The South Central Railway has decided to replace its existing toilets with new environment friendly bio-toilets. The toilets are jointly developed by Railway Research Design and Standard Organisation (RDSO) and Defence Research Development Establishment (DRDE). Around 48 bio-toilets were installed in two trains these January. Encouraged with the positive response, the SCR has decided to install 200 units in Padmavathi Express, Ajantha Express and all coaches of Hussain Sagar Express. SCR has already procured 80 of the 200 units, each costing `80, 000, and are to be installed in three months.