Portable Power Tools
Table of Contents
Information on this page is drawn from "Installation and Repair: Using Tools" published by OSHA
Potential Hazards:
- Some portable power tools, such as pipe threaders (Figure 5), may be heavy or require extreme effort to counteract torque forces. Sustained use of these tools puts stress on the back, hands, arms, and shoulders.
Figure 5
A heavy pipe threader.
- Tools such as jack hammers or large saws that transmit vibration may cause hand-arm vibration syndrome (HAVS). Early signs of HAVS are feelings of numbness or tingling in the fingers, hands, or arms, or numbness and whiteness in the tips of fingers when exposed to cold.
- When using tools employees may assume awkward postures including bending, stooping or extended reaching. Awkward postures maintained for long periods of time may cause fatigue, discomfort and pain, especially when heavy tools are used.
- Improper orientation of tool handles may cause awkward position of the hand, wrist, or arm and increase force requirements of the task.
- Repeatedly using a single finger to activate triggers on power tools may cause overuse of tendons and muscles leading to irritation, swelling, pain and eventually immobility.
Possible Solutions
- Use tools with a proper handle orientation that allows neutral wrist position. Generally, use tools with a pistol grip for vertical surfaces and an in-line grip for horizontal surfaces.
- Use torque bars (Figure 6) on tools such as drills or pipe threaders to minimize the exertion required to control the tool.
Figure 6
Drill with torque bar.
- Use trigger-levers on power tools. These have a longer trigger to accommodate three fingers, rather than those with single finger trigger action.
- Maintain equipment and tools in proper working order. Unbalanced rotating parts or poorly sharpened cutting tools may create excessive vibration and increase force requirements when in use.
- Support the weight of heavy tools (Figure 7) by using overhead or under-tool supports.
Figure 7
Vice mounted on a three-legged stand.
- Avoid older power tools that were not designed with ergonomics in mind and may vibrate excessively. Consider reduced-vibration tools when making new tool selection.
- Wear proper anti-vibration gloves when using power tools and use only as much finger force as necessary to provide proper control of the tool.
- Learn proper tool usage and safety practices. Employees should allow the tool or machine to do the work and should arrange the work so that they can stand upright and use the tool with the elbows close to the body.
- Keep hands warm and dry.
- Use platform ladders, regular ladders or lifts to reach higher work areas so that arms may be kept closer to the body. The arms may then safely support tools when in the power zone.
- Wear kneepads when kneeling is required.
- To reduce crouching and kneeling, sit on a stool while working on lower areas.
- Minimize the time of continuous use when operating a vibrating tool. Appropriate operating times will vary depend on the magnitude of vibration, however limiting sessions to 10 to 15 minute of continuous use with no more than 2 hours of total operating time per day is generally recognized as a prudent work/rest schedule. Other means of dampening or reducing vibration should still be observed even during shortened sessions.
o Criteria for a Recommended Standard: Occupational Exposure to Hand-Arm Vibration. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 89-106, (1989, September).
- Keep cutting surfaces of tools sharp and lubricated.
