Answers to some of your common questions about vibration and HAVS monitoring.
Q. How is vibration measured?
Vibration is measured using an accelerometer, attached to the tool or equipment. This will measure vibration in each of the three axes, and give a tri-axial sum, as well as measuring the duration of use, and therefore the total dose.
Q. What is vibration magnitude and where can I obtain figures?
Vibration magnitude is the level of vibration at the hand position on the tool handle. It is expressed as an acceleration value in metres per second squared (m/s2).
Manufacturers of tools and equipment have a legal duty to provide you with the equipment’s vibration emission value. However, many will be tested and declared under laboratory conditions and therefore underestimate that produced in real use. When contacting suppliers or manufacturers through procurement, you should ask for values that represent real life use in circumstances that the tool will be used. Consider factors such as:
- Type of equipment (pneumatic drill, whacker plate).
- Power source (electric, pneumatic).
- Class of equipment (power rating, operating speed, size or weight).
- Any anti vibration features (suspended handles).
- The task for which the equipment was used when the vibration was measured (e.g. breaking concrete, grinding steel).
- The material being worked.
- Any accessories or inserted tools (type of chisel or grinding disc).
Q. Do we need to continually monitor workers’ exposure to vibration?
There is no legal requirement for continual monitoring and recording of vibration exposure and in theory, you may only need to test your equipment once. If tools are kept in good condition and are well maintained they shouldn’t produce any different levels as time goes on. However, you must decide what an individuals exposure is likely to be as part of a vibration risk assessment. A period of monitoring to understand how long an individuals use of particular tools in a typical day or week may be necessary if it helps you to do your risk assessment. Once you know enough about the work to say what the exposure is likely to be (and whether it is likely to exceed either the Exposure Action or Exposure Limit Value) your focus can shift to investigating, and taking, practical steps to reduce the exposure and the risks.
Q. What about the ‘tool timers’ and ‘vibration meters’ that can be bought, can these be used to monitor exposure?
There is nothing wrong with using these devices, it’s just that there is not generally a need for one to be issued to every individual, or attached to every tool. Continual monitoring and recording of vibration exposure is not a requirement of the regulations, nor does the HSE advise that it is a sensible thing to do on a routine basis. It is worth noting that some devices that are sold as ‘vibration meters’ do not measure the vibration exposure of individual; they may only measure the amount of time that a tool is being used. So similar to a stopwatch (but a bit more expensive).
Q. When does HAVS monitoring need to be carried out?
HAVS monitoring is usually carried out when new equipment is purchased, following equipment repairs, or when new staff start.
Q. How long does it take?
Individual tools will be monitored using a vibration meter for a period of 20 minutes. It is essential to monitor each tool during its normal work routine so if the tool is meant for cutting wood/masonry or metal it will be required to be monitored whilst cutting the appropriate material in order to give real-life results.
Q. Is there HAVS PPE?
Yes, anti-vibration gloves do exist! However, anti-vibration gloves do not assist in controlling exposure. They can assist in keeping hands warm and maintaining circulation. Gloves should not create any additional hazard, for example cause entanglement in machinery.
Q. When is health surveillance required?
Health surveillance is required where individual(s):
- are likely to be regularly exposed above the action value of 2.5 m/s2 A(8), and a daily exposure limit value(ELV) of 5m/s2A(8)
- are likely to be exposed occasionally above the action value and where the risk assessment identifies that the frequency and severity of exposure may pose a risk to health
- have a diagnosis of HAVS (even when exposed below the action value).
Q. What next?
Take positive action to reduce the exposure and the risks e.g. change the work process to avoid the need to use hand tools, modify the work to improve ergonomics, change to better tools with lower vibration and good ergonomic design, maintain and look after the tools and consumables, train your workers. Make sure that the action you take results in real changes; monitor your systems and make sure work instructions are being followed. Don’t forget health surveillance for those at risk, to pick up early signs of ill-health.