The law lays down action values and limit values for exposure to vibration based on an eight-hour reference period. Separate exposure action values and limit values are given for daily hand-arm vibration and whole-body vibration. Vibration exposure in excess of the action value can have health implications. The implications of vibration exposure in excess of the limit value are so grave that the limit value should never be exceeded.

Surfaces can oscillate in three directions: back and forth, side to side and perpendicularly to the surface. The action value and limit value for hand-arm vibration factor in the magnitudes of vibration in each of these axes. The action value and limit value for whole-body vibration only factor in the acceleration value in the highest of the three axes. As side-to-side motion is more dangerous to the spine than up-and-down motion, lateral acceleration values are multiplied by a factor of 1.4.

A worker’s daily vibration exposure (known as “A(8)”) is compared against the action value and limit value, and the result of the comparison determines what, if any, action the employer must take.

Exposure action values and limit values for vibration

Daily exposure A(8)	Exposure action value	Limit value
Hand-arm vibration	2,50 m/s²	5,00 m/s²
Whole-body vibration	0,50 m/s²	1,15 m/s²

 

Employer’s obligations based on the level of exposure

Where daily vibration exposure exceeds the action value, the employer must

• establish and implement a vibration control programme and
• instruct their occupational health care provider to perform regular health examinations on exposed employees.

Where daily vibration exposure exceeds the limit value, the employer must

• take immediate action to reduce the exposure to below the limit value
• identify the reasons why overexposure has occurred, and
• amend the protection and prevention measures in order to avoid any recurrence.