The usefulness of behavioral methods for the reduction of worker exposures to toxic chemicals was investigated. A meeting was held with 18 hourly employees who worked in a fiberglass reinforced plastic parts manufacturing department to discover what the workers knew about styrene (100425) exposure, to describe a planned research study, and to gain the cooperation of these workers. Special attention was given to the individuals employed as gelcoater, chopper, rollout person and repairer in order to determine whether specific behaviors might be modified which would in turn either increase or reduce exposure to styrene. During this time measurements were also taken of the exposure to styrene, the productivity of the workers, and the amount of time spent working. The following changes in work practices were initiated. The four workers each began to place the molds in such a position as to take advantage of the exhaust ventilation and use the airflow in the work areas to their advantage. The chopper, rollout person, and gelcoater began to use gloves and wear long sleeves. Both sprayers started to operate with the doors of the spray booth closed and the guns directed so that most of the spray fell on the molds. The floor fans were activated by the rollout person and repairer. The chopper no longer sprayed toward the other workers. Before retraining, breathing zone air samples indicated 150 parts per million (ppm) concentrations of styrene. Following retraining, the mean was 96ppm. Also following training, a temporary decrease of 5 to 15 percent occurred in the productivity of the chopper and gelcoater. Baseline productivity rates were regained within 4 days.