1. A Presentation of the SPI-OSHA Alliance
Machine Guarding for Injection Molding Machines
A Presentation of the SPI-OSHA Alliance
The Society of the Plastics Industry. Inc. (SPI) and OSHA formed an Alliance in the fall of 2002 in order to help employers in the plastics industry provide safer working environments in their plants. This is a national Alliance, signed with Federal OSHA.
As you may know, there are 22 State Plan States that run their own occupational safety and health programs for general industry employers. The rest of the states are covered by Federal OSHA. Although most of the State Plan States have adopted the Federal OSHA Standards, there may be some differences (e.g., California, Michigan). This course is based on Federal OSHA standards.
This course on Machine Guarding and Lockout/Tagout (LOTO) was created by a dedicated team, consisting of experts from OSHA and industry. This is a train-the-trainer course—that is, these training modules not only consolidate all the critical information you need on machine guarding and LOTO, but also prepare you to train employees at your worksite.
The Alliance would like to hear back from you—not only about how well these tools work for you and how many people you train, but also about ideas you may have for other areas that we can work together on to make a safer workplace in our industry.
Please send your comments to Susan Howe, SPI, 1667 K Street, N.W. Suite 1000, Washington, D.C or via at Thank you.
Third Edition - June 2006
The Society of the Plastics Industry, Inc.

2. (Screen Capture of Website)
Our Alliance developed a Web site to provide you a central resource for safety and health information about the plastics industry.
You can link to this site at:
This and the other associated pages are a valuable resource for developing your training program, locating information, and learning how-to’s to provide a safer work environment for your employees.

3. (Screen Capture of Website)
This site contains links to the machine safety training programs developed by our Alliance.
You can link to this site at:

4. Course Objectives
Identify the types of injuries that can occur while operating injection molding machines
Describe the possible causes of these injuries
Identify ways to safely operate injection molding machines
Recognize the importance of a total safety and health approach
This course addresses machine guarding and lockout/tagout safety issues relating to plastics injection molding machines. It does not cover everything you need to know about plant safety.
You’re going to hear a common thread running through this course. Machine safety and lockout/tagout programs are only part of the effective safety and health management system at your plant.
You should use OSHA's Safety and Health Management eTool, with what you will learn in this course, to develop, refine, or improve your company’s goals for addressing safety and health in your workplace.
Additional information on Machine Guarding requirements can be found at the following site:
Additional information on Lockout/Tagout requirements can be found at the following site:

5. (Screen Capture of Website)
One of the tools developed through our Alliance is a Machine Guarding eTool for Plastics Machinery.
OSHA's eTools are "stand-alone," interactive, Web-based training tools on occupational safety and health topics. They are highly illustrated and utilize graphical menus.
OSHA's Machine Guarding eTool has modules on saws, presses and plastics machinery.
You can access these eTools at the following site:
Use the following site to go directly to the Plastics Machinery Machine Guarding eTools:

6. Reasons to Focus on Injuries in the Injection Molding Process
High injury/illness rates
OSHA citations
National Emphasis Program
Site-Specific Targeting
High workers' compensation costs
Plastics is one of the largest manufacturing industries in the US. We have over 1.3 million workers.
And plastics processors are the most frequently cited industry under OSHA's lockout/tagout standard and the second most frequently cited industry under OSHA's machine guarding standards.
Citations for the year October September 2005 are listed below.
For Lockout/Tagout
#Cited #Insp $Penalty Industry Classification
$122, SIC Code 3089
For Machine Guarding
$127, SIC Code 3089
Information about OSHA's Site-Specific Targeting Program (SST) is at the end of this presentation, along with reference materials on OSHA’s National Emphasis Program on Amputations.

7. Types of Injuries Fatalities Cuts and bruises Amputations
Avulsions
Fractures
Cuts and bruises
Sprains and strains
Burns
Electric shock
These are some of the common injuries that occur in the plastic processing industry.
We are focusing today on the more severe injuries—those in the left column.
Fatalities, obviously, are the most severe of all.
Amputations can disable and disfigure. Avulsions should be considered a near-miss to amputations.
Fractures occur when employees are involved in a crushing or
caught-in hazard.
Employees receive burns from hot equipment and from hot plastic.

