How Do We Work Safely With Industrial Robots?
Thu, October 21, 2021

How Do We Work Safely With Industrial Robots?

Robots in the workplace are by no means science fiction as technological advancements have enabled industrial robots, for instance, to assemble, paint, weld, push, and pull products / Photo by: Vincent Diamante via Wikimedia Commons

 

Robots in the workplace are by no means science fiction as technological advancements have enabled industrial robots, for instance, to assemble, paint, weld, push, and pull products, according to Donna McEntee of Occupational Health and Safety (OHS), a news platform dedicated to occupational health and safety professionals. Meanwhile, collaborative robots are equipped with one or more mechanical arms to provide workers with another set of hands. 

Robots are useful in various industries, not just in manufacturing. For instance, physicians have started to use robots to perform surgical tasks to save lives. Even if robots have time and again proven their worth across industries, we still need to consider how we can safely work with them. 

What Are Industrial Robots? 

Considered as a “programmable multifunctional mechanical devices,” industrial robots are designed to move tools, parts, materials, or specialized devices through programmed motions, enabling it to perform different tasks, as explained by the Occupational Safety and Health Administration (OSHA), an agency of the US Department of Labor. 

An industrial robot system includes the robots themselves, as well as devices and sensors required for the robot to accomplish its tasks. The system also includes sequencing or monitoring communication interfaces. While robots are generally used to perform repetitive, hazardous, and unpleasant tasks, they can also spray, conduct machine tool load and unload functions, and more. 

An industrial robot system includes the robots themselves, as well as devices and sensors required for the robot to accomplish its tasks / Photo by: Mixabest via Wikimedia Commons

 

Types of Accidents

The OSHA technical manual enumerated four types of accidents that can occur when closely working with industrial robots. The first category is impact or collision accidents, which result from unexpected movements or program changes related to the robot’s arm or peripheral equipment and comp, as well as component malfunction. 

The second is crushing and trapping accidents that occur when a person’s limb or body parts get caught between a robot’s arm and peripheral equipment. Such accidents may also happen if the individual is “physically driven into and crushed by other peripheral equipment.” Further, mechanical parts accidents occur when the robot’s drive components, tooling or end-effector, peripheral equipment, or its power source break down. Lastly, accidents resulting from leaking high-pressure lines, metal spatter, dust, arc flash, or electromagnetic or radio-frequency interference can also happen. 

Why Do Accidents Occur? 

According to OSHA’s technical manual, accidents occur due to human error, unauthorized access, control errors, mechanical failures, environmental sources, power systems, or improper installations, as cited by McEntee. But the most common cause of accidents is human error. Workers tend to “get comfortable” with the equipment and sometimes complacent about the risks. 

Hence, it is possible to place themselves in unsafe areas when performing maintenance on a robot or when programming it. Since they require complex programming to operate, accidents can also occur as a result of a human-introduced programming error. Considering that industrial robots can perform movements “across a large area,” any change in its material or the environment may affect its pre-programmed movements. Using physical barriers typically safeguard workers from industrial robot hazards. But then again, accidents do happen. 

For example, back in 2017, an employee who worked for an automobile parts manufacturer “leaned through a light curtain” to change a robot’s welding tip. All of a sudden, another robot in the firm energized. The employee was struck by the robotic arm. He was then hospitalized as he sustained a fracture and a dislocated left hip. 

Risk Assesment Is a Priority

Employers should ensure that workers understand and recognize the above-mentioned hazards. Before a business can incorporate robots into its operations, it is recommended to conduct a risk assessment during the robots’ design process. Employers should identify its purpose, physical and operational limitations, and use (or misuse). 

Then, they should pinpoint any “foreseeable hazards and relevant hazardous conditions that may arise.” By conducting risk assessments, employers should try to minimize risk to an acceptable level by determining the appropriate type of functional safety controls. 

Leveraging Risk Assessment to Reduce Risk

The data gathered during the risk assessment process helps employers determine which type of hardware and controls can be used for the safety control system. For example, engineering controls can restrict access to a hazard zone. Such controls may also include electromechanical door interlocks, fixed barriers, and presence-sensing devices like light curtains or pressure mats. These devices minimize the likelihood of workers being exposed to hazardous situations. However, they don’t “reduce the potential severity of the injury.” 

OSHA recommended workers responsible for programming, operating, maintaining, or repairing robots or robot systems to undergo safety training. Workers who receive adequate safety training are expected to demonstrate their ability to accomplish their jobs safely. Administrative controls are the least favorite as they rely on human intervention to reduce the likelihood of harm. Awareness devices like visual warning lights, signs, and audible alarms to warn workers of any danger. Operating and maintenance procedures and training are also examples of administrative controls. 

If in case engineering, administrative controls, and work practice do not provide enough protection, employers must be prepared to provide personal protective equipment (PPE) such as gloves, respirators, hard hats, hearing protection, gloves, and safety glasses to workers. The aforementioned equipment act as a “final layer of defense against injury.” 

Industrial robots help boost productivity and deliver greater efficiencies to businesses. But robots are not perfect as errors and safety hazards can occur. Therefore, it’s important for employers to conduct safety training sessions and risk assessments to minimize the occurrence of accidents. This way, businesses can ensure that robots are operating safely in conjunction with their human co-workers. 

Employers should ensure that workers understand and recognize the above-mentioned hazards / Photo by: Konstantin Pelikh via 123RF