1. Machine Guarding— The Case of the Inadequate Guard
P O W E R P O I N T ® T R A I N I N G
Background for the Trainer:
This case and its training message primarily have to do with machine guarding. Therefore, it is most appropriate for every employee who works with or near machinery. This session is probably not appropriate for workers who are never exposed to machinery.
This training session presents a case study of an actual accident inspected and documented by the Occupational Safety and Health Administration (OSHA). The case presented in this training session is:
Accident:
Report ID:
Inspection:
You may choose to present this training information in a lecture format, or make the training presentation interactive by engaging your class in discussions that will help them identify facts of the case, potential causes of the accident, and future accident prevention measures. In either case, students will benefit by learning from a real-life scenario.
Before beginning your training session, print and make copies of the one-page Case Study Student Handout, which is provided on the disc. The Case Study Student Handout can be used as a worksheet during the training session or as a take-away reminder once the training session is complete.
Also, print and make copies of the Case Study Quiz, which is provided on the disc as a fully customizable Word document. The students can take the quiz at the end of the training session in order to help reinforce the information presented. Note that the same quiz is included at the end of this PowerPoint presentation as actual slides to review in class.
Consider taking pictures of machine guarding in your workplace. You can add these pictures to the presentation by inserting them into existing slides or creating new slides.
Make sure the trainees understand the message as you go along. Ask questions periodically to test their understanding.
Speaker’s Notes:
Welcome everyone. Today we will review a case study of an actual accident investigated by the Occupational Safety and Health Administration (OSHA). This is an actual tragic workplace accident that had real-life implications for the worker, the worker’s family, co-workers, and the employer.
The purpose of this training session is to teach and reinforce the importance of adequate machine guarding in our workplace in order to prevent tragic accidents. In particular, it deals with how to inspect the guarding on the machines and equipment in your work area so that you can report inadequate or damaged machine guarding to your employer. The intention is to learn from the accident and take steps to prevent a similar accident from occurring at our facility.
Machine Guarding—
The Case of the Inadequate Guard
©2003

2. Machine Hazards Point of operation: Mechanical motion: Cutting
Punching
Shearing
Bending
Mechanical motion:
Reciprocating
Transverse
Rotating
Nip points
Speaker’s Notes:
The point of operation is the area on the machine where work such as cutting, drilling, shaping, and forming is performed on the material. The point of operation is the most hazardous area on most machinery.
Cutting is one of the primary actions conducted by machinery at the point of operation. Examples of cutting equipment include band saws, circular saws, drills, lathes, and mills.
Punching occurs when a powered ram is used to blank, draw, or stamp material such as metal. An example of machinery with a punching action includes power presses.
Shearing occurs when a powered knife or slide is utilized to cut sheet metal or other materials. Shears can be mechanical, hydraulic, or pneumatic.
Bending involves a powered slide that is used to draw or stamp materials such as sheet metal. The operator is exposed to the point of operation when inserting, holding, and ejecting the material.
Almost every machine has moving components that, if not properly guarded, will injure a worker who is in the area of motion. Employers and employees need to recognize the various types of machinery motion so that steps can be taken to protect people from those hazards.
Reciprocating motions include the back and forth or up and down motion of machine components. Many machines have some form of reciprocating motion, which may be slow and easy to avoid or it might be fast and sudden.
The transverse motion of machinery is motion in a straight or continuous line. This motion creates a hazard because the worker may be dragged into a pinch point or shear point. An example includes the motion of a powered belt, which could pull fingers, clothing, or hair into the pinch point.
Almost every machine has some form of rotating motion, and every form of rotation can be dangerous and cause severe injuries. Even slowly rotating smooth shafts can grab clothing or hair. Even more danger occurs when the rotating shaft has exposed keys, set screws, bolts, nicks, or even spokes, which can grab loose clothing, long hair, or jewelry, and pull a worker’s body into the rotating equipment.
A nip point is created when parts with parallel axes rotate in opposite directions. Examples include rollers and sprockets. Another nip point is created between a rotating component and a tangentially moving part. For example, a nip point is created between a rotating shaft and a tangentially moving conveyor belt.

3. Take a Look at the Facts
Employee is sweeping ground wheat from around machinery
Work rules did not address cleaning around operating machinery
Background for the Trainer:
Training Option: Pass out the Case Study Student Handout. You may have the students read the accident description to themselves before discussing it in the class, or you may use the bullet points on the slide and the speaker’s notes below to describe the accident.
Speaker’s Notes:
An employee is sweeping a large accumulation of ground wheat (break fines) from around floor mill roll stand machinery.
Written work rules did not specifically address an acceptable method of cleaning around machinery in operation.

4. Take a Look at the Facts (cont.)
4-inch gap between guard and the machine body
She reaches under a belt and pulley guard with a hand brush
No guard under the belt and pulley assembly
Speaker’s Notes:
The guard on the belt and pulley assembly was inadequate; there was a 4-inch gap between the guard and the mill machine body.
She reaches under a belt and pulley guard with a hand brush in her left hand.
There was no guarding around the belt and pulley assembly, which allowed the employee access to the hazard.
©2003 Business & Legal Reports, Inc.

