The use of power tools, such as table saws, drill presses, and miter saws, is becoming more common in science and STEM laboratories. All power tools have special mechanical and non-mechanical safety hazards that can result in injuries, including abrasions, burns, and fractures. This blog post describes machine-guarding safety protocols that schools need to develop to minimize such safety hazards.

Why machine guards matter

Machine guards are fixed, interlocked, or adjustable physical barriers critical to protecting their operators and those working in the surrounding area from hazards. According to the Occupational Safety and Health Administration (OSHA), machine guarding prevents such safety hazards as rotating parts, flying chips, and sparks.

Types of hazards

Machine operators should be mindful of the following hazards before using a machine or power tool.

• Operation points are locations where the machine bends, bores, cuts, or shapes the stock being fed through the machine.

• Hazardous movements are machine parts with rotating, reciprocating (up-down motions), and transverse motions (materials moving in a continuous line).

• Pinch/shear points are parts of a machine where a body part or clothing could be caught between a moving machine part and a stationary object such as a belt, cam, connecting rods, or other source of energy transmission.

• Non-mechanical hazards include chips, flying splinters, splashes, or sparks that are created while the machine is operating.

Safety rules for machine guards

The following list by North Carolina State University’s Department of Environmental Health Safety offers simple tips to follow when using machines and machine guards.

1. Be sure that moving mechanisms are clear of people and objects.

2. Be sure that workers are not wearing any jewelry or loose clothing that could get snagged in the machine.

3. Keep an eye on overheard moving parts, like pulleys, for potential hazards.

4. Check that guards are in place at all points where you could contact moving parts before turning the machine on.

5. Understand how to turn power on and off if you should have to do so quickly.

6. Read the manufacturer’s instructions on how to operate the machine safely and correctly.

7. Feed material into the machine with push sticks, not your hands.

8. Take it easy. Rushing through a job is one of the major causes of accidents.

9. Make sure maintenance is performed when required. If you think your equipment might have missed its scheduled maintenance let your supervisor know.

10. Use lockout/tagout procedures when a machine needs repair or maintenance. Turn the machine and the power to the machine off and tag it so that no one tries to use it. (This prevents the release of hazardous energy while employees perform servicing and maintenance.)

In addition, machine guards must be secure and tamper-proof so that no one can bypass or remove them. A guard that interferes with the operation in performing the job might be blocked or removed, but this is too dangerous to do. Guards need to be properly used to not only keep workers safe but to perform the job. Guards may need to oiled or greased occasionally to remain functional, but the guard should never be removed because doing so may cause the guard to not function properly or present a sharp hazard. Finally, a guard should never obstruct an operator’s view.

Conclusion

OSHA’s major goal for workers using power tools is to guard all machinery and equipment to eliminate a number of hazards. Always make sure safety guards are in place and that they are working properly, clean, and inspected before use.

Submit questions regarding safety in K–12 to Ken Roy at safesci@sbcglobal.net or leave him a comment below. Follow Ken Roy on Twitter: @drroysafersci.

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