Occupational hygiene involves recognizing, evaluating, and controlling health hazards in the workplace to prevent ill health. It deals with chemical, physical, biological, and ergonomic hazards through risk assessment, exposure monitoring, and advising on control measures such as engineering solutions, work practices, personal protective equipment, supervision, maintenance, procedures, auditing, testing, health surveillance, information, training, and housekeeping. Common hazards addressed include mineral oils, VOCs, benzene, hydrogen sulfide, asbestos, noise, vibration, heat/cold stress, Legionella, zoonoses, anthrax, and ergonomic issues related to manual handling and repetitive work.