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PRINICIPLE 1
Provide stabilization
Principle
Prevent products from tipping over or falling on someone by adding stabilizing features or securing them to their surroundings.
Know your center of gravity
Toppling objects can cause injury as well as property damage. Consider the consequences of a parked motorcycle falling onto a bystander, a ladder falling sideways with a house painter aboard, and a chest of drawers pitching forward onto a toddler who is climbing it to fetch a toy (see Principle 63 - Childproof hazardous items). An object is naturally stable when its center of gravity is within its footprint rather than outside of it. Move the center of gravity beyond the footprint (i.e., beyond the area of support) and the result is instability plus the potential to tip over. It also helps to keep the center of gravity low so that applied forces, such as the centrifugal force acting on a riding lawnmower turning sharply, do not overcome the stabilizing forces.
The motorcycle is stable because the center of gravity is within the motorcycleâs footprint.
Tip-overs are no joke
Between 2000 and 2013, the US Consumer Product Safety Commission reported that product tip-overs and/or instability led to 430 deaths. They also reported that tip-overs caused an average of 38,000 injuries requiring emergency department visits per year during the period of 2011 to 2013. Most of those injuries (56%) were caused by furniture tip-overs. The most common injuries were contusions, abrasions, and internal organ damage. The most commonly injured body part was the head, followed by the legs, feet, and toes. Children between the ages of 1 month and 10 years accounted for 84% of the reported deaths.1
The motorcycle is unstable and prone to tipping over because the center of gravity is outside the motorcycleâs footprint.
Never go beyond your footprint
When you add a person into the mixâsuch as one standing on a stepladderâthe key is to keep the person reasonably centered within the footprint, rather than extending past it. In the case of stepladders, railings (see Principle 32 - Provide a handrail) help to do this as does making the steps narrower as the height increases. A crossbar-type of hand hold also encourages safe positioning.
Training wheels increase a bicycleâs footprint, which helps children keep their balance.
Stability improves as you enlarge an objectâs footprint without changing other physical variables (e.g., height, weight). That is why an office chair with a five-leg base is inherently more stable than one with a four-leg base.
To prevent tip-overs and still handle heavy loads, lift trucks and cranes have outriggers that extend to increase their footprints so that they remain under the entire apparatusâs center of gravity. Outriggers of a sort are also used to stabilize the top of some roofing ladders.
Cranes use extensions (outriggers) to increase the craneâs overall footprint and create added stability.
If you cannot keep an itemâs center of gravity within its footprint, or if forces might overturn the object, then some kind of retention or hold-down device might help. Common examples are brackets and tethers used to keep ovens and chests of drawers/bookshelves from toppling forward.
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PRINICIPLE 2
Make things easy to clean
Principle
Reusable products should be designed to facilitate easy and effective cleaning, sterilization, and/or disinfection.
Clean up nicely
Perhaps the biggest risk associated with things becoming dirty is exposure to chemical and/or biological agents. Thatâs why the food and medical industries have standards for cleanliness and even sterility.
Aside from causing contamination, filth can make labels and warnings illegible, make surfaces slippery when wet, and interfere with mechanical motion. For example, consider the following scenarios:
⢠A poorly located warning label could be obscured over time by soot from a machineâs exhaust pipe or by clippings from a mowerâs discharge chute.
⢠A greasy handle could lead someone to lose his or her grip while lifting a heavy object.
⢠Gears contaminated by dirt could fail to mesh properly, possibly leading to a dramatic mechanical failure or perhaps a motor overheating.
Accordingly, manufacturers of reusable devices should ensure that devices facilitate easy and effective cleaning, as well as any necessary disinfection or sterilization.
Toppings no one ordered
Easy cleaning should also be a priority in the food industry. Restaurants and establishments serving a high volume of customers typically use several devices to help expedite food prep in the kitchen. Unfortunately, some of these devices can have nooks and crannies that harbor guck and unwanted bacteria.
In July 2017, a McDonaldâs employee was fired after he tweeted pictures of an ice cream machine drip tray filled with mold (see image on left).1
FDA and reprocessing
Sobering to those who have undergone or will undergo a related examination, the US Food and Dru...
