THE LABORATORIES WERE SENT A WHITE POWDER SAMPLE, TOGETHER WITH THE INDICATION THAT THE SUBSTANCE WAS A 'STREET BUY' AND THAT THE AGENT NEEDED ALL THE QUALITATIVE AND QUANTITATIVE INFORMATION THE LABORATORY COULD PROVIDE. THE LABORATORIES WERE ALSO ASKED TO INDICATE THE METHODS USED TO ANALYZE THE SUBSTANCE. OF THE 179 RESPONDING LABORATORIES, 125 REPORTED CORRECTLY THAT THE POWDER CONTAINED HEROIN AND COCAINE; 52 IDENTIFIES ONLY HEROIN (SOME LOCAL LAWS MAKE IT UNNECESSARY FOR LABORATORIES TO PERFORM ADDITIONAL ANALYSIS AFTER ONE CONTROLLED SUBSTANCE HAS BEEN IDENTIFIED); 1 REPORTED ONLY COCAINE; AND 1 COULD NOT IDENTIFY THE POWDER. METHODS SUCH AS GAS CHROMATOGRAPHY/MASS SPECTROMETRY, EXTRACTION, AND GAS CHROMATOGRAPHY WERE USED MORE FREQUENTLY BY LABORATORIES THAT IDENTIFIED BOTH SUBSTANCES, WHEREAS MICROCRYSTALLINE TESTS WERE USED MORE FREQUENTLY BY LABORATORIES THAT IDENTIFIED ONLY HEROIN. DETAILS OF RESULTS, INCLUDING BREAKDOWNS OF METHODS AND FINDINGS FOR INDIVIDUAL LABORATORIES, ARE REPORTED IN 11 TABLES. INFORMATION ON SURVEY METHODS AND A COPY OF THE QUESTIONNAIRE ARE INCLUDED. OTHER PROFICIENCY SURVEYS INVOLVING DRUG ANALYSIS ARE REPORTED IN NCJ-47522 (BARBITURATES) AND 47536 (AMPHETAMINES). SURVEYS FOR OTHER SUBSTANCES ARE REPORTED IN NCJ 47523 - 47526, 47528 - 47535, AND 47537 - 47542. (LKM)