8. Some Causes of Injuries
Reaching around, under, over or through guards into hazardous areas
Removing or bypassing guards
Reaching into equipment to remove stuck or jammed material
Not using LOTO procedures
Machine/equipment malfunctions
Never attempt to reach around, under, over, or through a guard. If a person standing on the floor can reach over the machine or machine guard into the point of operation, either install new guarding or modify the existing guarding to prevent that from occurring. One common approach is to install a top guard that is either fixed or interlocked, depending on the need for access to the area.
Never remove, alter, or attempt to otherwise bypass a safety interlock.
Do not remove or open a fixed guard for normal operating tasks.
Provide training on the hazards and safety features of the plastics injection molding equipment for all employees who may come in contact with it.
We will discuss LOTO requirements in the second half of the program

9. Causes of Injuries (cont’d)
Lack of recognition of job hazards
Lack of familiarity with the equipment
Inadequate training, comprehension, or both
Operating machines with missing or inoperable guards and improper or inadequate machine maintenance
Speaker should paraphrase the points listed on the slide.
This would be a good time to engage the audience in discussing specific "events" (such as, near misses) that have happened to them or in their work place.

10. Injection Molding Machinery
Horizontal injection molding machine (HIMM)
Vertical injection molding machine (VIMM)
Injection molding is the method of forming objects from granular or powdered plastics in which the material is fed from a hopper to a heated chamber in which it is softened, after which a ram or screw forces the material into a mold.
Pressure is maintained until the mass has hardened sufficiently for removal from the mold.
Injection molding machines are available in a broad range of sizes. They are normally rated by their maximum clamping force, with normal ranges from about tons for "small" machines, tons for "medium-size" machines, and tons for "large" machines.

11. Vertical Injection Molding Machines VIMMs
We are covering both horizontal and vertical injection molding machines today. We are going to begin by highlighting the unique hazards and issues associated with VIMMs in the next two slides.
In spite of these unique hazards and issues associated with VIMMs, the safe operating practices and procedures apply to both types of machines.

12. VIMMs
Combinations of vertical and horizontal clamp and injection configurations of machines
Regardless of the configuration of the machine, basic machine guarding and good safe work practices must be applied
Point of operation
Other moving machine parts

13. Unique Hazards and Issues
VIMMs:
Unique Hazards and Issues
Gravity
Plastic splatter/missing insert
Flying inserts
Unexpected bystander interventions
Gravity presents a unique hazard associated with vertical injection molding machines. Examples include hydraulic line or linkage failure that could cause the movable platen to fall.
Plastic splatter can occur when an insert is missing or misplaced. Example would be failure to place a spoon insert into the mold cavity when the handle is being molded around the spoon insert to make a finished spoon. The missing insert creates an opening that allows plastic to shoot out from the mold and splatter.
Improperly placed inserts can be caught between the mold halves and ejected under great force.
The guarding protects the operator but not necessarily other people who might unexpectedly reach into hazardous areas.

14. Horizontal Injection Molding Machines - HIMMs
Now we will discuss safety issues related to horizontal injection molding machines.

15. HIMMs: Mechanical Hazards
Point of operation
Pinch points
Nip points
Rotating parts
The point of operation is the area where the work actually occurs.
Pinch points can occur where a moving surface comes in close proximity to a stationary surface, and a crushing hazard is created.
Examples include:
Nip points in the injection molding machine include chains and sprockets, belts and pulleys, and gears. Although not part of the injection molding machine, nip points can occur due to mechanisms and motions of mold components (such as core pulls, unscrewing devices, sliding cams, sliding cores, sprue pickers) and auxiliary equipment.
 Rotating parts that might pose a hazard include pump shafts and couplings, die height adjustments, and rotating screws.