5. Take a Look at the Facts (cont.)
Left glove is caught by in-running belt, and hand is pulled into motor pulley
Employee loses middle and index fingers and suffers two compound fractures to left arm
Speaker’s Notes:
Her glove is caught by the in-running portion of the notched flat belt, which is approximately 16 inches from the floor.
Her left hand is pulled into the 20-horsepower motor pulley, which operates at approximately 1,600 rpm. She runs to another employee who then provides first aid and summons help.
The employee suffers two compound fractures to her left arm.
She also suffers damage to the hand, including the complete loss of the middle and index fingers.
©2003 Business & Legal Reports, Inc.

6. What Do You Think Went Wrong?
Why did the employee reach under the guard?
Was the employee aware of the hazards?
Did the employee see the guard and assume there was no hazard?
Did the employee’s glove play a role?
Should workers clean under operating machinery?
Who should inspect machine guarding?
Background for the Trainer:
Use the questions on this slide to elicit discussion.
Training options: After reviewing this slide and the accident description, give the class 5–10 minutes to discuss the accident description in small groups, or ask the students to try to determine some of the facts, potential causes, and possible preventive measures. In either case, use the Case Study Student Handout as a way to encourage discussion as you go through this presentation.
Speaker’s Notes:
Let’s take a few minutes and, using the Case Study Student Handout, work in groups to try to determine the facts of the accident, potential causes of the accident, and possible preventive measures. Then we will review the case study together in class.
Consider some of the questions on this slide when discussing the case study in your groups.

7. Let’s Review the Causes
Employee reached under guard
Employee did not inspect guard
Guard did not completely cover the hazard
Employee attempted to clean under operating machinery
Lack of work rules and training
Background for the Trainer:
Try to get the trainees to put themselves in the place of the person in the case study. What would they have done in this case? Point out how a near miss can turn into a catastrophe in the presence of emergencies. In this case, the employee reached under a guard and got her hand caught in a belt and pulley assembly.
Speaker’s Notes:
By reaching under the guard and under the machine, the employee put herself in danger. If she was not aware of the hazards associated with the machinery, she should not have reached under the machine. Employees should always stay away from machines unless they have been trained and made aware of the potential hazards of the machines. Even if you are only cleaning around the machine, it is important to stay away unless you have been trained on the hazards and danger zones of the machine.
The employee did not inspect the machine’s guard to ensure it was adequate such that it would prevent her from touching or being caught in the machine’s motion. All machine operators should inspect the guarding on their equipment daily to make sure it has not been removed or damaged since they last operated it. Inadequate guarding should be reported immediately for repair.
The guard did not completely cover the hazard. According to OSHA’s inspection, there was a 4-inch gap between the guard and the machine body, which means a worker could have reached into the gap from the top or the sides. Also, the bottom of the belt and pulley, which was 16 inches from the floor, was not guarded at all.
The employee attempted to clean under the machine while it was still in operation. If the employee had waited for the machine to stop operation, then applied lockout and tagout to the machine before cleaning under it, she would not have been injured.
According to the OSHA inspection, there appears to be a lack of written work rules regarding cleaning around machinery—especially when it is in operation. Also, there appears to be a lack of training because the worker did seem to be aware of machine hazards, the importance of guard inspections, or lockout and tagout practices.
Can you think of any other causes that may have contributed to this accident?

8. Let’s Talk About Guard Types
Fixed guards
Interlocked guards
Adjustable guards
Self-adjusting guards
Speaker’s Notes:
Fixed guards are probably the most common type of guard because of their simplicity and effectiveness. Fixed guards are considered permanent or require quite a bit of work to remove in order to gain access to the hazard they are covering. They can be made from many materials (metal, plastic, screen, bars, etc.). Fixed guards commonly cover belts and pulleys, chains and sprockets, gear systems, etc.
Interlocked guards are designed to be opened to allow the worker access to the hazard zone. However, once the guard is opened, the machine will shut down automatically and effectively eliminate the hazard, usually a point of operation, which was covered by the guard. The machine cannot be restarted until the guard is returned. A downfall of interlocked guards is that employees have often found ways to bypass them by taping limit switches closed such that the guard can be removed, and the machine or equipment continues to run. This results in employees being exposed to the hazard that the guard was supposed to protect them against.
Adjustable guards are useful because they allow the machine to still handle a wide variety of material sizes while still keeping the unused portion of the blade or other point of operation covered by the guard. These guards must be adjusted manually. Examples include band saws on which the guard over the point of operation can be fully opened for large materials and almost completely closed over the blade when cutting thin materials. Adjustable guards rely on the operator to close the guard.
Self-adjusting guards, typically found on saws, are pushed away from the point of operation when the material is fed into the machine and open only enough to allow the material into the cutting zone, thus keeping the remainder of the blade covered in order to protect the operator. Once the material is removed from the point of operation, the self-adjusting blade returns to its original position and completely covers the blade. Self-adjusting blades are most often thought of being on handheld circular saws and table saws.

