Principal differences between the standard of the Personal Protective Armor Association (PPAA) and the standard of the National Institute of Justice (NIJ) are the PPAA's attempts to lower the requirements -- by averaging blunt trauma measurements, lowering the threat from all ammunition by spreading the velocities, allowing lower velocity passes, using test ammunition that deforms more easily, making waterproofing optional, and prescribing labels that not only do not list the ballistic threats, but appear to place the liability for selection on the individual wearer or his or her department. This serves to modify or eliminate many of those requirements and test methods of the NIJ standard, thus placing police officers' lives in jeopardy.