OHSAS is the acronym for Occupational Health and Safety Assessment Series. This is from a series of standards that were issued by the British Standards Institute (BSI) in 1999, which included 2 standards; OHSAS 18001:1999 & OHSAS 18002:1999. On the other hand, OHSMS is the acronym for Occupational Health & Safety Management System. The OHSMS is all of the rules, policies, processes and procedures that an organization puts in place to continually improve OH&S performance, fulfil legal and other OH&S requirements and achieve OH&S objectives for the company. While OHSAS 18001:2007 previously provided the requirements for an OHSMS, now that ISO 45001:2018 has been released as the internationally recognized requirements for an OHSMS, it will replace OHSAS 18001:2007.