Study on the risk evaluation model of catering O2O food quality and safety Dong-Ping Tang, Saddam Fuad Hussein Al Qadami, Xue-Min Wang and Cui-Ying Cai E3S Web Conf., 78 (2019) 02013 Published online: 15 January 2019 DOI: 10.1051/e3sconf/20197802013