Hygiene & Comfort Toilet Seat Washlet™ equipped with “ewater+” 2015-2017

Designers: Toto Ltd., Tokyo, Japan
Manufacturer: Toto Ltd., Tokyo, Japan

The objectives of this project are to improve the hygiene of the wash nozzle of the sanitary toilet seat Washlet™, which is designed to wash and keep your bottom clean after use, and to develop an innovative water quality improvement technology and washing system, which sanitizes and removes dirt on the toilet bowl. This Washlet™ is equipped with an unprecedented and innovative flushing system, featuring “a toilet seat that automatically cleans the toilet bowl” and “cleaning using electrolyzed water.”

One of the functions that maintained good hygiene on the conventional WashletTM was a self-cleaning function that used tap water to clean the nozzle before and after each use.

However, customers had concerns about the “contamination and cleanliness of the wash nozzle,” which were reflected in over 10 thousand responses to the “Customer Voices” questionnaires, especially worries about using the WashletTM of public toilets. Therefore, we started to develop a new cleaning function that can enhance the sanitation of the WashletTM nozzle.

We focused on “sanitizing water” and worked to create an original washing system that cleans the inside and outside of the nozzle using this method.

Although we already had technology that generates water containing “hypochlorous acid,” which has a sanitizing effect, by electrolyzing the chloride ion contained in tap water, we did not know which tap water had the required concentration for sanitization. Therefore, we analyzed the water quality at more than 200 locations in Japan and overseas to successfully develop “ewater+” (Japanese name : “Kirei-Jokinsui”), a water quality improvement technology that can obtain a sanitizing effect from any water source, regardless of soft or hard type.

We found that the sanitizing effects of ewater+ keep the WashletTM nozzle clean and control the development of bacteria that cause “circular stains” and “yellowing,” which are unpleasant inside of the toilet bowl. Spraying ewater+ after each use of the toilet can reduce such dirt, such as “grime” and “yellowing,” and enable environmentally-friendly cleaning (maintenance) that does not rely on synthetic chemical detergents.

Washlet™ equipped with “ewater⁺” will automatically clean the toilet every day, reducing the formation of heavy dirt and changing the style of toilet cleaning in daily life. Without relying on chemical synthetic detergents, which require care when handling (to remove risks), anyone from children to the elderly can safely and easily clean the toilet every day and maintain cleanliness. The sanitizing water can be generated from any water type. Since the sanitizing water turns into general water after use, it is environmentally-friendly and has fewer concerns about drainage, therefore, it can contribute to the reduction of the environmental load. Even when cleaning (maintaining) a toilet using synthetic chemical detergents, you can reduce their usage and the volume of waste water containing detergents.