Machinery Safety 101 - Safe designs for safe workplaces
Skip to content

The Myth of Common Sense

2014 September 2
Comments Off
by Doug Nix

Analysis TeamWay back in 2007, I posted a podcast episode where I discussed the idea of “common sense”. When teaching risk assessment, one of the old saws that often comes up in the group work is “common sense”. You know how this goes, and you may have used this argument yourself, once or twice. I’ve heard this kind of discussion in far too many risk assessment meetings:

Sally: That whirling whatsis is really dangerous. The edges are so sharp, I bet it would take your whole arm off if you reached into it.

Devon: Come on, Sally, nobody would ever do that! It’s common sense! You can easily see the whatsis whirling around. Why would anyone reach in there?

Christina: Devon, this new model is designed for four times higher whirling rate. I doubt you could see it moving, especially considering the lighting in that area.

Devon: I just don’t see why we need extra guarding in that area when everybody knows the whatsis is dangerous…

So here is the problem as I see it: Common sense is based on the idea that everyone in a group or company has a common set of knowledge about what is dangerous and what is not. I can agree that, for some very common things like kitchen knives or scissors, that may be true, but we also still cut ourselves with these tools quite often. As soon as you step away from something that is absolutely everywhere, the idea of common sense goes out the window. Mark Twain wrote, “Common sense is very uncommon”, and he was right. Most industrial workplaces today include all kinds of technologies that people rarely encounter in their daily lives, outside of  the workplace. Lasers, UV cure adhesives, nano-particle materials, and even more common things like electricity are not encompassed in the average person’s common knowledge. “Common sense” might have been reasonable in agrarian times when most people were born, grew up, aged and died on the same plot of land with family all around, but it just doesn’t make sense today. Common sense is limited to the individual, and is defined by that person’s training  and life experience. Each and every one of us has a different knowledge base, with some similarities, but not enough for us to rely upon for safety. Since people are not labeled with the content of their common knowledge, there is no way for a machine designer, a supervisor, or anyone else to judge whether they will have the necessary “common sense” to avoid injury in any given set of hazardous circumstances.

The idea of common sense is dangerous. It leads decision makers to a false sense of security about what the ubiquitous “user” will know, and how they will behave. If there is one thing we know about people, it’s that people are unpredictable, even more so when under stress. It can also lead to blaming the victim; consider a statement like, “I can’t understand why Bill got hurt, it’s just common sense. He should have known better…” The concept of common sense needs to be banished, at least when talking about workplace safety and machinery safety. If hazards are guarded, risks are reduced. End of story.

So here’s my challenge to you: The next time someone brings up the idea of common sense as a reason to avoid implementing some kind of safeguarding, run a little experiment. Go out in the hallway with a picture of the hazard and ask 10 people if they see anything dangerous in the picture, and what they would recommend. Try to pick from as wide a group of “test subjects” as possible to get a good sampling of people’s common sense. Then take the results back to the risk assessment table. I think you’ll be amazed at how uncommon common sense really is.

Why should you get involved in Standards Development?

2014 July 15
Comments Off
by Doug Nix

Committee groupIt’s now been more than 30 years since I first learned about standards, in the form of the Ontario Electrical Code. I was studying electricity and electronics in high school, and Steve Struk, the Electricity Teacher at Erindale Secondary School in Mississauga, introduced us to the rules. My first encounter with international standards was 25 years ago, when I was tasked with doing some environmental stress testing using a thermal, humidity and vibration chamber at Hammond Manufacturing in Guelph. Standards were, and are, an important part of engineering and technology, and they play increasingly important roles in business and occupational health and safety. Writing standards takes time. Lots of time. That time has to be provided by interested people and organizations who recognize the value that standards bring to their work and their businesses. Most people involved in standards committees are “paid volunteers”, meaning that they are volunteering their time, but their employers are paying them for the time they spend engaged in standards work. Some, like me, are true volunteers, where the time spent on standards work is given without any compensation except the knowledge that we are contributing some small part to making Canada a better place to live and work.

So why should you get involved in standards work? A recent SCC communiqué said it very well:

“SCC’s membership in the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) provides Canadian business, government and consumer stakeholders with the opportunity to sit at the table of global experts making the rules that will then dictate the global trade agenda within their field. As a member of a committee developing an international standard, Canada becomes part of a community of national experts creating the standard they need, and can benefit greatly through greater involvement in the development process.

As a member on a technical committee at ISO or IEC, a business can influence the future of its market, get early access to cutting edge information and define its competitive environment internationally. Simply put: participation in international standards development provides Canadians with an opportunity to influence a document that could affect their lives or business in the future.”

Getting involved in standards writing is rewarding, challenging, work. Getting involved gives you a chance to contribute your knowledge and expertise to Canada’s future, and provides an “…opportunity to influence a document that could affect their lives or business in the future.”

Get involved. Contribute. It’s worth it!

