The operations of high-tech semiconductor manufacturing and R&D operations presents a myriad of potential industrial hygiene and safety hazards and problems. Chemical hazards in the semiconductor industry are reviewed in an industrial hygiene format. Exposure potentials are summarized for each step in the development and processing of semiconductor devices. The hazards associated with replacement substitutes for III-V compounds are also presented. Risk assessment of the hazards involved in these processes requires that redundant control technology be employed. Controls in semiconductor research and development are reviewed including limiting orifices on compressed gas cylinders, ventilated gas cabinet for storage of compressed gases, dedicated exhaust risers, exhaust flow sensors, multipoint gas monitoring systems, interlocked devices for exhaust and power failure, smoke and fire detection, and fire suppression.