China stepped up efforts to contain the fallout from the tainted dairy scandal over the weekend, announcing a new survey of dairy products and issuing new quality assurance measures, AFP reported. The survey conducted by the General Administration of Quality Supervision, Inspection and Quarantine (Aqsiq) tested more than 600 batches of liquid milk from 27 Chinese cities. All samples were free of the chemical melamine. Top-selling dairy brands Yili, Mengniu and Bright Dairy, whose goods previously were found contaminated with melamine, all passed inspection this time. The Aqsiq also said it had dispatched more than 5,000 inspectors to carry out 24-hour supervision of dairy factories. Trace amounts of melamine in dairy products have been blamed for the deaths of four Chinese children and for sickening 53,000.