One of the most important economic developments in recent years is the growth in the number of temporary and contract employees. Little is known, however, about the implications these contingent employees have for human resource practices. This paper presents the results of a study of one group of contingent workers, contract workers in the petrochemical industry. The primary concern of this study is the consequences contract workers have for safety, a hotly debated and politically charged issue in an industry where safety mishaps can have catastrophic consequences. We find that contract employees offer petrochemical firms an important degree of flexibility in meeting rapid fluctuations in their demand for labor. Contract employment relationships also create stresses with potentially severe adverse effects on workplace safety. Overcoming these threats to safety while maintaining flexibility will require a high level of coordination among human resource professionals, line managers, corporate executives, unions, and government agencies.