A bung-plug lock apparatus for preventing a bung-plug (14, 16) from being unscrewed from a drum bung (12, 14) includes an elongated locking plate (38, 38') having a mounting portion (40, 40') for engaging the bung-plug and a locking portion (44, 44') extending radially outwardly from the bung-plug for contacting an inner surface of a raised rim of a drum to prevent the bung-plug from being rotated to unscrew it from the drum. The mounting portion has slots for receiving laterally positioned arms (34, 34') of a U-bracket (30, 30') attached in an external cavity of a standard bung plug. A retaining cable loop (52), having a unique serial number (62), passes through holes (50, 50') in the arms for retaining the locking plate on the bung plug. The locking plate can be turned over and used as a wrench for removing the bung plug. A method of handling hazardous waste in drums includes the steps of applying the bung-plug lock apparatus to a bung-plug of a drum and noting the unique serial number of the cable loop thereof in documentation setting forth the contents of the drum.