Nearly 80% of incidents involving electric bidet toilet seats ¡ª including fires ¡ª over the past decade involved products more than 10 years old, according to a report by the National Institute of Technology and Evaluation (NITE), prompting an advisory for users to conduct safety checks on a regular basis.

Of the 69 cases of damage and injuries reported to NITE, which assesses product safety and quality standards, a total of 54 ¡ª or 78% ¡ª involved products manufactured 10 years before the incidents or earlier.

While 40 cases resulted in only damage to the toilet seat warmers, there were eight incidents in which users were injured, including suffering serious burns caused by appliances abnormally overheating. Additionally, there were 15 cases in which electric bidet toilet seats caught fire.

In one case at a Tokyo home in 2022, the toilet seat caught fire, possibly due to abnormal overheating of the circuit board attached to the motor that operated the cleaning nozzle. The cleaning nozzle had been broken and was left in its extended state before the incident, according to the NITE report released in July.

In a 2017 incident at a store in Nagano Prefecture, a toilet seat caught fire, which NITE attributed to the possibility of a store employee cleaning the appliance with a highly acidic detergent instead of using a neutral cleaning agent. Repeated pressure from the seat being used for a while could have also caused its heater wire to break and cause the fire, it said.

While electric bidet toilet seats are often used over extended periods, NITE emphasizes that they have a limited lifespan. It recommends users to apply detergent to a piece of cloth and use it to wipe down the appliance instead of spraying cleaning agents directly onto the seat when cleaning it.

The institution also advises consumers to immediately shut off the water, unplug the appliance and consult the retailer or manufacturer if they notice water leakage, a burnt smell, abnormal overheating or cracks in its control panel.

More than 50 years have passed since domestically produced bidet toilets were first introduced in 1967.

About 82% of all toilets in Japan have electric bidet toilet seats, with nearly all homes with flushing toilets having them installed, according to NITE.