Star Engineering Co., Ltd., tatiisu Ltd. and Nakazima Kogeisha Inc.
have been collaborating to create a compost toilet
that changes people’s perceptions of sanitary objects.

The project was originally initiated in order to solve the problem
in care homes where one has to have a toilet in the bedroom.
Portable toilets often release offensive odours and are aesthetically displeasing.

In 1991, Star Engineering started developing
and trialling household food waste disposal units, and created “BioClean”,
a compost bin that decomposes more than 85% of food waste
into water and carbon dioxide within 24 hours.
The remaining 15% can be used as high quality compost.

This success led Star Engineering to wonder if "BioClean"
could also help to decompose human waste quickly.
The simple idea set off another round of research to look at
the various problems of conventional portable toilet design.

Star Engineering’s compost toilet Biolet has excellent performance
in efficiently decomposing and reducing the volume of human waste.
It decomposes and processes human waste in a short time
by activating the decomposing microorganisms in the Acidulo base material.

The system is waterless and does not require pumping or purification of sewage,
which is why Biolet is the first choice for mountain parks,
small islands, event and construction sites, emergency shelters, etc.

It was clear however that a more refined design would be necessary
in order for a composting toilet to be accepted in a domestic setting.
Tatiisu took on the role of designer for this project.
Using the same system as Biolet and adding much more sophisticated details
that could only be crafted by
the highly skilled woodworking manufacturer Nakazima Kogeisha,
the collaboration made it possible to create
a compost toilet that is also a beautiful piece of furniture.

The Torch toilet will change people’s perception
and open up new possibilities for composting products.

The Torch series will keep growing.