9. Keys to Adequate Guarding
Prevent bodily contact
Secure guards to machinery
Protect from falling objects
Create no additional hazards
Ensure safe lubrication
Does not interfere with production efforts
Background for the Trainer:
Bring any written procedures your company has for inspecting guards.
Show pictures of adequate guards in your workplace.
Speaker’s Notes:
Guards are required to meet these minimum general requirements.
Preventing bodily contact is the primary purpose of a guard. Guards must prevent machine operators and other workers from making bodily contact with the machine’s dangerous areas such as the point of operation and mechanical motions.
Guards must be secured to the machinery so that they cannot be easily removed by workers or tampered with in other ways that make the guard ineffective. Guards must also be made of durable materials so that they can withstand the daily abuse of a production environment.
Guards should also ensure that small objects such as tools, nuts, or bolts cannot fall into a guarded area. A small tool or bolt that falls into an area with rotating parts could not only damage the machine but could also become a projectile and seriously injure someone.
Guards are intended to protect workers from the dangers of machinery and should not themselves become a hazard. The edges of sheet metal guards might be sharp or have burrs that could cause lacerations, or the guards might create a new nip point when located near transverse motion.
Ideally, maintenance workers should be able to lubricate parts with the guard intact so that they are not exposed to the hazards of moving parts.
Guards that interfere with production efforts are more likely to be removed or circumvented by the operator, thus placing the operator back into a hazardous situation. Guards that do not interfere may actually increase production because workers are not apprehensive about being injured by the machine.

10. Don’t Let It Happen to You
Avoid machinery unless properly trained
Learn to identify the point of operation and mechanical motion
Make sure all machine guards are in place
Understand guarding requirements
Know who to contact if a guard is missing, damaged, or inadequate
Speaker’s Notes:
Let’s take a look at what we can do to prevent a similar incident from happening at our facility.
Stay away from any machinery unless you are properly trained on the machine’s hazards, guarding requirements, and how to safely work on or near the machine. You must understand the hazards of a machine, even if you are just working nearby.
Learn to identify machine hazards. The point of operation may include cutting action, punching action, shearing action, or bending action. The mechanical motion of a machine may include reciprocating motion, transverse motion, rotating motion, or nip points.
Make sure all machine guards are in place. Before starting the operation of a machine, walk around the machine and inspect all the guards. The guards must be in place, in good condition, and provide adequate protection.
Learn about guarding requirements. Remember, guards must prevent bodily contact with the danger zone, be secured to the machine, prevent objects from entering the danger zone, should not themselves become a hazard, and should not interfere with production.
Know whom to contact if a guard is missing, damaged, or inadequate. Do not operate the machine. Contact your supervisor or maintenance personnel according to the procedures described by your company. It is important that the guard is fixed before the machine begins operation.
Are there any questions?
Thanks for your attention.

11. Quiz
1. Give an example of the type of hazardous action that occurs at the point of operation.
2. How does an interlocked guard protect workers when the guard can be opened?
3. What is the main drawback of an adjustable guard?
4. What is the primary purpose of a guard?
Background for the Trainer:
Remind employees that the quiz is to encourage further discussion and to help you, the trainer, be sure that everyone understands what was discussed.
Print copies of the quiz for participants to take on their own, or go over the questions as part of the training session.

12. Quiz (cont.) 5. What should you do if you find a damaged guard?
6. Give an example of a hazardous mechanical motion.
7. What should you do before starting a machine?
8. How should you approach machinery if you have not been trained?
©2003 Business & Legal Reports, Inc.

13. Quiz Answers
1. Q. Give an example of the type of hazardous action that occurs at the point of operation.
A. Cutting, punching, shearing, or bending.
2. Q. How does an interlocked guard protect workers when the guard can be opened?
A. In interlocked guard is designed to shut off the machine when opened.

14. Quiz Answers (cont.)
3. Q. What is the main drawback of an adjustable guard?
A. The operator must adjust the guard appropriately to provide protection.
4. Q. What is the primary purpose of a guard?
A. Prevent bodily contact with the machine’s hazard.
©2003 Business & Legal Reports, Inc.

15. Quiz Answers (cont.)
5. Q. What should you do if you find a damaged guard?
A. Report the damage to a supervisor or maintenance person.
6. Q. Give an example of a hazardous mechanical motion.
A. Reciprocating, transverse, rotating, or nip points.
©2003 Business & Legal Reports, Inc.

16. Quiz Answers (cont.)
7. Q. What should you do before starting a machine?
A. Inspect the guards to make sure they are in place and in good condition.
8. Q. How should you approach machinery if you have not been trained?
A. Stay away from machinery until trained on hazards and safe work practices.
©2003 Business & Legal Reports, Inc.