Enviro PTC does not contain formaldehyde So it is more user friendly than formaldehyde containing disinfectants
Direction for Use:
Chemical Toilets:Pour 80ml of Port A Pottie directly into tank.
Recirculating Toilets:Add 150ml of Port A Pottie directly into initial charge
Large Holding Tanks:Add 90ml of Port A Pottie directly per 50 litres capacity