Eight techniques for conducting a hazard evaluation were reviewed, highlighting to industrial hygienists the uses, advantages, and disadvantages of each method. These techniques have been used by industry to help protect property and avoid catastrophic incidents, and they can also be used to protect workers in the facility from chronic exposures. The latter was accomplished by focusing the evaluation on occupational control systems and fully identifying the consequences of even the smallest releases. Worker participation was important to the success of any such program. Each technique was useful in its own way and a check list was appropriate for processes with a substantial history. The decision of which method to use was influenced by resources available, size and complexity of the process, and the relative level of hazard inherent in the process. The eight different processes examined included checklists, what if analyses, safety audits and reviews, preliminary hazard analyses, failure modes and effect analyses, fault tree analyses, event tree analyses, and hazard and operability studies. A typical industrial hygiene evaluation of a facility was observed to normally include air sampling. If the air sampling did detect a specific hazardous substance, the source was likely routine or a continuous emission in nature. However, air sampling was not able to identify or predict the location of the nonroutine emission. The authors state that by using these various techniques with typical evaluations, industrial hygienists can proactively help reduce the hazards in the workplace.