Plastic Molding Safety

The plastic molding industry uses powered machines such as rollers, presses, compression plates, heat sealers, and cutting knives to form plastic products. The moving, rotating, cutting and hot equipment you use in plastic molding poses safety hazards.

Get specific training on your job tasks and the equipment and materials you use. Learn the mechanical hazards of each machine you use. Nip points are areas of equipment where you could get caught between two parallel, rolling parts. Rotating parts can pull hands, arms, hair, and clothing into the hazard area. Pinch points are the areas where you can get caught between moving machine parts or between a moving and stationary part. The point of operation is the area of the machine where the material is worked.

All of these areas are hazardous and pose severe injury and amputation risks. Label each machine with the hazard point(s) and type(s). To control the risks of machine injuries, use guarding to cover and protect the nip points, pinch points, and points of operation. In addition, guard and protect heated surfaces to prevent burns. You can also use heat-resistant gloves or clothing to protect yourself if you must work near heated surfaces.

As a guarding example, Cal/OSHA requires a sliding gate guard on injection molding machines that shuts off the machine if the gate opens. This prevents a worker from getting their hands pressed and crushed by the dies. These machines can also be guarded using two-handed, constant pressure controls that will stop the machine unless the operator has both hands on the controls.

Cal/OSHA also has guarding requirements for thermo-setting plastic molding presses and other point of operation hazards on machinery that include gates and barriers to prevent a hand or body part entering the hazard zone. Presence sensing devices will shut the machine off if the operator is in the hazard area. Two hand controls or trip devices shut off the machine if operator’s hands let go or enter the hazard area.

Pull-out, hold out and restraint devices physically restrain the operator’s hands from entering the hazard area. These devices should be carefully adjusted to ensure they restrain hands to a safe distance. If there are multiple operators using a machine, each operator should have one of the above safety controls securely attached to them. Note that hand feeding tools can be used to place and remove materials in presses and other machines, but they should not be considered guards or used in place of guards or other safety controls.

Carefully inspect machines before you use them and take them out of service if they are not operating properly. Before you perform maintenance, lubrication, or clear a machine jam, use lockout /blockout procedures to ensure that it does not start up while you have a hand or tool in a hazardous machine area. If you remove a guard for maintenance or inspection, replace it before you operate the machine.

Work in a well-lit area with good housekeeping that is free from tripping hazards. Clean up dust, scraps, and spills of plastic materials that can pose slip hazards.


The above evaluations and/or recommendations are for general guidance only and should not be relied upon for legal compliance purposes. They are based solely on the information provided to us and relate only to those conditions specifically discussed. We do not make any warranty, expressed or implied, that your workplace is safe or healthful or that it complies with all laws, regulations or standards.

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