Simply pressing the nose ring towards the injection point activates some injectors. The protective cap serves as the major safeguard in these designs. Other designs make use of a nail-gun-like safety mechanism: Pushing the trigger button on the device's back end while simultaneously applying pressure to the injection site and the nose ring triggers the injection. Waste management personnel should be aware that used Auto-Injectors could be a biohazard because they include a hypodermic needle. Thus, the protective cap is made to adequately contain sharps waste after disposal in addition to safeguarding the medicine and maintaining needle sterility.