Expired Band-Aids can cause the following situations: 1. The use of expired Band-Aids can lead to wound infection, because Band-Aids are valid and sterile within the validity period, and the anti-bacterial drugs on the surface of Band-Aids are effective within the validity period, so the use of such Band-Aids can effectively sterilize and reduce inflammation. The use of expired band-aids not only due to the band-aid itself may be contaminated by bacteria leading to wound infection, expired band-aid surface drugs will also fail, can not play the role of sterilization. 2, the use of band-aids after the expiration date, resulting in wound hemostasis function decline, because one of the effects of band-aids is the surface layer of hemostatic drugs, to wound bleeding and achieve the effect of hemostasis. Once the band-aid expires, this effect will fail and cannot play an effective role in stopping bleeding.