ROBOTS: How to Comply with Safety Requirements for Industrial Robots

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When the cartoon “The Jetsons” premiered in 1962, the futuristic world it portrayed must have seemed very far-fetched. Although we’re still waiting for the flying cars, robots have become a part of our life. In fact, they’re a common sight in manufacturing and other industrial settings where they’re used for tasks such as spray painting, welding, materials handling and assembly. Industrial robots are very useful but they do pose hazards. And, as an Ontario company just found out, failing to protect workers from these hazards has consequences. The company was fined $100,000 after a robot that was supposed to be put into manual mode automatically restarted and hit a worker, breaking his arm [Linamar Holdings Inc.].

What are companies required to do to protect their workers from the hazards posed by industrial robots and robotic systems? We’ll explain the requirements under both OHS law and the Canadian Standards Association (CSA) Z434 standard on industrial robots and robot systems – Click Here.

OHSINSIDER: Members can access links to industrial robot resources – Click Here!

Defining Our Terms

Industrial robots are multifunctional mechanical devices designed to perform a variety of tasks through programmed motions. An industrial robot system includes not only industrial robots but also any devices, sensors, control panels, safeguards, etc. required for the robot to perform its tasks.

In addition, as the guide to Alberta’s OHS Code 2009 explains, robot safety can be divided into three major areas:

  • Safety in the manufacturing, remanufacturing and rebuilding of robots;
  • Robot installation; and
  • Safeguarding workers exposed to the hazards associated with the use of robots in the workplace.

This article focuses on the last area.

WHAT THE LAW SAYS

(Click here to view the Know the Laws of Your Province) Canadian jurisdictions handle the hazards posed by industrial robots in two ways:

Special Robot Section

Four jurisdictions—AB, BC, MB and SK—have specific sections in their OHS regulations on industrial robots and robot systems. These sections take one of two approaches:

Adopt CSA standard. AB and BC simply require all industrial robots and robot systems to comply with CSA Z434. But they refer to different versions of the standard. BC adopts CSA Z434-94, while Alberta adopts CSA Z434-03 (R2008), the latest version. BC has no other specific requirements for industrial robots. Alberta also has additional requirements for workers “teaching” a robot—that is, leading the robot through the desired sequence of events by activating the appropriate buttons or switches.

Set detailed requirements. Manitoba also requires industrial robots and robot systems to comply with CSA Z434-03. But it also has its own detailed requirements for industrial robots and robot systems beyond the CSA standard. Saskatchewan also has its own detailed requirements. The MB and SK requirements are similar:

  • Employers must develop and implement safe work procedures for the installation, operation, use, teaching and maintenance of robots and robot systems;
  • Employers must ensure that robots and robot systems comply with the manufacturer’s recommendations and specifications;
  • Robots and robot systems must have safeguards to prevent workers from entering the “restricted work envelope”—that is, the danger zone surrounding a robot—while the robot or robot system is moving;
  • The primary controls must be located outside the restricted work envelope, arranged so that the robot or robot system is clearly visible to the worker operating the primary controls and unable to be activated inadvertently; and
  • Employers must ensure that workers operating robots or robot systems have a readily accessible emergency stop device.

General Duty Clause

The remaining 10 jurisdictions—Fed, NB, NL, NT, NS, NU, ON, PE, QC and YT—don’t directly address the hazards posed by industrial robots in their OHS regulations. But don’t assume that this omission means employers in these locations don’t have a duty to protect workers from these hazards. The “general duty clause” in each of these jurisdiction’s OHS laws likely requires employers to protect their workers from the hazards posed by industrial robots. Some of these jurisdictions have even acknowledged that robots pose a threat to workers. For example, Nova Scotia has a video available on robotics that “outlines the dangers of working around robots and the need for proper protections to be used by maintainers and other workers, proper fencing, guarding and warning signs to protect all concerned.”

In addition, the lack of specific industrial robot requirements hasn’t stopped jurisdictions from fining companies for safety incidents involving robots. For example, in May 2006, an Ontario company was convicted at trial of violating lockout requirements in the Industrial Establishments Regulation after a worker repairing a robot suffered a fractured skull when the robot’s arm suddenly activated and struck him. The court fined the company $150,000. And, of course, we’ve already mentioned the $100,000 fine against the Ontario company in the Linamar Holdings case. In fact, it’s likely that many of the requirements in the OHS laws that relate to equipment and machinery in general, such as guarding and lockout requirements, would also apply to robots, which are essentially very sophisticated pieces of machinery.

CSA Z434

CSA Z434 covers the manufacture, remanufacture, rebuild, installation, safeguarding, maintenance and repair, testing and start-up, and personnel training requirements for industrial robots and robot systems. (This standard is under review and set to be updated.) Because CSA standards are voluntary, companies don’t have to comply with them unless the jurisdiction specifically incorporates the standard into its OHS regulation as AB, BC and MB have. But it’s wise to consider complying with this standard even if you’re not located in one of those provinces. Courts may view CSA Z434 as a best practice for industrial robots and consider a company’s compliance with the standard a factor in determining if it showed due diligence.

