What is the difference between OHSAS 18001 and 18002?

OHSAS1 is the Occupational Health & Safety Management System specifications. It includes the planning of hazard identification, risk assessment, training & awareness programs, emergency response plans, communication, performance measuring & monitoring etc.

OHSAS2 is the guidelines for the implementation of OHSAS1.

OHSAS  1 is the standard of management system items but OHSAS2 is the handbook which explains how to implement and conduct the standard.