A screener should not be doing screening for more than

According to the guidelines prescribed by the Bureau of Civil Aviation Security (BCAS) in India and international standards set by the International Civil Aviation Organization (ICAO), a screener must not perform continuous X-ray monitor screening for more than 20 minutes. This limit is strictly enforced to prevent "vigilance decrement," which is the decline in alertness and the ability to detect prohibited items due to eye strain and mental fatigue. After a 20-minute session, the screener must be rotated to other duties (such as physical frisking or queue management) for at least 40 minutes before returning to the X-ray monitor. This rotation ensures that security personnel maintain the high level of concentration required to identify potential threats effectively.