Safety has become a watchword throughout the industrial world, forcing manufacturers and users to find innovative ways to minimize or eliminate hazards. Risk analysis and risk evaluation have become two of the mainstream tools that can help product developers and users reduce risks to tolerable levels.
In North America for example, the end-user/ manufacturer is primarily responsible for having machinery that is compliant with the latest safety standards and regulation. In European and Asia-Pacific regions, the responsibility to design and build safe and compliant machinery falls primarily on OEMs. Also, the analytic nature of the new machine safety standards is leading OEMs and end users to work more closely together.
Over the past several years, standards that provide a methodology for understanding risks have helped companies improve the safety of equipment and facilities. These standards provide a structured, repeatable way to spot potential hazards and eliminate them, or to reduce the chance of death or serious injury when some risk is involved with a hazardous job.
ISO 12100 and ANSI B11.0 are two of the most prominent standards for risk analysis. Hints on using these two documents are provided in a Webinar, “Machine safety: Take a Step Into the Future,” that features Andras Szende of TUV Rheinland of North America, Inc., one of the leading companies in safety compliance. The two standards are similar, but have different scopes.
“ISO 12100 is an international standard that addresses safety throughout the life cycle of equipment. In the United States, ANSI B11.0 addresses both equipment suppliers and end users, separately or jointly,” Szende says.
The addition of end users in ANSI B11.0 involves a number of aspects that aren’t included in ISO 12100. Users must consider the conceptual design of the workplace, as well and the buildout, installation and debugging. Operations and maintenance must be considered along with decommissioning.
Many aspects of the two standards are similar. For example, emergency stops, energy isolation and dissipation, and safe access to machinery are all viable techniques for preventing injuries. However, responsibility for training personnel and adding protective devices differs.
“In ISO 12100, training, personal protective equipment and protective guards are all part of the design. They’re not something the user can do to comply with the standard,” Szende says. “In ANSI B11.0 it’s unclear whether all aspects come from the equipment supplier or the end user.”
Risk assessment is a mainstay of both documents. Managers must search for potential hazards, then determine the level of risk that these hazards will cause injury or damage. Determining whether the hazards can be removed or mitigated is the next step.
This approach requires multiple iterations – after hazards are eliminated or their impact is reduced, analysts must re-examine the altered design using the same guidelines. At all phases, those performing risk assessments must consider a broad range of potential issues.
“A lot of hazards don’t come directly to people’s minds,” Szende says. “Things like vibration and people’s posture when they’re standing next to a machine. Dust, emissions and fumes are all potential hazards.”
The standards help developers and users focus issues that have more severe consequences. When there’s a likelihood of severe injuries or death, employees tasked with improving safety must take all necessary precautions to eliminate or reduce risks. Often, that requires many steps. For example, designers must look at the potential problems that come when they change a design to eliminate an issue
“Product designers must use inherently safe design measures,” Szende says. “At each iteration, designers need to estimate risks, evaluate the risks and compare them to other risks, when applicable.”
The standards address broad types of equipment that can be used in many environments, so they don’t provide specific directions for removing risks. Instead, they give end users tools and techniques for ensuring that equipment can be used without injuries or damage to end products, equipment or facilities. A range of protective techniques are viable, though eliminating potential problems is the most effective way to guarantee that machinery can be used safely throughout its lifetime.
“Designing out a potential hazards is the most preferable way to reduce risk,” Szende says. “In ANSI B11.0, engineering controls and safeguards like barriers and interlocks are part of the solution. It also permits awareness devices like warning lights sirens and labels, though warning labels and manuals, cannot be the primary safety technology.”
When equipment is installed, users must follow the manufacturer’s instructions for setup. If they make substantial changes or alter the machinery and/or its protective equipment, manufacturers usually can’t be held responsible.
“If users modify a machine, doing something like removing a guard, they take responsibility for that machine,” Szende says.
Szende notes that there are a number of other standards that can help developers and users create more effective safeguards and comply with various laws and regulations. Some of them are fairly generic, such as EN ISO 13849-1, which uses factors such as mean time to dangerous failure to determine whether risks have been reduced to acceptable levels.
Others focus on industry and equipment segments. Szende cited ANSI/RIA R15.06, which focuses on robot safety, as a document that augments broader safety standards like ISO 12100 and ANSI B11.0. He notes that standards bodies are focusing more on harmonization, so that varying standards complement each other. That’s a change from the past, when a lack of commonalities sometimes made it difficult to meet requirements set by different governing bodies.
Improved safety brings many benefits for companies and employees alike. Eliminating risks keeps workers safe while improving morale and productivity. Any time machinery in the plant causes injury or damage, there’s downtime that impacts the company’s bottom line.
Standards are playing an increasingly important role in safety, helping manufacturers, equipment owners and operators work in environments that minimize the chance of injuries. Complying with international rules and regulations is yet another benefit of employing safety standards.
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