providing the secretariat. Drawing on the best of existing standards and schemes, the Occupational Health and Safety Assessment Series Project Group published the world's first international occupational health and safety management systems standard, OHSAS 18000 series in March 1999. The series consisted of two specifications: OHSAS 18001 provided requirements for an OHS management system and OHSAS 18002 gave implementation guidelines.

OHSAS 18000 series was updated in July 2007, based on conventions and guidelines of the ILO,