As early as the 1980s, Lebanese scientists discovered that sunlight can disinfect water. This revolutionary discovery, however, did not receive the attention it deserved, and systematic scientific studies and adaptations to the user’s needs were not done. In the 1990s, the Swiss Federal Institute of Aquatic Sciences and Technology (Eawag) decided to investigate this discovery to create a safe, simple method that could be used in developing countries.

An interdisciplinary research team, consisting of microbiologists, virologists, engineers and drinking water specialists, developed the SODIS method, which requires only PET bottles and sunlight. Eawag tested this method in the laboratory and under field conditions in developing countries to evaluate its effectiveness and applicability. These tests showed that the SODIS method was effective, user-friendly, and affordable.

Famous research establishments, such as the Royal College of Surgeons, Ireland, and the University of Uppsala, Sweden, also studied the SODIS method. Their studies confirmed that the method does kill germs and has a positive effect on people's health. Eawag also carried out research projects that dealt with microbiology and that examined health aspects, education strategies and PET bottles.

To ensure that the SODIS method is made available to the people who need it most, Eawag started implementing projects in more than 25 developing countries in 2001. In 2011, Eawag und the Swiss NGO Helvetas Swiss Intercooperation entered into a partnership with the goal to jointly promote the SODIS method worldwide. In the context of this partnership, various projects supporting the promotion of household water treatment, including the SODIS method, are being carried out by Helvetas.

© SODIS 2019
Last update: 19.12.2014