The main cause of allergic manifestations among workers handling green coffee beans (GCB) is sensitization to castor beans (CB), which are considered a common contaminant of the sacks used to transport coffee beans. The RAST inhibition test was used to evaluate the presence of GCB and CB allergens on the surface of the sacks coming from the major world producers of coffee and to ascertain the presence of the CB allergen in coffee beans. A significant concentration of the two allergens, i.e., GCB and CB, on the sacks was demonstrated, with the highest values found on sacks from Brazil, while the hypothesis of a significant CB contamination in coffee beans was not confirmed. We believe the presence of the CB allergen on the surface of the sacks is due to contamination occurring during stocking and transport and could easily be prevented. Appropriate measures taken during transport could effectively prevent this "undue" risk in dockers and probably also in coffee industry workers.