The first transfusion of whole blood was in 1818; however, common use did not begin until the First and Second World Wars. It is on the World Health Organization's List of Essential Medicines, the safest and most effective medicines needed in a health system. In the 1980s the cost of whole blood was about US$50 per unit in the United States. Whole blood is not commonly used outside of the developing world and military. It is used to make a number of blood products including packed red blood cells, platelet concentrate, cryoprecipitate, and fresh frozen plasma.