The World Health Organization and Food and Agriculture Organization of the United Nations are at the forefront of managing public health hazards. Foodborne diseases are caused by pathogenic bacteria or viruses transmitted through contaminated food at any stage from production to consumption, putting infants, children, the elderly and immunocompromised people particularly at risk of gastrointestinal or more serious neurological, immunological or cancerous symptoms. In recent decades, most diseases have been caused by pathogenic bacteria or viruses originating from food animals and animal products, though some are caused by environmental contaminations from chemicals like fertilizers and pesticides. The five keys to safer food explain basic principles to prevent foodborne illness.