OHSAS 18001, Occupational Health and Safety Assessment Series, was an international standard for occupational health and safety management systems that was subsequently adopted as a British Standard. Compliance with it enabled organizations to demonstrate that they had a system in place for occupational health and safety. BSI cancelled OHSAS 18001 to adopt ISO 45001. ISO 45001 was published in March 2018 by the International Organization for Standardization.[1] Organizations that are certified to OHSAS 18001 were able to migrate to ISO 45001 by March 2021 to retain a recognized certification.[2]