16. Potential Injuries from
Mechanical Hazards
Fatalities
Amputations
Avulsions
Crushing injuries
Fractures
These are the injuries that can occur if the machinery is not guarded, or the employee defeats, by-passes or reaches over, under, around or through the guarding into the Point of Operation.
Avulsion is a ripping away of the flesh that does not include bone loss.
An example might be where your finger gets caught in a nip point, you pull it out, and flesh is torn off, but the bone is still there.
It’s impossible to see the scale in this picture, to be able to tell how big a body part can fit in this space, but you should know that IMMs come in many sizes, from small enough to fit on a tabletop to large enough to produce a whole car body. Depending on the particular machine, these potential injuries might be to a finger, arm, head, or entire body.

17. Safety Guards and Devices
Types of guards and devices
Movable guards with interlocks
Fixed barrier guards
Presence-sensing devices
Mechanical safety bars
Locations of guards
Over/around moving equipment
Around electrical hazards
Around thermal hazards
Employers are responsible to ensure that machinery is ordered with adequate guarding or retrofitted to protect employees from exposure to mechanical, electrical, and thermal hazards.
This module contains a reference section listing some ANSI Voluntary Industry Consensus Standards that you may want to consult as you devise your machine guarding.
Newer US-made machines are usually compliant with ANSI machine safety standards, but please note that many older machines have not been retrofitted with updated safeties.
In addition, foreign-made machines may not meet all US safety requirements. When purchasing, leasing or using injection molding machines, it is your responsibility to ensure that they are in compliance with all appropriate safety standards.

18. Operator’s Gate Equipped with redundant interlocks
Electrical
Hydraulic
Mechanical safety bar
Allows the machine to operate only when the gate is closed
The operator's gate allows the operator access to the mold and should be equipped with interlocks (such as electrical, hydraulic, and mechanical) that allow the machine to operate only when the gate is closed.
Do not attempt to override any of the interlocks or to reach over, under, around, or through the operator's gate (or other guards) while the machine is operating.

19. Electrical Interlock
Allows the electrical system to operate and close the clamp
Actuated when the operator’s gate is opened or closed
Prevents clamp from closing when the operator’s gate is open
The electrical interlock prevents the mold from closing when the gate is open.

20. Electrical Interlock Operation
This animation shows the operation of an electrical interlock.
Proper operation of the electrical interlocks should be verified on a regular basis specified by the machine manufacturer, maintenance department, or safety director.

21. Hydraulic Interlock Actuated by opening or closing the operator’s gate
Each hydraulic IMM requires at least one
Prevents clamp from closing when the operator’s gate is open
The hydraulic safety interlock valve prevents the clamp from closing when the operator's gate is open.

22. Hydraulic Interlock Operation
This animation shows the operation of a hydraulic interlock.
Proper operation of the hydraulic interlocks should be verified on a regular basis specified by the machine manufacturer, maintenance department, or safety director.

23. Hydraulic Interlock Operation
Before Activation
After Activation
This slide shows the operation of a hydraulic interlock before and after activation.
Proper operation of the hydraulic interlocks should be verified on a regular basis specified by the machine manufacturer, maintenance department, or safety director.

24. Mechanical Safety Device
Prevents clamp from closing when the operator’s gate is open
Must have at least one mechanical device on all IMMs
The mechanical safety device physically prevents the mold and clamp from closing when the operator's gate is open.

25. Mechanical Safety Device Operation
This animation shows the operation of a mechanical safety device.
Proper operation of the mechanical safety device should be verified on a regular basis specified by the machine manufacturer, maintenance department, or safety director.

26. Other Guarding Rear guard Top guard Parts discharge guard
Feed opening guard
Electrical system guards
Purge guard
Injection barrel cover
We will discuss these typical types of guarding equipment in the next few slides.
Depending on the complexity of your process, your machinery may have more guarding than what is pictured in this course.
Regardless of how specialized, or how simple your manufacturing processes are, employees must be protected from all hazards.

