The innovative lema 0-litre urinal operates without water and does not require a water shut-off device or electricity to keep the drain closed. The urine itself helps to keep gases sealed in and to prevent their escape. The principle behind this “trap” is known in the chemical industry as the Erlenmeyer flask.
The rate of evaporation of the urine in the "trap" is extremely low. Even if the urinal has not been used in a long time, very little odor is emitted. The small amount of air that escapes passes a citrus aroma-scented block. The 0-litre urinal should be cleaned regularly with water at intervals that depend on the frequency of usage. The water can flow off directly via the existing drain.
The siphon in the 0-litre model can be replaced just as easily as the siphon in the 1 liter urinal.
No matter whether lema is used with a 1-litre or 0-litre siphon, the potential savings compared to the standard two-liter urinals are enormous. At a rate of 300 flushes per day, it is possible to save the amount a family of four would consume in nearly three years when using 5 lema 1-litre urinals. With the lema 0-litre urinal, the saving is almost six years worth of water.