RFID stickers could signal contaminated food

If a food item isn’t safe to eat, it’s best to find that out before someone eats it. But manual testing of every jar and bottle isn’t possible, even when a threat, like the recent baby food scare, is known. MITresearchers have found a way to check many items instantly, non-invasively and from a distance — using the RFID tags many products already have.
RFID, or radio frequency identification, uses a tiny antenna embedded in a sticker or label that’s activated and po