From the information I found a significant risk device is one that can present a possibility to affect the health, safety or well-being of an individual. These are often class II or III devices such as sutures, pacemakers and various implants. Non-Significant risk devices, however, do not have the possibility of causing a life- threatening risk to the individual. These can include catheters or contact lenses.

Source: http://www.childrenshospital.org/~/media/…/SR%20or%20NSR%20Device.ashx