TO DATE, BOMB INVESTIGATIONS HAVE BEEN HAMPERED BECAUSE EXPLOSIVES SELF-DESTRUCT, LEAVING CRIME INVESTIGATORS FEW CLUES AS TO THE ORIGIN OF THE BOMB OR THE MATERIALS USED TO MAKE IT. IN 1976 ATF AND THE 3M COMPANY COOPERATED IN THE DEVELOPMENT OF A TAGGING DEVICE, A PLASTIC CHIP THE SIZE OF A GRAIN OF SAND. THESE CHIPS ARE EASILY RETRIEVED BY MAGNETS AND CAN BE 'READ' WITH A HANDHELD ULTRAVIOLET LIGHT. A PILOT TAGGING PROJECT HAS BEEN UNDERWAY SINCE 1977, AND ATF NOW REQUIRES ALL MANUFACTURERS TO TAG EXPLOSIVE MATERIALS. COMBINED WITH SALE RECORDS, THIS DEVICE CAN PROVIDE VALUABLE INFORMATION IN CRIMES USING EXPLOSIVES. ATF HAS ALSO ISSUED REGULATIONS REQUIRING THE REPORTING OF THEFT OR LOSS OF EXPLOSIVES TO ATF. TRAINING IN THE USE OF THE SPECIAL TECHNIQUES REQUIRED TO RECOVER TAGGANTS IS BEING OFFERED TO LAW ENFORCEMENT PERSONNEL. A RECOVERY KIT CAN BE ASSEMBLED BY A POLICE DEPARTMENT FOR ABOUT $150. THE NEXT PHASE OF THE PROGRAM INVOLVES DEVELOPING A TECHNIQUE FOR TAGGING FOR DETECTION. THIS WILL ENABLE LAW ENFORCEMENT AND SECURITY PERSONNEL TO DETECT HIDDEN EXPLOSIVES. AN APPENDED ARTICLE DESCRIBES THE USE OF TAGGING TO TRACE PAINTS, PLASTICS, ANIMAL AND POULTRY FEEDS, AND OTHER SOLID OR SEMISOLID MATERIALS. TAGGANTS MAY SOMEDAY ENABLE CRIME LABORATORIES TO TRACE EXACTLY THE ORIGIN OF PAINT ON TOOLS, MACHINERY, OR OTHER ITEMS. THE ARTICLE IS ILLUSTRATED. (GLR)