27. Rear Guard
Prevents clamp from closing when interlocked rear guard is opened
Should have at least two interlocks
Prevents access to mold areas
The movable rear guard should be equipped with at least two interlocks that stop clamp motion when the guard is open.
This guard should only be opened for setup and maintenance activities.
Use the front operator's gate for operator access to the mold space.

28. Top Guard
Required if employees can reach over the top of the machine and into hazardous areas
Should be interlocked if movable
On low profile machines, a top fixed guard should also be installed. This prevents a person from reaching over the top of the machine. The majority of molding machines do not require this guard, as they are approximately 9 feet tall.
Guards that are removed only for maintenance, and that require tools to be removed do not need to be interlocked.

29. Top Guards (cont’d)
Additional examples of top guards.

30. Parts Discharge Guard
Keeps employees from reaching under the operator’s gate and into hazardous areas
A guard should be placed at the opening for parts discharge to prevent an employee from reaching under the operator's gate and into the mold area.
A chute, conveyor, or other object can take the place of a guard attached to the machine if it prevents access to this area.

31. Purge Protection Covers the nozzle and purging area
In combination with PPE, minimizes exposure to molten plastic during purging
Window allows observation through purge guard, if equipped
Should be equipped with an interlock
Purge guard
The injection unit can also be controlled via guards. The ANSI/SPI B Standard for HIMMs requires guards to protect the front, rear and top of the purging area. An electrical interlock insures that the guard is in place during the automatic running of the machine or during the purging cycle. Should viewing of the purge area be necessary, a window should be provided that will withstand the splashing of the plastic material without failure.
The purge shield covers the nozzle of the injection molding machine and helps to prevent burns from molten plastic material inside the injection system. The operator may monitor the purging area through the window in the purge shield. Injection unit operation proceeds while the purge shield door is closed, but is interrupted when the door is out of position.
Heater Band Shield
This metal guard cover the barrel and heater bands. It must be in position when power is on and/or the machine is in operation.
Heater band terminal ceramic covers insulator caps should be maintained in good condition. If contact is made with any bare terminal while the power is on, electrical shock may result.
Severe burns may also result if contact is made with hot metal surfaces or heater bands.
Never stand on this shield, as it is not designed to bear weight.
Safety
window
Barrel cover

32. Injection Barrel Cover
Protects from exposure to high voltage and high temperatures
The barrel cover acts as a barrier to block access to the injection unit to prevent contact with high voltage and high temperatures.

33. Grinder Guarding Guarding by: Enclosure over moving components
Anti-kickback flaps in feed throat
Proximity guarding – distance from feed chute to rotating knives
During normal operation the point of operation of the granulator (grinder) is guarded from access by both fixed and interlocked guards.
Many accidents associated with this piece of equipment occur during cleaning operations due to direct access to the cutting knives, both rotary and stationery, that must be cleaned and inspected during changeovers of material type or material color.
During cleaning the rotor and flywheel, the mechanism must be turned manually to access all of the areas that need cleaning. Inertia of these heavy components lends to injuries including cuts, bruises, and amputations.
Proximity Guarding

34. Presence Sensing Devices
Safety mat
Light curtain
Examples of presence sensing devices include: safety mats, interlocked platforms, photo-electric beams, or other similar devices.
Safety Mats:
The operation of the safety mat is easy to understand. The safety mat is a simple, normally open switch. When a specified minimum weight is applied to the safety mat the "switch" closes. This sends a signal to the safety mat controller, which in turn, sends a stop signal to the guarded machine.
Light curtains:
Light curtains have been assuring the safety of operators working at or near dangerous machinery for many years.  The light curtain system works by creating an infra red detection plane across the danger area such that any intrusion into the plane results in a stop signal being sent to the machine and the danger being removed.  Light curtains are an important tool in safeguarding hazardous machinery and have many advantages to the user in allowing excellent visibility of the working operation and speedy access to equipment which in turn promotes efficient working practice.

35. Safety Guards and Devices
Light Curtain
Light curtain specifications vary and should be chosen to suit the application to ensure adequate protection.

36. Presence Sensing Devices
Safety Mat
When using the Light Curtain or the Safety Mat it is important that they are spaced far enough away from the point of operation so that the motion can be stopped completely before the employee would be exposed to the hazard.

