Forensic Laboratories performed qualitative analyses on the vapors above (head-space) seized cocaine samples during the period of 1986 - 1991. Thirty-two solvents were targets of the chemical head-space analyses. The results of the chemical analyses were statistically analyzed. The statistical analysis revealed trends in chemicals solvents being used or substituted for previously used solvents. This is critical to targeting the right chemicals for diversion control. In the 1991 head-space analyses, five chemical solvents could have been used as screening targets for cocaine contraband. The analysis showed strong trends in chemicals found. Routine statistical analysis of the head-space data will be needed to update the list of target screening chemicals.