Abstract
To change the present flush type toilets into the composting toilets is the one of solution methods of prevention of water resource and recycling of nutrition. However it is necessary to mind about secondary infection of a pathogen through this type toilet because the excrement is left in it.
In this research, the microbial risk assessments were applied to the composting toilet for investigating the hygienic safety of it. For the exposure assessment, direct and indirect routes were assumed and required removal ratio of pathogen was discussed. Consequently, viral risks were assumed to be higher than bacterial risks, and it was also assumed that risks through indirect routes were as high as the case through direct routes.
