What sets OHSAS 18001 apart from other OH&S management system standards is its widespread use for third-party certification. Over 16,000 organizations have certified their OH&S management systems to OHSAS 18001

OHSAS 18001 was developed and written by the OHSAS Working Group – an independent group of national standards bodies, certification bodies (registrars) and other interested parties

In 2005, the OHSAS Working Group decided to revise OHSAS 18001 to align it with ISO 14001:2004. After a 2-year period of drafting and public review, the revised standard was published in July of 2007. During the revision process, hundreds of comments were received from groups and individuals around the world. These comments were reviewed in two drafting meetings of the OHSAS Working Group — the first in Madrid in October of 2006 and a second in Shanghai in March of 2007

Based on the public comments received, a number of key changes were made to the OHSAS 18001 standard. Of these, five are particularly significant:

1. Improved alignment with ISO 14001:2004

2. A change in the hazards and risks OHSAS 18001 is intended to cover

3. New requirements related to hazard identification, risk assessment and management of change

4. New requirements for external consultation and worker participation

5. Clarification of the role of incident investigation