Maintain tools so that they are efficient and suitable for their purpose
WITH the advent of pneumatic tools in the mid-eighteenth century, workers began to complain about tingling and loss of sensation in their fingers, as well as hand weakness and white fingers. This condition, known medically as Secondary Raynaud’s syndrome, or hand-arm vibration syndrome (HAVS), or more colloquially as ‘white-finger syndrome’, results from long-term work with vibrating tools. Hand-arm vibration over extended periods can damage the blood vessels and nerves in the upper limbs, sometimes permanently, and it is a risk today in jobs in many industries and occupations, including some work typical of turfcare professionals. The Control of Vibration at Work
Regulations 2005 came into force on the 6th July last year. They set responsibilities on all employers to ensure their staff are protected from the risks of vibration at work. Like other health and safety legislation, the Regulations require employers to identify and assess the risks, take action if necessary, and monitor the effectiveness of the action. Vibration is measured in m/s2
- a unit
of acceleration - and it is averaged across a specified period of time. The exposure action value for an employee working an eight-hour day is 2.5 m/s2
. For shorter
periods the exposure action value is higher. Above the action value, employers must take action to reduce the exposure. The exposure limit value is 5 m/s2
for an eight-hour day, again
increasing for shorter periods. Hand-arm vibration must not exceed the limit value. Table 1 below gives some typical values for power tools (from HSE data). With these values in mind, let’s look at the steps you should take to comply with the Regulations.
Step 1: Begin with a risk assessment. List all the jobs that involve machinery and tools causing hand-arm vibration. Estimate the vibration of each tool from the Table of typical values. You might
Table 1: Typical vibration values Tool
Lowest Typical Highest (m/s2
) (m/s2
Road breakers 5 Angle grinders 4 Chainsaws
-
Brushcutters 2 Sanders
- 20 ) (m/s2
12 20 -
6 4
8 - -
7-10 - )
also approach the manufacturer for estimates or make direct measurements with a meter, although that may not be practicable. Make sure your risk assessment is contained in a document that can be stored, either as a hardcopy or on computer.
Step 2: Calculate the exposure level for your employees, taking account of the time they use each of the tools. You can use the HSE calculator to do this (see the reference at the end of the article). The calculator takes account of the time an employee spends using each tool per day (sometimes called the ‘trigger time’). An alternative, less accurate but swifter approach proposed by the HSE is shown in Table 2 below.
Step 3: Once you have an estimate of exposure levels, you can check whether they exceed the exposure action level or the exposure limit value. If they do, you must take measures to reduce exposure by modifying the task or equipment. Some of the options open to you are listed below.
• Use appropriate equipment to minimise the time employees are exposed to vibration. Using under- powered tools, for example, will lengthen the task time and increase exposure to vibration.
• Avoid handheld power tools. In some cases you might be able to do the job with tractor-mounted tools.
• Choose your tools carefully. You could consider selecting low vibration tools at the time of purchase or hire, perhaps asking manufacturers for typical values to assist in your choice. Your employees might be a good source of advice on which tools have low vibration and which are best for the job in hand.
• Maintain tools so that they are efficient
and suitable for their purpose. Timely and appropriate maintenance keeps tools running smoothly and reduces vibration.
• Use a tool’s in-built vibration protection when available.
•Limit employees’ exposure by scheduling their tasks appropriately. For example, you might share a task between a number of people, reducing the periods and overall duration of exposure for each person.
• Provide suitable clothing to keep employees warm and dry. But do not rely on gloves to protect against vibration.
YOU should also provide training to your employees when the exposure action value is exceeded. Not necessarily intensive, the training should at least include a description of the health risks of vibration, sources of vibration, the action values, methods of reducing risk, and the need to report any ill-effects of using vibrating tools. You will need to keep track of any changes to working procedures that
Vibration (m/s2)3 4
Table 2: Estimating vibration exposure 5
6 7 10 12 15
Points per hour 20 30 50 70 100 200 300 450 Calculate the total number of points per day: 100 points per day = exposure action value 400 points per day = exposure limit value
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