An Indian social reformer who has worked to end an age-old stigma associated with a lack of proper toilets says he is confident that his design can keep over two billion people from suffering from poor sanitation around the world.

Bindeshwar Pathak, founder of Sulabh International, has worked for 50 years to solve sanitation problems in India. He invented a composting flush toilet that his nongovernmental organization has installed in 1.5 million homes.

The Indian government has introduced 60 million toilets of a similar design throughout the country. The government’s goal is 100% access to toilets by 2019, and Pathak said it already has achieved 85%.

But his ambitions are not confined to India—he is helping solve similar problems in country in Africa, Asia and Latin America where two billion people lack access to safe and hygienic toilets.

India's lack of proper sanitation has a long and deep connection with its caste system. The former "untouchable" caste once removed human waste by hand and suffered the stigma associated with this work.

Afghanistan, Bangladesh, China, South Africa and Ghana have also adopted the Sulabh design. However, he said there is also demand for inexpensive waste disposal in developed countries, as people in some areas still use septic tanks.

During a recent visit to the U.S., Pathak said he was asked to export his technology to build toilets in American rural areas where sewage systems are not in use. He said he has also discussed with companies in Japan, known for its high-tech toilets, for building cheap models the Sulabh way. 

While these countries have the technology to install modern flush toilets, the costs tend to be high. In an extreme example, one unit can cost $9000 in Tokyo, compared with only $20 for a Sulabh toilet in India, he said.