NIOSH: Robots that Work Alongside Humans Bring New Safety Hazards

The increasing use of robots that work alongside humans brings new occupational safety hazards, but there’s not much data available on how to mitigate risks.

The Washington state Department of Labor & Industries added to the body of knowledge this month when it released safety recommendations for laser guided forklifts and demolition robots. Both reports were issued after workplace accidents, one of them that resulted in death.

The National Institute for Occupational Safety and Health said documentation on how such injuries occur is critical for prevention efforts.

“Currently, there is a lack of standard classification codes for robot-related injuries, which makes it hard to identify the frequency of incidents,” NIOSH said. “Additionally, worker injury data systems do not include detailed information on how a robot-related fatality or injury incident occurred.”

Washington state’s Fatality Assessment and Control Evaluation program (FACE) investigated after a 45-year old worker at a bottled water packaging plant was killed in December 2015. The worker had reached below the forks to remove a strip of plastic that was interfering with the driverless forklift’s sensors. A sticker affixed to the robot warned workers to stay clear of the forks.

The worker had failed to cut power to the machine before he reached under it. Once he removed the plastic, the robot reactivated and brought its forks down, crushing the worker against the vehicle. The man was transported to a hospital, but died from his injuries.

The FACE report says that after the incident the water bottling plant purchased long-handled snipping tools that the workers can use to remove any plastic strips that get tangled in the robotic forklifts.

FACE issued these safety recommendations to all employers that use laser-guided forklifts:

• Incorporate manufacturer safety requirements into written company safety procedures for automated guided industrial vehicles.
• Train workers about the specific hazards and safety requirements associated with automated guided industrial vehicles.
• Emphasize that workers are expected to follow required safety procedures every time, and ensure compliance through periodic refresher training and spot checks.

FACE issued a similar advisory after two incidents in which robotic demolition machines injured workers.

In the first instance, an operator bumped the remote control while attempting to move the demolition machine’s power cable as he worked to demolish a heating, air conditioning and ventilation system. The robot moved and pinned him between its outrigger— the boom that holds the demolition tool—and a wall.

The worker lost consciousness, but co-workers were able to pry him free from the machine. He suffered crush injuries that caused him to miss several months of work.

In the second incident, a worker who was attempting to chip concrete put his foot too close to the machine’s outrigger, which came down and crushed his foot. The machine’s operator had worked in construction for 23 years, but had only five days experience on the robotic demolition machine.

FACE issued these recommendations for workplaces that use robot demolition machines:

• Prepare a job hazard analysis with operators for each new job to identify and control hazards.
• Always stay outside the risk zone when the machine is in operation and do not enter until the machine is put into emergency stop mode or deenergized.
• Consider using a proximity warning system, such as those based on radio frequency identification, to maintain a safe worker-to-machine distance.
• Train operators to manage power cables and to continually monitor the process for hazards and redefine the risk zone.
• Ensure operators always read and follow manufacturer’s provided safety instructions.
• Consider using a spotter to assist the operator.

Washington state is one of seven states that operates its own FACE program. The Centers for Disease Control oversees a national program that covers all states.

The FACE database identifies only two other incidents of robot fatalities:

In 2001, a worker was killed when he stuck his head beneath a robot to inspect the contents of an injection molding machine. The man’s head was caught against the robot’s frame and the robot when the machine rotated.

In 1984, a die cast operator was killed in Michigan when he was pinned between the right rear end of a hydraulic robot and a safety pole.

NIOSH said it established the Center for Occupational Robotic Research to guide the development and use of workplace robots that enhance worker safety.

“The center is building a research portfolio that includes efforts to document risk to workers through surveillance and fatality investigations,” NIOSH said.