Buyer´s requirements oblige private and public agents to take quality control measures, in order to be competitive in the export markets. Labor performance and final product quality require introduction of control methods, particularly among temporary workers who require training to become highly productive in short time. Evidence compiled in this research show the existence of significant differences in knowledge of variables related to hygienic food manipulation, before and after training; and, differences between firms that explicitly apply regulations and others that do not. Mc Nemar´s statistical methods and attribute graphics are utilized for determining failures in standard control process. Both tests are applied to temporary fruit export packing workers. The conclusions have practical consequences leading to adoption of control practices related to quality.