EHS professionals may agree that employee safety is a top priority for their companies. They also may realize that automation technology – including machine safety equipment – can deliver positive, business-enhancing benefits for EHS programs when effectively implemented. However, identifying and mitigating risks can be a challenge.
The best way to determine and illustrate safety is through a risk assessment. Performing a risk assessment can help chart a clearer course for an EHS strategy to effectively protect a company’s investments in personnel and equipment. A thorough assessment helps identify the areas of risk within a facility and pinpoint the best people, processes and technologies to minimize those risks. It also helps companies establish acceptable levels of risk for their operations.
The role of EHS professionals is to initiate the risk assessment process and help lead companies in efforts to conduct assessments. Engineers, as well as third-party safety specialists, can help EHS professionals execute successful safety assessments and determine appropriate risk mitigation measures.
In the United States, risk assessments provide a method for complying with the OSHA stadard CFR 1910.147(a)(2)(ii)(B), known as the “Minor Service Exception to Lockout/Tagout.” The minor service exception allows employees to access hazardous areas of a machine to perform what is considered minor services, such as routine minor tool changes and adjustments during normal production hours, without performing a full lockout/tagout.
Manufacturers also can better comply with most global machine safety standards by conducting risk assessments. For example, the EN ISO 13849-1 international safety standard requires equipment users to define a performance level, involving calculations that include diagnostic coverage, mean time to dangerous failure, architecture and common-cause failures to validate that the performance level has been achieved to keep operators safe. All of this information can be obtained through a risk assessment.
Knowing the Risks
In short, the goal of a risk assessment is to help define a piece of equipment’s level of safety and freedom from unacceptable risk. A machine might be considered safe if it can be operated and maintained under minimum exposure and with minimum risks to its operator and environment. A risk assessment is an effective method for properly identifying and assessing the real hazards involved in operating a particular machine.
Through the process, companies are able to analyze employee activities to determine the risks they encounter through defined work practices, or the risks they could bring to the facility due to limited training or experience. A risk assessment also identifies risks inherent to workers, plant equipment or the environment through potential environmental exposure or limited safety protection measures in the event of improper installation or failures of the equipment on the plant floor.
A formal risk assessment process also documents any identified risks, the protective measures and safeguards implemented to mitigate them and the residual risk remaining once these mitigation methods are deployed. Illustrating due diligence through documentation and good engineering practices in providing a safer work environment potentially can help a company lower its risks of litigation in the event of an incident.
A risk assessment serves as an effective method for properly identifying and assessing the real hazards involved in operating equipment on the plant floor. The best starting point is an understanding of all known machine characteristics and limits for each piece of equipment. To effectively gather this information and to implement solutions that best address the identified hazards, EHS staff should partner with others in the organization, including engineers, or with third-party machine safety specialists. The team then should follow six key steps to maximize the effectiveness of the risk assessment process.
Step 1: Define the Risks
To define all the known characteristics and limits of each machine, detailed information about individual machines and their intended use must be documented. This information generally is collected once and then maintained as part of the risk assessment file for the life of each piece of equipment.
It is important to capture accurate data because it will be used as justification for any conditional assumptions made later in the risk assessment process, such as when considering the speed and/or potential of a hazardous energy source or component.
Developing the limits of every machine should include documenting various pieces of information about every individual machine’s general use – for example, operational specifications, energy sources, production rates, expected production environment and expected training or experience of an operator or technician. This is the beginning of the documentation process, and the information should be collected prior to beginning the next phase of assessment.
Step 2: Indentify the Tasks
Next, identify all known hazards associated with operating and maintaining the facility’s equipment. To accomplish this, first identify and list all known routine, repetitive and integral tasks that personnel perform while operating the equipment. Methodically step through each task to allow hazards to be more easily identified. Consider tasks for all affected personnel such as operators, maintenance, engineering, custodial, quality control and so forth.
For example, a janitorial task may require cleaning scrap from around or underneath a piece of equipment. A potential hazard could be an unexpected startup of a machine while the employee reaches or has climbed under it for cleaning. Be sure to reveal as many potential hazards as possible by asking personnel to describe their exact actions while completing the task.
