Compulsory teaching of general necessary knowledge in the field of food safety. Public welfare food safety training refers to compulsory teaching of general necessary knowledge in the field of food safety. Food safety means that food is non-toxic and harmless, meets the nutritional requirements, and will not cause any acute, subacute or chronic harm to human health. Public welfare training belongs to the category of public welfare education, which refers to free education assistance services for groups of different ages and levels, including but not limited to students, community masses and laid-off workers.