There are tags designed for tracking medical devices that are small and can withstand high temperatures. The Pico X II tag, from Xerafy, measures 0.7 inch by 0.43 inch by 0.19 inch and can withstand temperatures ranging from -40 degrees to +150 degrees Celsius (-40 degrees to +302 degrees Fahrenheit). And the company’s Dash-On XS tag, which measures 0.48 inch by 0.12 inch by 0.09 inch, can withstand similar temperatures. These tags are likely too large for use with eating utensils, however. There are even smaller tags that can be inserted into a cavity drilled into metal, which can then be filled with epoxy, but the read range on such tags is only a few inches, which might not help you very much.
—Mark Roberti, Founder and Editor, RFID Journal