Question C-22: What is the difference between RESNA WC19 and ISO 7176-19? If I comply with the requirements of one of these standards, do I comply with the other one?
A wheelchair can comply with one or both standards. Although the test procedures are similar, there are some key differences in performance requirements and overall scopes of the standards. We have a table describing differences between WC19 and the 2008 and proposed 2019 versions.
One key difference is that a WC19 wheelchair is subjected to a higher load during impact testing because it is tested with a crashworthy, wheelchair-anchored lap belt. This delivers added load to the wheelchair frame and requires a higher level of baseline strength. WC19 wheelchairs can be used with this crashworthy belt attached but are most often used with a seatbelt system that is fully anchored to the vehicle. ISO 7176-19 allows but does not require wheelchairs with crashworthy, vehicle-anchored lap belts.
In addition, WC19 wheelchairs must be evaluated for lateral stability using a tip test, while there is no requirement for this in ISO 7176-19.
Another difference is in the method for conducting the frontal impact test. WC19 specifies requires the use of a surrogate four-point strap-type tiedown to secure the wheelchair on the sled platform. By comparison, ISO 7176-19 requires that the wheelchair be secured by a four-point strap-type tiedown that complies with the frontal impact test of ISO 10542, which can be either a commercial tiedown or the surrogate tiedown.