Occupational hygiene (United States: industrial hygiene (IH)) is the anticipation, recognition, evaluation, control, and confirmation of protection from hazards at work that may result in injury, illness, or affect the well being of workers. These hazards or stressors are typically divided into the categories biological, chemical, physical, ergonomic and psychosocial. The risk of a health effect from a given stressor is a function of the hazard multiplied by the exposure to the individual or group. For chemicals, the hazard can be understood by the dose response profile most often based on toxicological studies or models. Occupational hygienists work closely with toxicologists (see Toxicology) for understanding chemical hazards, physicists (see Physics) for physical hazards, and physicians and microbiologists for biological hazards (see Microbiology Tropical medicine Infection) Environmental and occupational hygienists are considered experts in exposure science and exposure risk management. Depending on an individual's type of job, a hygienist will apply their exposure science expertise for the protection of workers, consumers and/or communities.
The British Occupational Hygiene Society (BOHS) defines that "occupational hygiene is about the prevention of ill-health from work, through recognizing, evaluating and controlling the risks". The International Occupational Hygiene Association (IOHA) refers to occupational hygiene as the discipline of anticipating, recognizing, evaluating and controlling health hazards in the working environment with the objective of protecting worker health and well-being and safeguarding the community at large. The term "occupational hygiene" (used in the UK and Commonwealth countries as well as much of Europe) is synonymous with industrial hygiene (used in the US, Latin America, and other countries that received initial technical support or training from US sources). The term "industrial hygiene" traditionally stems from industries with construction, mining or manufacturing, and "occupational hygiene" refers to all types of industry such as those listed for "industrial hygiene" as well as financial and support services industries and refers to "work", "workplace" and "place of work" in general. Environmental hygiene addresses similar issues to occupational hygiene but is likely to be about broad industry or broad issues affecting the local community, broader society, region or country.