Understanding "tolerable risk": How safe is safe?
The concept of “tolerable risk” can be confusing. Risk is inherent in manufacturing work, and if you accept no risk at all, you won’t get anything done. However, you’re also responsible for ensuring the safety of your workers. As a risk assessment provider, Omron can help you meet your level of acceptable risk, but the risk threshold is set by you, not by Omron.
The gist of the matter here is that “tolerable risk” is a subjective, company-specific policy. Once you decide what level of risk you’re willing to accept, then that’s the standard you need to hold yourself to. Omron can’t tell another company what is and what isn’t a tolerable risk level. (Of course, if you set the “acceptable” risk level too high, the government can step in.
Determining the risk level and the requisite safety solution
There’s a quantitative process for interpreting the risk level of a manufacturing solution. The calculations take into account the severity of possible injury and the frequency of exposure to hazardous machine motion. After you determine the risk level, it will dictate the type of safety controls that you need to implement.
Performance Level e (PLe) – also known as Safety Category Level 4 – constitutes the highest level of risk. This is a machine that has a high likelihood of severely injuring, or possibly killing, an operator if something goes wrong. Given such serious hazards, it’s crucial to ensure that it’s impossible for a single problem to cause a loss of safety functionality.
It’s important to note that each machine is unique and needs to be treated as such. Manufacturers must review the residual risk set forth by the assessment of each machine and identify whether that residual risk is tolerable. If not, then additional steps need to be taken in the risk recommendation process that reduce the risk to a tolerable level.
Balancing safety needs with costs and the impact on production
When Omron engineers perform a risk assessment and present a solution, they’ll be able to suggest ways to make the system compliant and bring its risk down to a certain level. Depending on the characteristics of the facility, it may be extremely complicated and/or expensive to achieve the lowest category of risk.
For example, if a company hires a lumberjack to use a chain saw, there’s lots of inherent risk there. It may be possible to automate the lumberjack’s tasks so that there’s no longer a person performing this dangerous activity. Although this would make the operations much safer, it’s also a million-dollar solution that might put the company out of business.
Interested in making sure that your machines are properly safeguarded? Get in touch with us about a machine safety risk assessment.