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A New System of Waterless Bio Toilet “Bio-Lux”

A New System of Waterless Bio Toilet “Bio-Lux”

Seiwa Denko Co., Ltd.

Bio-toilet with a New Method
“Bio-Lux”: Treatment with Sawdust
That Enables No Use of Water

Seiwa-Denko develops and manufactures the bio-toilet that uses neither water nor special bacteria, and treats human waste with ordinary sawdust. Our policy is that "when one bio-toilet is installed, the water will be clean", both domestically and internationally. We are working on the promotion of toilets.

Our bio toilet called “Bio-Lux”, eliminates human waste by "evaporating and decomposing" it with sawdust filled in the toilet. What remains in sawdust is an inorganic component that is neither evaporated nor decomposed, and it can be used as an organic fertilizer.  

Fig. 1 Product photo and layout of “Bio-Lux”

Fig. 2 The image of sawdust used in “Bio-Lux”

Major Features and Advantages

  • No use of water
  • Use ordinary sawdust instead of water
  • No special bacteria needed
  • Sawdust needs to be replaced only about 3 times a year
  • Sawdust becomes organic fertilizer after used
  • Various types are developed, divided by processing capacity
  • Own intellectual property etc.

Technology Data

Possible applications

We propose that our products can solve the wastewater issue for people under the condition of living in areas not installed with a sewage system by installing Bio-toilet “Bio-Lux” and water purifying device. Human waste can be processed by Bio-toilet “Bio-Lux”, which evaporates and decomposes human waste and toilet paper with sawdust, and other wastewater can be proceed by water purifying device with Bincho-charcoal. 
By separating human waste from sewage, it leads to less burden of sewage and it makes easy to process. (see Fig. 3)

                                                         Fig. 3 Application of bio toilets to household

New purification device mentioned above is called “Bio-lux Water”. It can treat wastewater other than from a toilet by the filtration with charcoal, and the purified water is the same level of rainwater. (see Fig. 4 and 5)

                                                         Fig. 4 New purification device “Bio-Lux Water”

                                                     Fig. 5 Verification result of new purification device

Competitive advantage

【Efficacy of sawdust as treating agent】
Sawdust has wide surface are and microscopic holes, which is suited for biological decomposition. When human excreta and urine are mixed with sawdust, moisture evaporation occurs first and restrain the generation of offensive odor. (see Fig. 6)

                                              Fig. 6 Principle of decomposition and evaporation on sawdust

【Comparison with flushing toilet on initial/operating cost】
To operate flushing toilets, it needs to be under the condition of infrastructure development such as sewage, sewage treatment plants, and water resources. Therefore, it involves enormous cost and time, and the initial cost is covered by government or municipalities. Additionally, individuals pay a construction fee for draining wastewater to public sewage treatment from flushing toilets. On the other hand, since “Bio-Lux” does not need an infrastructure development, it costs only itself and installation fee to commence operating. Due to the different conditions, it is difficult to compare in cost with accurate numbers. However, by concerning of infrastructure development and operating cost, we could say that “Bio-Lux” has a high-cost performance.


There are several types of Bio-Lux products divided by processing capacity, therefore it is available to choose the type and quantity depending on the place to install. (see Fig. 7)

                                            Fig. 7 Specification and layout for installation of “Bio-Lux”

Technical maturity / Past record of introduction

We have been selling more than 3,600 units of Bio-toilet “Bio-Lux” and achieved many intellectual property rights since we started the development of Bio-toilet “Bio-Lux” in 1996 and keep improving until the present day.
We have done demonstration projects of Bio-toilet in Vietnam with the support from Japan International Cooperation Agency (JICA) and the Japan External Trade Organization (JETRO). It is installed on trains and ships as well. It has a good reputation as a public toilet at sightseeing places.

Information on patent related to this technology

Japan patent: No.6186095
US patent: No.10130222
China: ZL201810182716.6
Vietnam: SO 23800
India: No. 395126

Company Data

Name Seiwa Denko Co., Ltd.
Address 3-2, kougyo-Danchi 1-Jo 1-Chome, Asahikawa-shi,
Hokkaido, 078-8231 Japan
Capital 50 million JPY (as of May 2022)
Contact person

TEL: +81-166-39-7611
Corporate website: https://seiwa–

Number of employees 10 (as of May 2022)
Date of company foundation 17, October, 1974
The type of business

Manufacture/sale sustainable products and wholesale business in electric appliances


International operation

Number of employees for international operation 
Overseas offices
City, Country Name of Company
(if applicable)

Modality of business transaction

Export of product
We would like local people to realize the quality of our products first, and we convince them of the practicality of our toilet.

Licensing of patent
In the event local government or local authority come visit to inspect our bio-toilet and admit that it can meet their policy, manufacture/sale at there would be possible. At the point, we would like to transfer the patent and manufacture/sale at there.


We produce the bio toilets helpful in the event of a disaster.

Application of human waste decomposition to the processing of animal corpse.

Contact Person(s)

Ms. Noa YAMADAE-mail:

*Please mention that you saw UNIDO's website when making the first contact with the company.

Registered Category

  • Environmental Technologies : Pollution Prevention and Control
  • Human Health Technologies : Public health