Digiprove sealCopyright secured by Digiprove © 2014
Acknowledgements: Standards Council of Canada
Some Rights Reserved

Risk Assessment Blunders

2014 June 26
Comments Off
by Doug Nix

Analysis TeamUpdated 7-Jul-2014

Recently I read a blog post written by David Cant, called, “Are You Making These Risk Assessment Blunders?“. Writing in the UK, Mr. Cant spoke to some of the common kinds of problems that can occur when employers conduct risk assessments. Many his points are equally applicable to machine building:

  1. No Risk Assessment – This seems self evident, since you can’t work to control what you don’t know exists. Unfortunately, some liability lawyers have advised clients NOT to conduct risk assessments, on the basis that you can’t be blamed for something you knew nothing about. This position is changing, since risk assessment has become a fundamental piece of the machinery design process and is included in US, Canadian, International, EU, and Australian standards to name a few. What remains as a liability are poorly done risk assessments, and those can certainly hurt a company in a liability case. See Point 3.
  2. Not Properly Identifying Hazards – This is another big one. Machine builders sometimes fail to understand the hazards that are incorporated into their machinery, especially in the case of system integrators. Identification is the first step, analysis is the second step. Once the hazard has been identified, the assessors must analyze the hazard to understand the magnitude of injury that can occur, e.g., a paper cut, hearing loss, permanent musculoskeletal disorder, fatality, etc.
  3. Creating an inadequate risk assessment – If you “phone it in”, any knowledgable person will be able to see that, and you can be sure that prosecutors will bring that to the attention of the court! Any claim that is made will be refuted by a knowledgable person hired by the prosecution.
  4. Assuming Safety Because You Have a Document – A risk assessment report never protected anyone from harm. Actions based on the report are what protect people from harm. Simply completing a risk assessment and sticking the report in the design file fixes nothing, and going back to the liability discussion, will create problems when it becomes clear that a) You knew about the risks, b) You thought out mitigation measures for the risks, but c) You failed to act on your own recommendations.
  5. Not involving your employees – I would change this to read, “Not involving the customer or end user.” Getting a risk assessment done by an outside individual is likely going to result in a poor outcome, if that person does not work with the knowledgable people in your organization. If this is an internal risk assessment for a process used in-house, then you need the workers involved with the process to be part of the risk assessment team. You also need the process designers (electrical, mechanical, software, etc.). If this is a product development risk assessment, then you will need product designers, marketing or sales people, and end-users. In all cases you may also need outside experts to help with hazard analysis and mitigation, since you may not have the expertise in-house. A good example of this is the use of industrial lasers into processes.
  6. Assessing risk generically – this goes back to point 3 – a risk assessment has to relevant to the process, product or service that it describes. using a risk assessment developed by someone else for some other similar product, process or service limits your thinking to just what they decided was relevant. Better to start with a blank sheet, and only at the end look at other’s work to see if you may have missed anything they included.
  7. Doing the risk assessment after the machine has been designed, built and put into use – This is a common problem, and especially affects workplaces that buy off-the-shelf machinery and used machinery. Many machine builders are not familiar with risk assessment or the benefits to their products, their liability exposure, and their reputation in the marketplace, let alone the benefits to their customers. Conducting the risk assessment after the equipment is in use means that the first stage of the Hierarchy of Controls cannot be used. Since this is the only stage that can achieve 100% risk reduction, this is a HUGE loss. In addition, this means that any changes needed to mitigate risk require expensive changes when the machinery is already in production, compounding the expense with lost production. If you have no other option — for instance, you’ve taken over an existing business and no risk assessments have been done in the past, then late is better than never, but it should be a last resort and not the first choice. Special thanks to Douglas Florence for suggesting this added blunder!

All of this brings me to some important standards. The Canadian Standards Association released CSA Z1002, Occupational health and safety – Hazard identification and elimination and risk assessment and control, in 2012. This is a landmark standard, because it addresses workplace risk assessment. No other standards development organization has released anything quite like it. There are some innovative ideas in the standard, including the idea of “risk transfer.” This concept explains how risk is transferred from the developer or supplier of a product, process or service, called the “external context”, to the user organization, called the “internal context”, and then to the worker. At each transfer point, the risk should have been reduced so that the worker’s exposure is as low as possible, and certainly no higher than permitted by law.

In the machinery world, the “mother standard” is ISO 12100, Safety of machinery — General principles for design — Risk assessment and risk reduction. This standard affects many of the machinery safety standards developed worldwide, including CSA Z432 and the ANSI B11 standards, and is harmonized under the Machinery Directive as EN ISO 12100. This standard lays out the process for safe machine design and provides the framework for machinery risk assessment. A companion document, ISO/TR 14121-2, Safety of machinery — Risk assessment — Part 2: Practical guidance and examples of methods, provides guidance on how to conduct a risk assessment, and offers up some example tools that could be used for this purpose. In the US, ANSI publishes ANSI B11-TR3, Risk Assessment and Risk Reduction – A Guide to Estimate, Evaluate and Reduce Risks Associated with Machine Tools, providing solar guides to users of the B11 family of standards.

Need to know more? Contact me for information training and risk assessment work in your facility!


All original content on these pages is fingerprinted and certified by Digiprove
Optimization WordPress Plugins & Solutions by W3 EDGE