Seoul Metro, the operator of subway lines 1 to 8, announced Tuesday that it will replace all fabric seats on its subway trains with reinforced plastic chairs by 2029 to keep the trains clean from bedbugs and other pollutants.

According to Seoul Metro, fabric chairs account for 54 percent, or 1,955 subway cars of all seats on Seoul’s subway trains. On the other hand, reinforced plastic chairs account for 29 percent of Seoul’s subway trains, while stainless steel seats account for 17 percent.

Seoul Metro added that it will first begin to replace all fabric seats on Line No. 3’s 340 subway cars, which are due for replacement, with reinforced plastic chairs. To replace the seats on Line No. 3’s trains, the subway operator expects to use 4.5 billion won ($3.3 million) of its budget. Fabric seats in other subway trains will be switched to reinforced plastic by 2029.

Seoul Metro’s plan to replace subway seats comes amid a recent rise in concern about bedbugs being found inside subway cars. From October 2023 to March this year, Seoul Metro stated that it received 66 reports regarding bedbugs, although none have been verified.

According to Seoul Metro, the current condition of Seoul’s subways is not suitable for bedbugs to live in.

“Bedbugs are insects that hide in crevices during the day and become more active during the night and prefer humid, dark and warm places,” said a Seoul Metro official. “The basic structure of a subway seat is made of metal and subway cars are stored outdoors when they are not being operated. As a result, Seoul’s subway cars are an inhospitable environment for bedbugs to thrive in.”

Subway trains are constantly vibrating and are a bright environment, making it difficult for bedbugs to thrive when the subways are in operation, according to pest experts with whom Seoul Metro consulted.

However, Seoul Metro added that these facts do not rule out the possibility of bedbugs being brought into the subway through passengers’ clothing and baggage, which prompted the operator to replace all fabric seats to ensure a cleaner subway environment.

Meanwhile, Seoul Metro regularly carries out chemical pest control through high-temperature steam cleaning to get rid of possible bedbugs and other pests. Additionally, the subway operator also works with an extermination company once a month to detect the presence of bedbugs inside the subway cars.