Despite health concerns regarding exposure to 1,3-butadiene, there is a dearth of Validated methods for its determination in nonoccupational environments. A sampling and analytical methodology is Validated for determining 1,3-butadiene in such environments. Samples were collected via sorbent tubes containing 1000 mg of Carbopack B and 150 mg of Carbosieve Sill and analyzed by TO (thermal desorption)-GC/MS. This sorbent combination was compared to that of 600 mg of Carboxen 569. When sampling for 2 h at 30 mt min(-1), 20 degrees C and relative humidity 60%, Carbopack B/Carbosieve Sill gave 1,3-butadiene recoveries >95%, compared to ca. 60% for Carboxen 569. The combined sampling and analytical precision of Carbopack B/Carbosieve ill was 13% at 0.17 mu g m(-3), with a detection limit <0.16 mu g m(-3). Optimum sampling conditions were as follows: duration 2 h, flow rate 30 mt min(-1), maximum temperature 35 degrees C. The impact on sampling efficiency of ozone concentrations and relative humidity was negligible. Simultaneous sampling with both Carboxen 569 alone and Carbopack B/Carbosieve SIII in a range of nonoccupational environments and sampling conditions revealed 1,3-butadiene concentrations to be 24-58% when the latter sorbent was used, suggesting that measurements made using carbon molecular sieve sorbents such as Carboxen 569 are underestimates.