All those working with food products, need to follow a course about food safety, specific for their line of work, and pass an exam, thus obtaining their ´food handler certificate´ or ´carnet de manipulador de alimentos´. Courses often organised by town hall, by the Employment Agency SEPE or you can do it online. Just Google the Spanish description above.
Those issued before 2010 were only valid for 4 years and had to be renewed after that, but in 2010 the food handling courses were re-structured by law and certificates issued after that, do not expire. Employers are encouraged to send their employees to a refresher course every 4 to 5 years and are required to show proof of sufficient formation of their employees with respect to food safety when they receive an inspection visit from the Food and Safety Department.