Can the amount of toxic waste released into the environment by manufacturing facilities be reduced by formally involving employees in pollution prevention? Pursuant to the Pollution Prevention Act of 1990, the U.S. Environmental Protection Agency began requiring that manufacturers report human resource management strategies related to "source reduction" (reduction of waste at the source), as part of the Toxics Release Inventory (TRI). These strategies often involve employee participation in some form. Here we report the preliminary findings of an ongoing study of the effect of employee participation on source reduction, based on the 1991-1992 TRI database. We find, for example, that manufacturers using a certain combination of three formal employee participation practices had triple the reduction in emissions of manufacturers using none of these practices. We also discuss competing predictors of source reduction, and future research directions.