An Occupational Hygienist (OH) – also referred to as an Industrial Hygienist (IH) – is a professional who identifies and prevents unhealthy exposures that may cause workplace injuries or illnesses. The OH/IH applies scientific knowledge to anticipate hazardous conditions that could cause an adverse health effect on a worker or the environment. The OH/IH must also be able to recognize existing hazards and predict the likelihood of their effects. Combining professional judgment and measurements, the OH/IH evaluates hazards and determines methods for preventing or controlling them.

Example: Woodworking has a number of hazards: amputations and hand injuries from blades, eye injuries from flying objects, respiratory disease from inhaling wood dust and solvent, paint or glue vapors. An industrial hygienist would be concerned with anticipating these hazards and designing woodworking equipment and workers’ jobs to minimize the effects of these hazards. The industrial hygienist might take samples of wood dust from a worker’s breathing zone to measure exposures, compare these measurements with regulatory guidelines, and make recommendations for installing better dust collection systems.

The professional certification for this field is the CIH, Certified Industrial Hygienist. Eligibility is based on baccalaureate degree and work experience. A masters degree from an ABET-accredited program counts toward work experience. Certification is obtained by passing two written examinations: Core and Comprehensive (each one day in length). Certification must be maintained, either by re-taking the exam or by approved activities. The American Board of Industrial Hygiene is responsible for professional certification.