The effect of perchlorate in the body at doses above 0.007 milligrams per kilogram per day (equivalent to 245 ppb in drinking water using EPA default assumptions) will be the same, regardless of whether its source is from drinking water or food. Perchlorate is not absorbed through the skin. To calculate the total dose from all sources, however, it is not correct to add the concentrations found in water, milk and various other foods. When calculating a total dose, the amounts of water, milk and other foods that a person ingests must be considered.