Product Design – Avoiding Unintended Safety Consequences

Who is it?

 The Maze, Safety Pin, Design icons

Think about who you are designing your products for

As a product designer, manufacturer or importer of consumer products, you’re likely thinking about the intended user of whatever it is that you’re creating or selling.

However, as you’re about to learn, you also need to consider who else might be exposed to it – sometimes causing unintended (and rather harmful) consequences.

The Exercise Bike Story

Not that long ago, all exercise bikes looked like this: exercise bike old styleThis style worked fine for the user – the pedals went around, the seat was comfortable, and it effectively simulated riding a bicycle outdoors while allowing you to remain in the comfort of your living room.

But, the important question to ask is: Who else might have been in that living room?

Oh No!

baby touches you

With these old style exercise bikes, toddlers were attracted to the moving parts.

So, when mum and dad were nowhere around and an older brother or sister was pedalling away, the toddler would innocently and inquisitively reach toward the moving wheel, crushing their young fingers to pieces.

Injuries like this often require multiple operations to repair the damage as the child grows, meaning that one simple incident has effects that last for long periods, if not a lifetime. (If you’d like to see what a badly damaged finger looks like, here is the link: http://traumahand.blogspot.com.au/2012/06/finger-tip-amputations-ring-and-middle.html. However, if you’d rather not, I don’t blame you.)

Back in the early 1990s, the mother of one such injured toddler in Adelaide was curious if this had happened to others. She asked he hospital to check their records and was surprised to find that there were several similar reported incidents.

This revelation prompted a check of other Australian hospital data, which also revealed a significant number of these same types of injuries across the region.

Exercise bike safety unguarded spokes

What Went Wrong?

While designers of early exercise bikes probably considered the safety of the intended users, they failed to think beyond that. Essentially, they neglected to ascertain the environment, specifically:

  • where the product was likely to be used, and
  • who else might be exposed.

Think Beyond User Design

For reasons like these, product designers need to think about the intended users as well as whoever else might be exposed to the product.

You need to identify the possible hazards that can result from intended use and from misuse, which is often foreseeable. In the exercise bike example, an adult riding the bike for fitness and weight loss is the intended user.

However, children playing on them when their parents aren’t in the room is unintended use. And, although the children on the bikes might be at some risk, any toddler in the room is even more vulnerable to potential hazards.

So, what is the solution?

Risk Evaluation

Performing exposure analysis would quickly and easily identify and characterise the intended users, potential users, and even unintended users.

Risk evaluation assesses the environment that the product is used in and considers potential injury scenarios.

Guidance on risk evaluation (including hazard identification and exposure analysis) is available in the international standard ISO 10377 – Consumer product safety – Guidelines for suppliers.

Creating Standards

Once the problem with the exercise bikes was recognised, people rallied around and created a written standard (see our e-book on influencing product safety policy).

Australian Standard 4092:1993 Exercise Cycles – Safety Requirements sets out ways to make exercise bikes safe for homes with young children.

Standards are a valuable resource for designers. They’re written to address problems that have been identified and they set performance and design specifications against which new products can be objectively assessed.

Australian Standard 4092 was made mandatory in 1994 and, since that time, exercise bike design has been revolutionised.

The market responded and enclosed all moving parts that could trap young fingers.

I often cite this standard as the most successful consumer product regulatory measure that Australia has introduced as it certainly demonstrates the power and effectiveness of hazard elimination through design. Exercise BikeExercise cycles are still familiar items in gyms – and in our homes – except now they are much safer for our children.

What About the Second-Hand Market?

After this standard had been in place for a while, I did a talkback on Melbourne radio. A man rang to say his 18-month old grandson had lost a finger from an exercise bike incident. He asked why the bike hadn’t been recalled. I explained that governments do not usually seek a recall for problems that occur across a whole product category. Instead, they educate and call on consumers to manage the hazards until compliant products are available.

I still own (and use) an old style exercise bike that I bought before the standard came in. I guess I haven’t ridden it as often as I should have, since it’s now more than 20 years old and still going strong! But, as I do with my old bike, the simplest way to stop kids from using it and putting toddlers at risk is to use a bike lock. Exercise bike with lock highlighted

The Lesson Learned

Unfortunately, lots of children had their fingers badly damaged, sometimes permanently, before the change was made.

And when the problem was first identified and addressed, manufacturers had to re-design, re-tool and re-package their products – all at a big cost.

That’s why it is so critical at the start to think about where your product will be used and who might be exposed. If you’re designing consumer goods, make user and environment assessment a priority.

* A Footnote

When the finger injury issue was being researched, a hazard to intended users was also revealed. A few reports found that some overweight users had broken the seat and sustained some unfortunate injuries on the seat stem.

It’s foreseeable, even likely, that overweight people would use exercise bikes especially in the privacy of their own home. So, some exercise bikes weren’t even well-designed for their intended users.