37. How to Protect Yourself
Recognize the hazards in the job you are doing
Understand the requirements for guarding machines
Implement guarding solutions
Today, many companies use the Job Safety Analysis/Job Hazard Analysis Process as an effective means of helping reduce incidents, accidents, and injuries in the workplace. It is an excellent tool to use during new employee orientations and training and can also be used to investigate "near misses" and accidents.
Job safety analysis (JSA) is part of many existing accident prevention programs. In general, JSA breaks a job into basic steps, and identifies the hazards associated with each step. The JSA also prescribes controls for each hazard. A JSA is a chart listing these steps, hazards, and controls. There are many commercial vendors of Job Safety Analysis software.
You also may want to consider performing a risk assessment such as ANSI B11.TR Risk Assessment and Risk Reduction - A Guide to Estimate, Evaluate and Reduce Risks Associated with Machine Tools.

38. Emergency Stop Know: Where it is located What it controls
When to use it
The control panel on the front of the injection molding machine features a Red Emergency Stop Button that stops all machine function when pressed.
Emergency stop buttons may be placed at a variety of locations along the equipment to allow workers to immediately stop operation.
In most cases, these are not to take the place of normal shutdown controls.

39. Signs are posted on a machine to inform us of hazardous areas
Signs are posted on a machine to inform us of hazardous areas. We are so used to looking at them that we often do not see them as we are running the molding machine.
At the time of initial assignment and periodically afterward, it is good to review the different safety and warning signs on the injection molding machine and other equipment with employees to maintain an awareness or consciousness of the hazards that they identify.
Signs and Warnings

40. Colors used with Safety Signs have meaning!
DANGER
White Lettering/Red Background
WARNING
Black Lettering/Orange Background
A red sign indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
An orange sign indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
A yellow sign indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.
CAUTION
Black Lettering/Yellow Background

41. High Voltage
Place on each electrical cabinet and/or box containing dangerous high voltage.

42. Rotating Screw
Graphics can give examples of the part that is most likely to receive an injury from the hazard.

43. High Temperature
Effective warning signs have both graphical and written information.

44. High Pressure Place on the purge guard.
Graphics can give examples of the part that is most likely to receive an injury from the hazard.

45. Robots Used to automate repetitive or hazardous tasks
Must be guarded to prevent workers from entering or reaching into hazardous areas
A robot can be attached or placed adjacent to an injection molding machine to automate repetitive or potentially hazardous tasks.
The robot must be guarded to prevent workers from entering or reaching into its space during operation.

46. The Robot
Simple fixes are available to avoid injuries due to robots trapping a person.
Place a fixed guard around the area where the robot operates. This type of guard could be an inconvenience when the robot and/or machine need to be worked on, but it is the most sure way to avoid trapping.
A second method involves using safety mats around the area of operation. A safety mat is a device that disables the operation of the robot when sufficient weight (< 10 pounds) is applied to the mat. . Thus, when a person walks up to the operational area of the robot, they step on the mat and the robot shuts down.
Another method is to create a light curtain around the operational area of the robot. A light curtain operates in the same manner as the safety mats, except that it beams light around the operational area. Then, when one of the light beams are broken, the robot shuts down.
All of these methods keep the person away from the robot during its motions.

47. References for Injection Molding Safety
ANSI/SPI B Horizontal Injection Molding Machines - Safety Requirements for Manufacture, Care and Use
ANSI B Performance Criteria for Safeguarding
ANSI Standards are available at the following web site:
Formed in 1957 to serve as the spokesperson for the U.S. plastics machinery industry, the SPI Machinery Division develops plastics machinery standards for promulgation through ANSI and the National Fire Protection Association
Additional information can be found on the SPI Machinery Division's web site:

