Controlling Hand-Arm-Vibrations

Hand-Arm Vibration (HAV) is defined as the transfer of vibration from a tool to a worker’s hand and arm. Hand-arm vibration is caused by the use of vibrating hand-held tools, such as pneumatic jack hammers, drills, gas powered chain saws, and electrical tools such as grinders. The nature of these tools involves vibration (a rapid back and forth type of motion) which is transmitted from the tool to the hands and arms of the person holding the tool. The vibration is typically measured on the handle of tool, while in the grasp of the worker, and the amount of HAV is a function of the acceleration levels transferred to the worker.

Vibration restricts the blood supply to the hands and fingers. Signs and symptoms of vibration-induced injury, such as Reynaud’s phenomenon, start with occasional numbness or loss of color in the fingertips. This progresses to more frequent and persistent symptoms affecting a larger area of the fingers and resulting in reduction in feeling and manual dexterity.

This handout provides recommendations for managers and workers to minimize the injury risk from HAV.

Management

Train workers to recognize the warning signs of HAV.

Medically monitor workers who routinely use products associated with HAV.

Institute health care management practices ensuring early detection of hand/arm vibration disorders.

Purchase new vibration-reduced tools.

Inspect and service tools at regular intervals in accordance with manufacturer instructions.

Repair or replace tools producing high vibration levels due to wear and tear.

Workers

Wear protective clothing, such as multiple layers of gloves or anti-vibration gloves, to reduce the transmission of vibration energy to the hands and to protect the hands against exposure to cold.

In cold weather, dress adequately to keep the whole body warm since a low body temperature can make you more susceptible to HAV.

Take a 10-minute break after each hour of continuously using a vibrating tool.

Let the tool do the work by grasping it as lightly as possible, consistent with safe work practice.

Keep chisels and chainsaws sharp to reduce vibration. Using new grinder wheels will also reduce vibration.

Operate the tool at the minimum speed (and impact force) to reduce vibration exposure.

Substitute a manual tool or other process where practical.

COPYRIGHT ©2006, ISO Services Properties, Inc.