Week 1- Machine Guarding Safety
Guarding serves to protect employees from hazards created by rotating parts, pinch points, points of operation, and from flying particles and sparks created by the operation of machines. Unintentional contact with moving parts can cause cuts, amputations, burns, and even death.
According to the Occupational Health and Safety Administration (OSHA), workers who operate and maintain machinery suffer approximately 18,000 amputations, lacerations, crushing injuries, abrasions, and over 800 deaths per year.
General Guard Requirements
OSHA requires any machine part that could cause injury to be safeguarded. Some examples of where guards are required include moving belts, chains, drums, gears, shafts, pulleys, spindles, sprockets, and flywheels. Safeguards must prevent contact with the hazard, should not be easily removed or defeated, and must not create any additional hazards, such as pinch points.
Types of Guards
Fixed Guards – Guards that are permanently fixed to the machine. Adjusting or servicing of the guard requires the machine to be disassembled. An example is a fan blade or belt and pulley system.
Self-Adjusting Guards – Guards that are designed to automatically adjust to the size of material being fed into the machine. While not in use, the guard returns to a fully closed position. An example is use on a radial arm saw or jointer.
Adjustable Guards – These guards are similar to self-adjusting guards, but these must be manually set. This type of guard is useful when handling materials that vary in size. When improperly adjusted, guards can fail to prevent contact with moving parts. An example is what is used on a bandsaw.
Interlocking Guards – In order for the related machinery to turn on, the interlocking guard must be engaged. When the guard is disengaged or not in place, the machinery will shut off. An example is the guards used on a mixer or picker.
Summary
Machine guards should never be modified or removed. Prior to operating machinery, guards should be inspected. Operators should never try to defeat guards such as two-handed control devices through the use of a “cheater bar” or other means. Prior to adjusting or servicing any machine guard, all applicable lockout/tagout (LOTO) procedures should be followed. Only authorized personnel should conduct servicing of guards. Failure to follow safe work practices can result in serious injury, amputation, or death.
Week 2- Extension Cord Safety
Overloading an Extension Cord – Extension cords are designed for a certain amount of electricity to be drawn through the cord (usually expressed as “amps”, or amperage). Overloading an extension cord by using it to power equipment that draws too much current can cause the cord to over-heat and short out. So check your extension cord to determine the maximum amperage for which the cord is rated, and compare that to the amperage drawn by the equipment attached to that cord so you can avoid overload situations. It may be necessary to get a heavier cord to handle the load.
Using Extension Cords in Place of Permanent Wiring – Extension cords are intended to be used as a temporary source of power (usually considered to be 30 days or less). But in some situations, you will find extension cord that have been strung through rafters, attached along a wall, or run through a chase-way or trough on a long-term basis to provide a permanent supply of power to a piece of equipment or machinery. This is not allowed!
Running Extension Cords Through Windows, Doorways, and Other Openings – If the window or door gets closed on an extension cord, or if the cord gets moved back and forth repeatedly, it can become pinched or weakened and break the insulation on the wiring. This condition could then expose energized electrical conductors inside the cord that could short out, or even electrocute a person if they make contact with the damaged area.
Using Extension Cords Rated for Indoor Use Outdoors – Extension cords intended for indoor use only are not designed to stand up to extreme outdoor conditions, such as cold, ice, wetness, or excessive heat. These conditions can weaken the cord and cause it to deteriorate, which could lead to excessive heat build-up and an overload situation. Check the tag on the cord or the packaging it came in to determine if it is, or is not, designated for outdoor use.
Leaving Unsafe Extension Cords in service – If you find an extension cord that is being used improperly, or is damaged, please notify your supervisor immediately, or unplug the cord and turn it in to the person(s) responsible for replacement and/or repair (discuss who that is for your workgroup).
DO NOT attempt to repair an extension cord unless you are specifically authorized to do so.
Week 3- Harmful Dust and Fumes
On Construction sites we can come across various types of dust, and fumes. It is important while working on these sites we are able to address and observe when things concerns, we advise the General Contractor. Below lets take a look at a few items;
Some Sources Of Harmful Dust And Fumes
• Cutting, sanding, and grinding of some materials will create harmful dust.
• Welding and gas cutting of metals can create harmful fumes.
• Heating metals such as lead will create harmful fumes.
• Work with old lead can expose you to lead oxide dust (white, powder deposits), which are also harmful.
• Burning off old lead-based paints can also create harmful fumes.
• Stripping out or other work involving fibrous insulation (such as asbestos or fiberglass insulation) can release harmful dust into the air.
Some Health Risks from Breathing In Dust Or Fumes
• Silica dust from cutting or scabbling concrete can cause lung disease.
• Dust from cutting or sanding hardwood can cause nasal cancer.
• Asbestos dust can cause cancer of the lungs or lining of the chest cavity.
• Welding fumes can result in ‘metal fume fever’, which has flu like symptoms.
Precautions
• Where it is possible, the job should be planned to eliminate harmful dust and fumes.
• If elimination is not possible, harmful dust and fumes must be controlled so that they are not breathed in by anyone.
• Some tools and plant are fitted with dust extraction and collection devices – if these are available, use them.
• If your employer has provided portable extraction equipment, use it.
• It may be necessary for you to wear RPE to protect yourself from the effects of dust or fumes – make sure you know how to use it properly.
• Consider the effects that your work may be having on other people.
Week 4- Vibration
Effects Of Vibration
• Depending upon the work situation, vibration can be whole body vibration or, more commonly, hand arm vibration.
• The first signs of a problem may only be tingling in the affected fingers.
• Exposure to vibration can lead to irritation, fatigue and loss of concentration.
• The above effects are likely to affect a person’s attention to safety and therefore, increase the likelihood of an accident occurring.
• In the longer term, damage may occur to blood vessels, nerves, muscles tendons and body organs.
• Excessive hand arm vibration can lead to ‘Vibration White Finger’, resulting in damaged blood vessels, circulatory problems, pain and possible gangrene.
The Sources Of Vibration
• A common cause of hand arm vibration is the prolonged use of rotating hand tools used for cutting and grinding.
• Percussive hand tools used for riveting, chipping, hammering, drilling etc. are also sources of vibration.
The use of chainsaws is also another source of hand arm vibration.
• Advances in technology are leading to newer tools being equipped or manufactured with vibration absorbing features.
• If available, select tools with vibration absorbing features for your work.
• When using a tool which causes vibration, break the job up with other work activities.
• If you think you are suffering ill effects from vibration, cease the activity, speak to your supervisor and if necessary, seek medical advice.
REMEMBER: THE LONG TERM EFFECTS OF EXPOSURE TO VIBRATION CAN BE PERMANENT AND DISABLING. DO NOT LET IT HAPPEN TO YOU