1,2-Dibromo-3-chloropropane (DBCP) in an amber-colored liquid that has been used as a soil fumigant for nematodes since 1957 in agricultural cropland. Formulations containing DBCP have been primarily sold under the trademarks Fumazone (Dow Chemical, Midland, MI, U.S.A.) and Nemagon (Shell, THe Hague, The Netherlands). Recent reports have associated exposure to DBCP with disruption of spermatogenesis and azoospermia or oligospermia in male workers. Tests on laboratory animals have indicated that DBCP has an adverse effect on spermatogenesis and leads to testicular atrophy. In support of DBCP studies in animals, an analytical method was developed to determine low-level concentrations of DBCP in whole blood. Previous analytical methods for DBCP in blood required extensive sample preparation and steam distillation which limits the number of analysis per time period. This paper describes a simple gas chromatographic-electron-capture detection (GC-ECD) method that is both specific and sensitive to DBCP blood levels at concentrations as low as 2.28 x 10(-1) ng/ml DBCP. In addition, a quantitative analytical method was developed to measure levels of DBCP in drinking water which parallels the method in blood.