In manufacturing, safety is a basic need, not only for the health of workers but also for the efficiency and sustainability of manufacturing plants. But what are the best practices around safety when it comes to automation? Each form of technology and procedure has different standards that go with them, which can be difficult to manage and understand depending on the technology being used, and how it is being used.
About the Author: Jim Ford
Jim Ford is engineering director at Concept Systems, a certified member of the Control System Integrators Association (CSIA). For more, visit the company profile on the Industrial Automation Exchange.
The best place to start is by understanding the current state of your safety systems, which is done by conducting a risk assessment. Performing a risk assessment evaluates the safety of a workspace and is an important first step of establishing a comprehensive safety program.
A risk assessment defines hazards with tasks, and rates them based on categories: severity of harm possible, frequency of interaction, and ability to avoid the hazard. The rating standards for automated assets are defined by ISO 12100, Safety of Machinery. The rating goes from “a” to “e”, with “e” being the most dangerous performance level. It is then up to each organization to mitigate the risks identified by an assessment.
Risk mitigation typically is managed in one of three ways. The best form of mitigation is to design out a risk: removing it from the system. For example, if there is an open chute into a wood chipper, then add a fixed cover so there is no access to the chipper.
If the hazard cannot be mitigated out, the next move is to create a physical barrier. In the wood chipper example, this may be a fence that keeps personnel away from the open chute.
Finally, if neither of the first two mitigation options are possible, the final form of mitigation is to implement information for use. This means providing signage and training for employees to protect them as much as possible from the hazard.
As a systems integrator, Concept Systems has done a multitude of safety mitigation projects, projects with the sole focus on improving the functional safety of equipment. When it comes to developing a full safety program, that program should include the following phases: design, assess, mitigate, verify and validate, and then re-evaluate. These phases act in a circle as standards and plants change, meaning they should be re-evaluated on a continual basis.
In the past, safety could be a give-and-take situation, where operational reliability was often sacrificed in order to improve safety. However, technology advances have improved the ability of organizations to provide safe equipment operation in conjunction with improving line performance.
For example, zoned safety scanners can monitor a space, and respond accordingly to what the scanner sees. If a worker gets close to a machine, then the scanner automatically slows the machine down to a safe speed. If a worker moves into an unsafe zone, then the scanner sends a signal to shut down the equipment. Compare this technology to light curtains of the past, where if a worker breaks the plane, then the machine shuts down completely. It is all or nothing, and nuisance trips abound.
It can be very helpful to bring an integrator into the design phase of a project like this, so that hazards can be designed out and the best use of technology can be made. An integrator partner can manage the entire safety enhancement process from design, hardware selection/procurement, integration, commissioning, and training, establishing standards along the way, while keeping in mind the specificities of the individual plant sites.
Unfortunately, sometimes safety is on the back burner of a company’s concerns, and the consequences are dire, as in the case of Trenton Howe. On August 23, 2018, Howe made plans with his mother for dinner that evening and left for work at a manufacturing facility in Oregon. He never left the plant alive.
Howe was killed by one of the plant’s festoon machines, a piece of equipment that cools down the rubber strips that are manufactured to be ready for shipping. The machine activated while he was inside of it, helping a coworker with maintenance.
In a report from OSHA, it is stated that before the accident, there was nothing being used to stop employees from accidentally coming into contact with the dangerous machinery. This is a situation that could have been easily avoided had safety been a consideration at some point along the way.
We tell Trenton’s story to spread awareness about the importance of safety, in hope that safety is discussed before an accident happens, not after.
