ISO 45001/OHSAS 18001 - Occupational Health & Safety certification in Bhopal. Up until March 2018, OHSAS 18001 has been the internationally recognized voluntary standard for OH& S. With the publication of ISO 45001 on March 12 2018, the official status of OHSAS 18001:2007 is “withdrawn”. ISO 45001 is based on OHSAS 18001 and other recognized OH& S standards and conventions. It applies the ISO High Level Structure (HLS), which defines the structure for all ISO standards. The new standard contains some significant changes from OHSAS 18001.