Participants received different amounts of information in either a cTRAIN computer-based instruction (CBI) program or in a booklet format, presented before or concurrently with interactive questions about the information. An interactive CBI presentation that required an overt response during training produced equivalent acquisition and retention to showing questions with the correct answers underlined in a book. "Open book tests" proved to be an effective teaching strategy, compared to requiring overt responses on tests in a CBI format. Retention did not prove durable over 1 week or 1 month in any format. These results confirm and extend research in college populations to adults in the workforce and raise serious concerns about the durability of workplace safety and health training beyond an immediate post-training test.