Insider Says: To view CSA standards that have been adopted by the OHS laws for free, go to http://ohsviewaccess.csa.ca/default.asp. To buy standards such as CSA Z434, go to www.shopcsa.ca.

HOW TO COMPLY

Here’s what you should do to ensure that your company adequately protects workers from industrial robot hazards:

Conduct a Risk Assessment

You can’t protect workers from industrial robot hazards unless you know what those hazards are. So conduct a risk assessment of the industrial robot or robot system. Sec. 9 of CSA Z434-03 and the guide to Alberta’s OHS Code 2009 have similar suggestions for risk assessments of a robot or robot system. In general, they recommend that you consider:

  • The size, capability and speed of the robot;
  • The applications and process;
  • The anticipated tasks that it will perform and the hazards associated with each task;
  • Foreseeable jobs associated with the robot, such as teaching, maintenance and repair, and the hazards associated with each job;
  • Anticipated failures;
  • The likelihood of failure occurring and the probable severity of any resulting injuries; and
  • The level of expertise of workers exposed to the robot’s hazards and the frequency of their exposure.

Install Safeguards

As with other types of machinery and equipment, the use of safeguarding devices is critical to protecting workers from industrial robot hazards. Safeguards do two things to protect workers:

Prevent workers from entering restricted work envelope. The work envelope is the area surrounding the robot up to its maximum reach. The restricted work envelope is that portion of the envelope to which the robot’s motions are restricted by limiting devices. Entering this area while the robot is in motion can be very dangerous. So it’s important to use safeguards, such as fences, interlocked gates or other fixed barriers, to keep workers out of the restricted work envelope. Saskatchewan also requires the use of a clearly visible line on the floor identifying the restricted work envelope. You can also use signs, flashing lights or alarms to alert workers when they’ve strayed into the danger zone.

Stop the robot if a worker or any part of a worker enters the restricted work envelope. You must also have additional safeguards in place to stop the robot if a worker manages to get into the restricted work envelope despite your safeguards. Examples:

  • Safety light curtains or screens;
  • Devices that scan the area;
  • Safety mat systems;
  • Single and multiple safety beams; and
  • Radiofrequency/capacitance-sensing safety systems.

Develop Safe Work Practices

Create and implement safe work procedures for the installation, operation, teaching and maintenance of industrial robots and robot systems. For example, require robots to be locked out and moving parts blocked or pinned before maintenance or repair work is done on them. And bar workers from entering the restricted work envelope while the robot is turned on or in motion.

“Teaching” is a job unique to industrial robots and robot systems. Essentially, workers must train robots on how to do their tasks. They can teach the robot by physically guiding it’s arm through the pattern of motions or using a “pendant”—that is, a device like a remote control that the worker uses to walk the robot through the steps slowly, recording each step. Either approach is particularly hazardous because it requires the worker to be in the restricted work envelope while the robot is in operation. So AB, SK and CSA Z434 spell out special safe work procedures for workers teaching robots. Under AB’s and SK’s teaching requirements, employers must ensure that:

  • Only the worker teaching the robot is allowed in the restricted work envelope;
  • The robot system is under the sole control of the worker doing the teaching;
  • When the robot is under drive power, it operates at slow speed only or at a speed deliberately selected and maintained by the teaching worker;
  • The robot won’t respond to a remote interlock or signal that would activate it; and
  • The teaching worker leaves the restricted work envelope before returning the robot to automatic operation.

Train Workers

Naturally, you must train workers on the industrial robot safe work procedures. According to CSA Z434, any worker who programs, teaches, operates or maintains a robot or robot system should be trained on the associated hazards and safe work procedures. Basic training should include:

  • Relevant industry standards;
  • The robot manufacturer’s safety recommendations;
  • Safe work procedures, including lockout and emergency procedures; and
  • Safeguards, including their types, functions and limits.

Depending on workers’ particular jobs, they’ll additional specialized training. For example, a worker who operates a robot must be trained on the robot’s tasks, the hazards associated with each task and responding to abnormal or unexpected events. And make sure you document workers’ training on industrial robots and robot systems and ensure that workers actually follow the practices they were taught.

Conclusion

Industrial robots are often used to perform certain tasks or jobs that are particularly dangerous for workers. But robots themselves pose a hazard to workers. So it’s essential that you ensure that your company doesn’t protect workers from one hazard by automating a process with robots only to expose them to another hazard without adequate protection.

SHOW YOUR LAWYER

Linamar Holdings Inc., Ontario Govt. News Release, March 24, 2010