Separation and detoxification reactions often can be run advantageously using supercritical fluids (SCFs) as processing media. The use of a supercritical solvent frequently permits extraction of very dilute toxic species, either directly or in a two-step process. SCF solvents not only increase reactivity but offer the potential for simultaneous separation and detoxification. SCF technology is a powerful tool that has a bright future in environmental engineering applications.