Definisi tentang K3 adalah yang dirumuskan oleh ILO/WHO Joint safety and Health Committee, yaitu :
Occupational Health and Safety is the promotion and maintenance of the highest degree of physical, mental and social well-being of all occupation; the prevention among workers of departures from health caused by their working conditions; the protection of workers in their employment from risk resulting from factors adverse to health; the placing and maintenance of the worker in an occupational environment adapted to his physiological and psychological equipment and to summarize the adaptation of work to man and each man to his job.
