Starting Thursday, passengers departing through Incheon International Airport wearing shoes with heels taller than 3.5 centimeters will be required to remove their shoes during the security screening process.

Previously, such a rule was only enforced in "suspicious" cases, but the updated regulation now applies it uniformly.

The enhanced shoe screening measures are being implemented at both Terminal 1 and Terminal 2 and apply to all passengers using the cylindrical security scanners.

"This isn't seen as a major change to the security team, but rather a clarification of previously unclear guidelines about shoe removal during screenings," an Incheon Airport official explained. "It is unrelated to the country's current political climate and was planned for implementation well in advance," the official added.

On the first day of enforcement, airport authorities analyzed the number of shoe screenings conducted across all departure zones between 7 a.m. and 9 a.m., to minimize passenger inconvenience in the future.

The cylindrical security scanner was first introduced at Terminal 2 in 2017, and Incheon Airport now operates 41 of these scanners, which make up 70 percent of its 58 security screening units. The remaining 17 units are traditional walk-through door-style scanners.

One of the advantages of the cylindrical scanner is its speed, with an average scanning time of under 25 seconds per passenger. Door scanner screening takes longer overall because it requires a separate check by staff afterward.

However, agencies like the National Intelligence Service and the police have raised concerns about its limited effectiveness in detecting items below the ankle. They pointed out that contraband like drugs or ceramic weapons hidden in shoe soles or heels might go undetected. The enhanced shoe screening policy is expected to resolve these concerns.

Travelers wearing shoes with heels over 3.5 cm, including platform slippers, winter boots, or rain boots, must remove them for the cylindrical scanner, while low-heeled shoes, sneakers and rubber slippers are exempt. Passengers using traditional door-style scanners can continue to wear their shoes during the process.