This study assessed personal exposure to 1,3-butadiene (BD) and styrene in three plants manufacturing styrene-butadiene (SB) copolymers. Air samples were collected from the breathing zone of 28 workers over 4 months in three SB plants using diffusive samplers. The total number of samples was 885 with the number of samples per participant varying from 19 to 39. Samples were collected by use of 3M 3500 passive monitors and analyzed with a gas chromatograph (GC). Sampling proved to be simple and inexpensive and laboratory analysis of BD could detect 0.01 and 0.007 part per millions (ppm) of styrene in the 8h samples. In the case of BD, 624 samples were below the limit of quantification (LOQ), 240 samples were between the LOQ and 1 ppm, and 21 samples exceeded the threshold limit value (TLV). In the case of styrene 336 samples were below the LOQ, 548 samples were between the LOQ and 20 ppm. The TLV was exceeded once. The data gives a comprehensive picture of personal exposure of workers in modern SB latex manufacturing plants. The study illustrates also how the new TLV of BD is being implemented.