Identify and document any conditional exposure to machine-based hazards. Guests may be exposed during facility tours, or subcontractors who must work in proximity of the equipment may be exposed during their work. Hazard identification should provide a clear list of all reasonably foreseeable hazard scenarios – even seemingly improbable hazards such as unexpected startup of equipment.
When conducting the assessment on the plant floor, it also is a best practice to photograph each potential hazard and include this in the risk assessment documentation. This will provide reference material for subsequent risk assessment processes.
Step 3: Estimate All Known Risks
The next step involves estimating the components of risk associated with the hazard exposure in order to calculate an ultimate risk and/or risk reduction level. While various safety standards may have slightly different definitions, risk can be generalized as the combination of the severity of harm and the probability of the occurrence of that harm.
When identifying hazards and estimating risk, it is necessary to maintain a level of conservativeness, while incorporating common sense and experience. For instance, many companies make the mistake of planning for the worst but disregard the likelihood of less severe but more frequently experienced incidents.
Step 4: Evaluate the Risks
After estimating and documenting the risk parameters, use the graph or matrix provided with the methodology to tabulate an initial risk value. This initial risk value then will be evaluated relative to acceptable risk established by the company. This generally is determined to be some fixed value in the matrix, but also will require some rationalization by the team.
Even if the initial risk is determined to be of an acceptable level, companies should apply some level of mitigation. It is important that low-risk items are identified and assessed, as these less-severe risks can lead to highly severe incidents.
If the initial risk is determined to be unacceptable, the risk assessment team must evaluate the task and hazard exposure in order to recommend new safeguards and mitigation measures.
Once the risks are fully defined and understood, they must be designed out or mitigated to the greatest extent possible. Risk mitigation measures physically improve the machine and production process to reduce the potential of personal injury and environmental or property damage. A variety of effective measures can accomplish risk mitigation. For example, using safeguarding equipment – such as light curtains, safety relays and cable pull switches – helps reduce risk to employees.
Step 5: Reduce the Risks
If the risk has been evaluated as unacceptable, apply risk mitigation measures to reduce the risk to an acceptable level. Ideally, design it out of a machine or process all together. This usually can be accomplished during the conceptual design phase when process functional requirements, as well as required operational and maintenance tasks, initially are defined. This will allow engineers to more effectively minimize hazards – such as pinch points or sharp edges – that otherwise would require safeguarding. If the hazard practically cannot be minimized, then engineers will need to apply safeguarding to effectively reduce the risk.
Ideally, EHS professionals will help the team take a hierarchical approach to risk reduction. This approach is defined by a qualitative scale of safeguarding effectiveness. The top measure (design it out) being the most effective, while the bottom measure (personal protective equipment) is least effective. This globally accepted risk-reduction hierarchy provides an effective risk-reduction strategy.
Step 6: Estimate the Residual Risk
Finally, the team needs to calculate residual risks to determine if the newly installed safeguards have created new potential risks. Once residual risk is calculated, re-evaluate whether an acceptable risk level was achieved. In some cases, the process of risk reduction for a single hazard may have to be implemented several times before the risk is mitigated to an acceptable value.
In addition, the team must ensure that newly applied safeguards allow personnel to operate equipment safely and maintain productivity. For example, if the newly installed safeguard impedes a worker’s ability to perform a job quickly and comfortably, the worker might choose to override or remove the safeguard, which causes a new and potentially higher risk.
Follow Up with Training
After implementing and documenting the process, managers need to provide appropriate training and supervision. This is critical to make sure operators understand all pertinent safety measures, including proper use of personal protective equipment, and how to effectively operate the machines and safely perform their work. It also includes clearly defining and delineating their tasks and processes from those tasks to be implemented by specialized and trained maintenance personnel.
Measuring the effectiveness of training is a process, not an event. Ongoing activities, including behavior-based observations and simple performance evaluations, are effective tools in helping confirm the effectiveness of training. The result of effective behavior changes and appropriate safeguarding designs can be a reduction in incident rates and the associated cost impacts to the corporation.
By understanding the need for and elements of risk mitigation, EHS professionals can shift how management views their roles from a negative focus (e.g., infraction and incident reports) to a positive effort that can yield cost savings, increased productivity and improved morale.
Mike Miller is a FS TÜV expert for global safety market development at Rockwell Automation.