What part of the hand do you assess vibration?

• How do I get started?
• Estimating employees' exposure
• Duties of manufacturers and supplier

The aim of the risk assessment is to help you decide what you need to do to ensure the health and safety of your employees who are exposed to vibration.

Your risk assessment should:

• Identify where there might be a risk from vibration and who is likely to be affected;
• Contain a reasonable estimate of your employees' exposures, and;
• Identify what you need to do to comply with the law eg whether vibration control measures are needed, and, if so, where and what type; and
• Identify any employees who need to be provided with health surveillance and whether any are at particular risk.

You must record the findings of your risk assessment. You need to record in an action plan anything you identify as being necessary to comply with the law, setting out what you have done and what you are going to do, with a timetable and saying who will be responsible for the work.

You will need to review your risk assessment if circumstances in your workplace change and affect exposures. Also review it regularly to make sure that you continue to do all that is reasonably practicable to control the vibration risks. Even if it appears that nothing has changed, you should not leave it for more than about two years without checking whether a review is needed.

How do I get started?

If you answered 'yes' to any of the questions in the section 'Do you have a vibration problem?' you will need to assess the risks to decide whether any further action is needed, and plan how you will do it.

To carry out your risk assessment you will need to identify whether there is likely to be a significant risk from hand-arm vibration. You should:

• Find out from your employees and their supervisors which, if any, processes involve regular exposure to vibration (eg processes using the equipment listed in 'Which jobs and tools produce a risk?' or other vibrating equipment);
• See whether there are any warnings of vibration risks in equipment handbooks;
• Ask employees if they have any of the HAVS symptoms described in these web pages and whether the equipment being used produces high levels of vibration or uncomfortable strains on hands and arms.

Consultation

It is important during this whole process to discuss hand-arm vibration with your supervisors, employees and the trade union safety representative or employee representative. You will need to develop and agree a policy for managing vibration risks which will provide reassurance to your employees about their job security and to explain why co-operating with your risk control measures and health surveillance programme will be in their best interests.

Assess who is at risk

If there is likely to be a risk you need to assess who is at risk and to what degree. The risk assessment needs to enable you to decide whether your employees' exposures are likely to be above the EAV or ELV and to identify which work activities you need to control.

Competence

You could do the risk assessment yourself or appoint a competent person to do it for you. The person who does the risk assessment should have read and understood these pages, have a good knowledge of the work processes used in your business and be able to collect and understand relevant information. They should also be able to develop a plan of action based on their findings and ensure it is introduced and effective. They will need to:

• Make a list of equipment that may cause vibration, and what sort of work it is used for;
• Collect information about the equipment from equipment handbooks (make, model, power, vibration risks, vibration information etc);
• Make a list of employees who use the vibrating equipment and which jobs they do;
• Note as accurately as possible how long employees' hands are actually in contact with the equipment while it is vibrating – in some cases this 'trigger time' may only be a few minutes in several hours of work with the equipment;
• Ask employees which equipment seems to have high vibration and about any other problems they may have in using it, eg its weight, awkward postures needed to use the tool, difficulty in holding and operating it;
• Record the relevant information they have collected and their assessment of who is likely to be at risk.

How should I use this information?

Group your work activities according to whether they are high, medium or low risk. Plan your action to control risks for the employees at greatest risk first. Your rough groupings could be based on the following:

High risk (above the ELV)

Employees who regularly operate:

• Hammer action tools for more than about one hour per day; or
• Some rotary and other action tools for more than about four hours per day.

Employees in this group are likely to be above the exposure limit value set out in the Regulations. The limit value could be exceeded in a much shorter time in some cases, especially where the tools are not the most suitable for the job.

Medium risk (above the EAV)

Employees who regularly operate:

• Hammer action tools for more than about 15 minutes per day; or
• Some rotary and other action tools for more than about one hour per day.

Employees in this group are likely to be exposed above the exposure action value set out in the Regulations.

Do I need to measure my employees' exposure to vibration?

The rough groupings described above should be enough for you to do a basic risk assessment which will enable you to decide whether exposures are likely to exceed the exposure action value and exposure limit value and to allow you to plan and prioritise your control actions effectively. For further information see 'Control the risks'.