48. OSHA's Site-Specific Targeting (SST) Program
OSHA's Site-Specific Targeting (SST) program selects for inspection individual worksites with the nation's highest lost workday injury and illness rates based on data reported by more than 80,000 employers surveyed by the agency. In April of this year, OSHA announced that its site-specific targeting plan for 2006 would focus on approximately 14,000 worksites with higher than average injury and illness rates for unannounced comprehensive safety and health inspections over the coming year. The 14,000 identified sites are establishments located in stated covered by Federal OSHA.
This year's SST program will initially cover worksites that reported 6 or more injuries or illnesses resulting in days away from work, restricted work activity, or job transfer for every 100 full-time workers (known as the DART rate). The average national DART rate in 2004 for private industry was 2.5.
Over the past eight years, OSHA has used a site-specific targeting inspection program based on injury and illness data. This year's program stems from the agency's Data Initiative for 2005, which surveyed approximately 80,000 employers to attain their injury and illness numbers for 2004.

49. OSHA National Emphasis Program on Amputations
On March 26, 2002, the Occupational Safety and Health Administration (OSHA) announced a special national emphasis program aimed at reducing amputations in general industry workplaces. The National Emphasis Program on Amputations targets all types of power presses, including press brakes, saws, shears and slicers. This program is targeted to industries that are considered a high risk for operating equipment that can be very dangerous, as injuries involving these machines are often fatal or result in permanent disability. The plastics processing industry is among the industries under scrutiny for workplace amputations. In keeping with OSHA's mission to identify and reduce or eliminate the workplace incidence of hazards which are causing or are likely to cause amputations, OSHA initiated targeted inspections of workplaces under SIC 3089, Plastics Products, Not Elsewhere Classified. These amputation hazard inspections began in April This is a Federal Emphasis Program. The twenty-four states and two territories which operate their own OSHA programs are encouraged, but not required, to adopt a similar emphasis program. The OSHA directive on this emphasis program is available on OSHA's web site under Regulations and Compliance, subcategory Compliance Directives, No. CPL
Under this new initiative, regional and area OSHA offices will conduct outreach programs to identify, reduce and eliminate workplace hazards associated with these machines. Their programs will be conducted in three parts: outreach; targeting and selection; and inspection. Area offices will obtain and use additional data to identify and add establishments where serious injuries or fatalities related to these machines have occurred.

50. The Job Safety Analysis Process
The Job Safety Analysis (JSA) process is a very effective means of helping reduce incidents, accidents, and injuries in the workplace. It is a multi-step process.
Basic Job Steps
Potential Hazards
Recommended Safe Job Procedures
Break the job into a sequence of steps. Each of the steps should accompany some major task. That task will consist of a series of movements. Look at each series of movement within that basic task.
To complete a JSA effectively, you must identify the hazards or potential hazards associated with each step. Hazards contribute to accidents and injuries. All sources of energy must be identified. It is very important to look at the entire environment to determine every conceivable hazard that might exist.
Using the Sequence of Basic Job Steps and Potential Hazards, decide what actions are necessary to eliminate, control, or minimize hazards that could lead to accidents, injuries, damage to the environment, or possible occupational illness. Each safe job procedure or action must correspond to the job steps and identified hazards.
Everyone involved in implementing a job or task should be present when the JSA is written. The JSA should be reviewed, approved, and signed by the supervisor before the task is started. Understanding every job step is very important. Whenever a job step changes or a new step is introduced, the JSA must be reviewed and updated. Remember, the key reasons for completing a JSA are to encourage teamwork, to involve everyone performing the job in the process, and to elevate awareness.

51. Our sincere thanks to: United Southern Industries, Inc.
OSHA Regions V & VIII
OSHA's Office of Education and Training
OSHA’s Salt Lake Technical Center
Michigan OSHA
The Society of the Plastics Industry, Inc.
United Southern Industries, Inc., for Wayne Wilson’s time and expertise
OSHA Region V, for John Hermanson’s strong support of the Alliance goals and Jim Washam’s time and expertise.
OSHA's Office of Education and Training, for Cathy Cronin’s vision and leadership.
OSHA’s Salt Lake Technical Center for developing the Virtual Tour and the animations for this course.

52. Do you have any Questions?