Arson is often viewed as the easiest crime to commit but the hardest to prove. Fire investigators must rely on the sensitive chemical analysis of crime scene debris to determine if a flammable liquid or accelerant was used to start the fire. A common method for extracting vapors from fire debris for evidence of an accelerant is the passive headspace analysis. A popular technique of the passive headspace involves the use of activated charcoal strips. Using the Diffusive Flammable Liquid Extraction (DFLEX) device, the volatile products absorbed onto the activated carbon strip are desorbed with a solvent. The most common solvent used is carbon disulfide. This study evaluated solvents, such as diethyl ether, pentane, hexane, and dichloromethane that may provide increased desorption efficiencies over a wider range of accelerants than carbon disulfide without the dangerous properties of carbon disulfide. The research did not provide a clearly ideal solvent for all situations. However, it did confirm the current industry consensus that carbon disulfide offers unsurpassed desorption of gasoline and diesel and very poor desorption of alcohol. Pure dichloromethane was found to give the most consistent desorption across all accelerant types, as well as satisfying the criteria of being less hazardous than carbon disulfide for routine use in casework. References