Techniques for on site screening of benzene (71432) in workplace air were described and compared. The accuracies of three portable gas chromatographs, sorbent tube samples, and three types of detector tubes were examined by analysis of field samples collected during routine inspections of marine vessels. An integratable response with the retention time of benzene was identified using each of the three chromatographs tested; however, some interference was present in certain samples. The portable chromatographs were successful in detecting benzene in concentrations below the OSHA permissible exposure limit of 1 part per million and had a total analysis time of less than 10 minutes. The detector tubes were less precise and indicated higher benzene concentrations than the chromatographs; however, the results they provided regarding whether a space was within the 1 part per million safe for entry benzene concentration were in agreement with those obtained using the other techniques. Similar to the detector tubes, the charcoal tubes, which had to be sent for laboratory analysis, in some instances provided conservative estimates of safety.