Work is essential for life, development and personal fulfillment. Unfortunately, indispensable activities such as food production, extraction of raw materials, manufacturing of goods, energy production and services involve processes, operations, and materials which can, to a greater or lesser extent, create hazards to the health of workers and those in nearby communities, as well as to the general environment.

However, the generation and release of harmful agents in the work environment can be prevented, through adequate hazard control interventions, which not only protect workers’ health but also limit the damage to the environment often associated with industrialization. If a harmful chemical is eliminated from a work process, it will neither affect the workers nor go beyond, to pollute the environment.

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 profession of occupational hygiene uses strict and rigorous scientific methodology and often requires professional judgment based on experience and education in determining the potential for hazardous exposure risks in the workplace and environmental studies. These aspects of occupational hygiene can often be referred to as the "art" of occupational hygiene and are used in a similar sense to the "art" of medicine. In fact "occupational hygiene" is both an aspect of preventive medicine and in particular occupational medicine, in that its goal is to prevent industrial disease, using the science of risk management, exposure assessment and industrial safety. Ultimately professionals seek to implement "safe" systems, procedures or methods to be applied in the workplace or to the environment.