Due to the increased use of robotics and computer automation for many job functions that have historically been performed by employees raises, besides the traditional personnel and employment issues, a host of workplace safety issues.
The U.S. Occupational Safety and Health Administration’s (OSHA) has been working to address potential safety hazards posed by robotics in the workplace for many years. As early as 1987, in OSHA’s Guidelines for Robotics Safety, Directive No. STD 01-12-002, OSHA noted that “industrial robots can be used to perform hazardous tasks but in doing so they can create new hazards. With the burgeoning use of robots in industry, it is feared that without adequate guarding and personnel training, injury rates for employees working with robots may increase.”
Workplace Robotics Safety
Employers traditionally have called upon robots to perform unsafe, hazardous, highly repetitive, and “unpleasant” tasks, reducing potential hazards associated with those specific functions. Early robots, which mainly conducted a pre-programmed task and did not have any “intelligence” as many robots do now, created potential hazards not only under normal operating conditions, but also during “programming, adjustment, testing, cleaning, inspection, and repair periods.”
During workplace robot functions, the operator, programmer, or maintenance worker may temporarily walk within the robot’s “work envelope” (the area around the robot where performs its task) while power is available to moveable elements of the robot. This created potential machine guarding, lockout/tagout, and electrical safety hazards, among others. In addition, as industrial robots have advanced over the years, they have performed increasingly complex tasks with multiple tools and variable programmed motions, potentially exposing more employees to different hazards.
OSHA’s lockout/tagout regulations require employers to protect employees from unexpected energization of machinery by, among other things, dissipating all sources of energy when the machines are not in use and installing a lock. With robots, the primary source of protection from unexpected movement is a “programmable logic controller” or “PLC.” PLCs limit robots from moving when not performing their pre-programmed tasks and functions or if a certain condition is met - i.e. an interlocked door is open. While these PLC devices typically “fail to safe,” OSHA has been reluctant to accept them as equally effective means of employee protection along the lines of machine guarding or lockout/tagout.
Now, some thirty years after their widespread appearance in the workplace, robotics and computer automation have permeated nearly every industry, including manufacturing, warehousing, and even retail, potentially exposing additional workers to hazards. In Japan, some coffee shops now serve coffee utilizing robotic “baristas.”
OSHA’s Online Technical Manual Regarding Workplace Robotics
While OSHA has not promulgated regulations specifically covering use of robots in the workplace, OSHA has created an online technical manual to inform employers about the hazards associated with robotics and automated machinery, such as those which may result from malfunctions or errors in the programming or interfacing with peripheral equipment. Operational changes with the process being performed or the breakdown of other machinery or electronic sensors could also cause the robotics to react in an unwanted and hazardous manner. In its tool, OSHA identifies the following as important considerations for any employer intending to use robots in the workplace:
I. Types of Accidents. Robotic incidents can be grouped into four categories:
- Impact or Collision Accidents. Unexpected movements, component malfunctions, or unpredicted program changes related to the robot's arm or peripheral equipment can result in contact accidents.
- Crushing and Trapping Accidents. A worker's limb or other body part can be trapped between a robot and other peripheral equipment, or the individual may be physically driven into and crushed by other peripheral equipment.
- Mechanical Part Accidents. The breakdown of the robot's drive components, tooling or end-effector, peripheral equipment, or its power source is a mechanical accident. The release of parts, failure of gripper mechanism, or the failure of end-effector power tools (e.g., grinding wheels, buffing wheels, deburring tools, power screwdrivers, and nut runners) are a few types of mechanical failures.
- Other Accidents. Other accidents can result from working with robots. Equipment that supplies robot power and control represents potential electrical and pressurized fluid hazards. Ruptured hydraulic lines could create dangerous high-pressure cutting streams or whipping hose hazards. Environmental accidents from arc flash, metal spatter, dust, electromagnetic, or radio-frequency interference can also occur. In addition, equipment and power cables on the floor present tripping hazards.
II. Sources of Hazards. The expected sources of potential robotics hazards include:
- Human Errors. Human errors in the programming, interfacing peripheral equipment, or connecting live input-output sensors to the robot or a peripheral device can cause dangerous, unpredicted movement or action by the robot. The incorrect activation of the "teach pendant" or control panel is a frequent human error. The greatest problem, however, is operators’ familiarity and complacency with the robot's redundant motions so that an individual places himself in a hazardous position within the robot’s “work envelope” while programming the robot or performing maintenance on it.
- Control Errors. Intrinsic faults within the PLC control system of the robot, errors in software, electromagnetic interference, and radio frequency interference. In addition, these errors can occur due to faults in the hydraulic, pneumatic, or electrical sub-controls associated with the robot or robot system.
- Unauthorized Access. Entry into a robot's safeguarded area is hazardous because the person involved may not be familiar with the safeguards in place or their activation status.
- Mechanical Failures. Operating programs may not account for cumulative mechanical failure, resulting in faulty or unexpected operation.
- Environmental Sources. Electromagnetic or radio-frequency interference (transient signals) could affect robotic operation and increase the potential for injury to any person working in the area.
- Power Systems. Pneumatic, hydraulic, or electrical power sources that have malfunctioning control or transmission elements in the robot power system can disrupt electrical signals to the control and/or power-supply lines. Fire risks are increased by electrical overloads or by use of flammable hydraulic oil. Electrical shock and release of stored energy from accumulating devices also can be hazardous to personnel.
- Improper Installation. The design, requirements, and layout of equipment, utilities, and facilities of a robot or robot system, if inadequately done, can lead to inherent hazards.
While, again, OSHA does not have regulations specific to robots in the workplace, employers would be wise to conduct job hazard analyses and evaluate any existing or potential robotic equipment installation, to abate any hazards posed by these machines.
Safety Regulation of Autonomous (Robotic) Vehicles
The ongoing robot revolution has ventured into the future of passenger and commercial vehicles. Some employers have embraced the possibilities of a potential transition to autonomous (technically, “robotic”) vehicles as an opportunity to limit driving-related hazards to their employees .
In a recent study, the U.S. Department of Commerce found that 15 million US workers (about one in every nine workers) drove vehicles as part of their jobs. These jobs are concentrated in the transportation and warehousing industries. The study highlighted that the fatality rate (per 100,000 full-time equivalent workers) for motor vehicle operators from on-the-job roadway incidents involving motor vehicles is ten times the rate for all workers, and the numbers of roadway motor vehicle occupational injuries resulting in lost work time (per 100,000 full-time equivalent workers) is 8.7 times as large as that of all workers.
It should be noted that automated vehicles present their own hazards. OSHA has not yet weighed in on how employers should address hazards posed by autonomous cars and trucks at their facilities.
With regard to driving on public roads, the U.S. Department of Transportation and the National Highway Traffic Safety Administration (NHTSA) recently released new federal guidance for Automated Driving Systems (ADS), which should provide preliminary guidance with regard to some of the safety issues posed by autonomous vehicles. Employers should watch these developments closely, as new technologies change the marketplace and potentially affect employee safety.