The validity period and review time limit of Wuhan Hygiene Permit are as follows: the validity period of food hygiene permit is 3 years (the validity period of small certificate and canteen permit is one year), and it is reviewed once a year; The validity period of the hygiene license for public places is 3 years, and it is reviewed once every two years; The drinking water hygiene license is valid for 4 years and reviewed once a year; The hygiene license for dry cleaners is valid for 2 years and reviewed once a year; The health permit of medical institution is valid for 5 years and reviewed once a year; The work permit of X-ray device is valid for 3 years, and is reviewed once every 75 years.