History of the Bidet Toilet Seat

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Have you always wondered why Japan has these amazing toilets?  It almost seems like all the toilets in Japan can wash your bottom, play some music, or keep your bottom warm with heated seats.  But this wasn’t always the case.  In fact, the sitting toilet wasn’t even a common thing until the late 1970s.  In this post we’ll look at the history of toilets in Japan, including how the bidet toilet seat was invented.  We think it’s a very special story, and for anyone who is trying to invent something, there are some good lessons to be learned.

13th – 19th century

Toilets weren’t really a thing that common folks used until the 13th century in Japan.  Before then, the only people who used toilets were the aristocrats in Kyoto.  They used “state-of-the-art” wooden boxes that were imported from China.  Basically these toilets had a container that slides out, not unlike a wooden coffee mill.  Everyone else simply defecated on the side of the road.  As you can imagine, diseases and deaths were widespread.  But in the 13th century, as people were generally better nourished, the feces of human beings began to be used for farming.  Bucket style toilets were developed to gather the feces to use as manure.  This yielded bigger crops.  By the 17th century, gathering feces was big business.  As people lived in communal housing, landlords collected waste from toilets in the household and sold it to farmers.  There were even brokers to negotiate the sales.

Gradually sanitation improved.  Meanwhile, in the West, toilets were made out of ceramic, which were much easier to clean than wood.  Realizing this, Japan began to changed its bucket style wooden toilets to bucket style ceramic toilets.  The first one was invented in the mid 19th century.  Like most things, they were first used by the wealthy and featured decorative patterns.  Industrialization brought forth a white bucket style ceramic toilet (squat toilet), and was widely used in Japan until WW2.

1950s – Today

Beginning in the 1950s, with the creation of chemical fertilizers, human feces were no longer used in agriculture.  Japan began a period of rapid economic growth and saw large populations of people moving to urban areas.  This led to the construction of underground sewage.  And because there was little space in urban houses, households began to adopt the use of western style toilets (in the past, households had both the urinal and squat toilet).  In 1977, shipments of western style toilets surpassed those of Japanese style squat toilets.

Toto, the Japanese toilet company based in Kitakyushu, grew rapidly from the 1960s thanks to the housing boom in urban areas.  Today, the company makes about 60% of all the toilets in Japan, and is the largest toilet manufacturer in the world.  In 1978, they decided to embark on another project.  Having discovered that many people suffering from hemorrhoids take hot water to the toilet to wash themselves, they wanted to develop a toilet that could wash your bottom.  At the time, there was already a medical device that was being sold.  But the water angle and the temperature were unpredictable.  People were complaining about it, but Toto realized there was great demand for such a product.

To develop this product, they first had to figure out the optimal temperature for the water.  And the only way to do this is trial and error!  At first, the development team asked for volunteers in the company to sit on the toilet so they could try out different temperatures.  But as you can imagine, no one wants to be the guinea pig!  So the development team was left to do this by themselves.  They would sit on the toilet for many hours a day, and often they would burn their bottoms!  Others in the company started feeling bad for them, and couldn’t watch any further.  So they joined in.  At the end of the experiments, they collected data from 300 men and women and determined that the optimal temperature for the water spray would be 38 degrees Celsius, give or take 2 degrees.

The next challenge was figuring out how to hit the mark so that water doesn’t spray all over the place.  They determined that the best way was to get the water as close to the body as possible, but how?  Where would the water come from?  They went through another series of trial and error, and failed to come up with anything substantial, until one day, a team member noticed the retractable radio antenna of cars and it gave them the idea that a nozzle spray could extend and retract.  After lots of testing, they found the perfect angle of the spray at 43 degrees.

The final challenge was to figure out how to heat the water, and keep it as close to 38 degrees as possible.  This is the most tricky part because water and electricity do not mix.  In fact, the development team had so much trouble with this part that the project was at a standstill for some time.  But as we know, the bidet toilet seat exists today so they must have had a breakthrough.  That breakthrough came when a team member noticed that even during rain, traffic light signals still work.  They discovered that it was because the circuitry of traffic lights are covered in a unique resin to prevent short circuiting.  So with this new discovery, they produced a circuit board that was treated with resin.  In 1980, two years after the project began, the toilet seat spraying warm water was put on the market.  Word spread quickly and production skyrocketed to 100,000 units a year later.  Of course, the original toilet seat bidet had the single function of spraying warm water, but nowadays, it has many more functions like a seat warmer and a sound concealer.

One final (quick) story: Yes, we said sound concealer.  If you’ve been to Japan you’ve probably noticed a musical note on the control panel of the toilet, wondering what that is.  Japan actually has a long history of covering “embarrassing” sounds while using the toilet, which dates back to the Edo period.  When the feudal lord visited temples and used the toilet, his servants would conceal the sound by turning on the tap of a pot.  Nowadays, it’s Japanese women who mainly wish to conceal sounds.  To conceal sounds, they may flush an average of 2.5 times each time they use the toilet, or 32.5L of water each time.  So with the sound button, it cuts down the use of water significantly.

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