Iran ranks fifth in onion onion production and also prevents some cancers and can even stop the growth of cancer cells. Onions have anti-cholesterol properties. This property of onion is due to its antioxidant and omega-3 properties. What guarantees the success of onion exporting companies in the target market is offering better products, proper packaging and paying attention to the weight of onions in each carton. Onions for export Onion exporting companies must be sent in standard packages in cartons of specified weight for export. Onions that fall into these categories should be the same size and be classified in one grade. Export onion grade is expressed in 3 ways; In grade 1, onions should be about 2 inches or larger in diameter; In grade 2, the diameter of the onion should be from one to 2 inches, and in grade 3, the diameter of the onion should be less than 1 inch.