Alternatively, you may choose either to use available vibration data or to have measurements made to estimate exposures if you want to be more certain of whether the risk is high, medium or low. A more detailed exposure assessment may help you:

• Decide which control actions might be most effective and practicable in reducing vibration exposure;
• Be more certain whether exposures are likely to exceed the action or limit values;
• Check whether your controls are effective.

 If you decide to do this, read 'Estimating exposure'.

Estimating Exposure

You may be able to get suitable vibration data from the equipment handbook, or from the equipment supplier. See Table 1 for examples of vibration levels HSE has measured on equipment in use. There are also some databases on the internet which may have suitable vibration data.

If you plan to use the manufacturer's vibration data you should check that it represents the way you use the equipment (see 'Duties of manufacturers and suppliers') since some data may underestimate workplace vibration levels substantially. Ask the manufacturer for an indication of the likely vibration emission of the tool when your employees are using it. If you are able to get vibration data from the manufacturer which is for common tools reasonably representative of the way you use the equipment, it should be suitable for you to use in estimating your employees' exposure.

Table 1 Some typical vibration levels for common tools

You also need to check, by observing them, how long employees are actually exposed to the vibration (ie the total daily 'trigger time' with the equipment operating and in contact with the employee's hand(s)). Employees are unlikely to be able to provide this information very accurately themselves. You could observe and measure the trigger time over, for example, half an hour and then use the result to estimate the trigger time for the full shift. Alternatively, where the work task is repetitive, eg drilling large numbers of holes in masonry, you could measure the trigger time when drilling several holes and multiply the average by the number of holes typically drilled in a shift.

If the employee is exposed to vibration from more than one tool or work process during a typical day, you will need to collect information on likely vibration level and 'trigger time' for each one.

Once you have collected relevant vibration data and exposure times you will need to use an exposure calculator to assess each employee's daily exposure

Alternatively, you can use the simple 'exposure points' system in Table 2 to estimate the daily exposure.

Table 2 Simple 'exposure points' system

Multiply the points assigned to the tool vibration by the number of hours of daily 'trigger time' for the tool(s) and then compare the total with the exposure action value (EAV) and exposure limit value (ELV) points.

100 points per day = exposure action value (EAV)
400 points per day = exposure limit value (ELV)

Workplace vibration measurements

If you want to obtain vibration measurements for your own tools you will need to arrange for a competent person to carry out measurements for you using specialised equipment. Measurement results can be highly variable, depending on many factors, including the operator's technique, the condition of the work equipment, the material being processed and the measurement method. The competence and experience of the person who makes the measurements is important so that they can recognise and take account of these uncertainties in producing representative vibration data.

Duties of manufacturers and supplier

How can tool and machine manufacturers and suppliers help?

Tool and machine manufacturers are obliged by the Supply of Machinery (Safety) Regulations 2008 (as amended) to design equipment which will reduce vibration risks to as low a level as possible, making use of the latest technology. The equipment should be CE-marked to show that it complies with these requirements, and health and safety information should be provided in the user instructions. This should include:

• Warnings about any vibration-related risk from using the equipment;
• Information on safe use and, where necessary, training requirements;
• Information on how to maintain the equipment;
• A statement of the vibration emission (or a statement that the vibration test has produced a vibration emission of less than 2.5 m/s2) together with information on the test method used.

For most types of tool, manufacturers use internationally agreed test methods for vibration testing. These allow you to compare the vibration performance of different brands and models of the same type of tool. Unfortunately, many of these test methods do not represent the way tools perform at work and vibration levels in the workplace may be much higher than those in this type of 'laboratory' test.
In some industries, employers' organisations, equipment manufacturers and hire companies have adopted colour-coding systems to mark tools to show which are high, medium and low risk. These 'traffic light' systems are intended to help users manage the use of the tools to control risks from vibration.

In most cases the Supply of Machinery (Safety) Regulations 2008 will not apply to those supplying or hiring out work equipment, but suppliers and equipment hirers will be subject to Section 6 of the Health and Safety at Work etc Act 1974. Equipment should be provided with adequate safety information, including on vibration, normally in the form of the manufacturer's user instructions.

What part of the hand is used to assess vibrations?

How do you assess vibration?

How do you measure hand

What is vibration white finger or hand/arm vibration HAVS?