Generally 24 hours.
Aseptic technique is a series of operational techniques to keep sterile items and sterile areas free from contamination and to prevent the invasion of pathogenic microorganisms into the human body during medical care operations.
Basic operation
Wearing a work cap prevents dust and microorganisms from falling from the hair and causing contamination. When caring for infectious patients, you can also protect yourself, the work cap is the right size, hair all stuffed into the cap, not exposed. Replacement twice a week, operating room or strict isolation unit, should be replaced every time.
Wearing a mask can prevent droplet contamination of sterile items. Masks should cover the mouth and nose, the ligature elasticity is appropriate, not to touch with contaminated hands. When not in use should not be hung in front of the chest, should be clean face inward folded, into a clean coat pocket. Once the mask is wet, the germs are easy to invade, should be replaced in time.
Baidu Encyclopedia - Aseptic Technology