Ecological sanitation is aimed at closing the nutrient and water cycles. Nutrients from human excreta should be returned to the soil to fertilize crops and urine is diverted from faeces in eco-toilets, and reused as fertilizer. To avoid the risk of being exposed to pathogens it is important to reduce contact with the excreta, and to decrease the number of pathogens in the material. Soil is a natural sanitization system for faeces, but its effectiveness is difficult to predict. Contamination of urine with faeces considerably increases the need for urine sanitization. Current WHO guidelines stipulate that if a set of barriers are maintained, treatment of excreta is not considered necessary. This paper tracks the WHO's practical recommendations on reuse of urine and faeces.