Hitachi has developed a radio frequency identification technology (RFID) chip small enough to be embedded (nearly invisibly) into food packages or the inedible parts of fresh fruits and vegetables. Measuring only 0.4 millimeters square, the chip has a tiny antenna that allows an external device to read encoded information stored in the chip for the purpose of tracing the product. Giant retailing chains have hitherto used this technology for monitoring inventory in and out of warehouses but consumers have been concerned about the use of this technology beyond the retail store level. (Don't eat the packaging or the "inedible parts" of fresh fruits and vegetables.)