number of wearers and hearing protectors, and by processing this data, the mean value of the attenuation and the standard deviation (effectively, the spread of the data) may be calculated at each of the frequency bands in the above table for the hearing protector type under test. By definition, we have:

APV (dB) = mean attenuation (dB) – p x standard deviation (dB)

where p is a whole number.

For p = 1 (as it is the case in the above table), this implies statistically that 84% of the population (if tested under laboratory conditions) will be assumed to achieve a minimum attenuation which is given by the published APV. By implication, 16% of wearers will be predicted to under achieve the APV. An important point of note is that 100% of the population will NOT achieve the APV.

The statistical spread of test results in the laboratory are down to, amongst other things, anthropometric differences in head shapes between the test subjects and any manufacturer’s tolerances across the build of the hearing protectors tested.

APV and the ‘real’ world

In the ‘real’ world, however, user conditions are highly uncontrolled compared to a laboratory type environment, due to factors such as incorrect fitting, poor maintenance, the wearing of spectacles and jewellery, plus interference by other personal protective equipment. For these reasons it’s highly likely that the manufacturers’ specified APV performance will suffer some degree of degradation. The HSE recommends that a ‘derating’ factor of 4dB be applied to your calculations (i.e. add 4dB) when predicting the noise level at the ear with the hearing protector in place.

Although it is highly unlikely that the APV performance of a hearing protector can be replicated in the ‘real’ world, with the provision of instruction and training (which is a legal requirement in high risk noisy areas), staff can be taught how to properly wear, maintain and look after hearing protection. The outcome would more than likely maximise the effectiveness of the hearing protection and therefore minimise the chances of noise induced hearing damage.

Confused? Then leave it to us. Essel Acoustics has the skills, experience and qualifications to correctly prescribe appropriate hearing protection and provide training in noise awareness and the correct use of hearing protection at operator and supervisor/manager level.

Click here to receive a free guide in what constitutes a good noise risk assessment. This guide also includes an article on hearing protector overprotection.