OHSAS 18001 was formally withdrawn in March 2021. If you are still referencing it in tender documents, supply chain questionnaires, or insurance submissions in 2026, the chances are that whoever is reading those documents knows the standard no longer exists — and is drawing their own conclusions about how current your health and safety management actually is.
What changed
ISO 45001:2018 replaced OHSAS 18001 and brought occupational health and safety management into the same high-level structure used by ISO 9001 and ISO 14001. The practical effect is that the core system components — hazard identification, risk assessment, legal compliance, objectives, internal audit, management review — are broadly familiar to anyone who has worked with either of the older standards. The terminology updated and the standard became more explicit about worker participation and consultation, but the fundamental discipline is the same.
If you held OHSAS 18001
Transition to ISO 45001 should have happened before March 2021. If you had a valid certificate that you allowed to lapse without transition, you are not currently certified to any recognised standard. The path back is a fresh ISO 45001 implementation and certification audit, not a transition assessment.
If you are implementing from scratch
ISO 45001 is the only current international standard for occupational health and safety management systems. It is the correct starting point for any UK business seeking external certification, regardless of what a tender document might say. If a customer's questionnaire asks for OHSAS 18001, respond with your ISO 45001 certificate and a brief note explaining the transition — any competent procurement team will accept this.
The legal compliance question
ISO 45001 requires you to identify applicable legal and other requirements related to occupational health and safety — the Health and Safety at Work Act, the Management of Health and Safety at Work Regulations, COSHH, RIDDOR, and any sector-specific legislation relevant to your activities. This is not optional compliance with the standard; it is a core requirement that auditors test in depth. Businesses that treat this as a box-ticking exercise rather than a genuine legal review typically collect nonconformities.
Who should pursue ISO 45001
Construction, manufacturing, logistics, facilities management, and field service businesses are most frequently asked for it by clients and principal contractors. It is increasingly appearing in public sector supply chain requirements and is sometimes required by insurers in higher-risk sectors. If you are bidding for work where the client controls the site, expect to be asked.
Frequently asked questions
What replaced OHSAS 18001?
ISO 45001:2018 replaced OHSAS 18001 as the international standard for Occupational Health and Safety Management Systems. OHSAS 18001 was formally withdrawn in March 2021. Certificates still referencing OHSAS 18001 are no longer to a current standard.
Is an OHSAS 18001 certificate still valid in 2026?
No. OHSAS 18001 was withdrawn in March 2021. Any certificate issued to OHSAS 18001 is no longer to a recognised current standard. If your certificate references OHSAS 18001, you are not currently certified to any valid occupational health and safety management system standard. The path back requires a fresh ISO 45001 implementation and certification audit.
What are the main differences between ISO 45001 and OHSAS 18001?
ISO 45001 adopts the Annex SL high-level structure shared by ISO 9001 and ISO 14001, making it easier to integrate with other management systems. It places greater emphasis on leadership commitment, worker participation and consultation, proactive risk management, and the context of the organisation. It also explicitly addresses opportunities for improvement, not just risk management.
If a tender asks for OHSAS 18001, can I submit an ISO 45001 certificate instead?
Yes. ISO 45001 is the recognised successor to OHSAS 18001. If a customer's questionnaire asks for OHSAS 18001, respond with your ISO 45001 certificate and a brief note explaining that OHSAS 18001 was withdrawn in March 2021 and ISO 45001 is its replacement. Any competent procurement team will accept this.
How long does it take to transition from OHSAS 18001 to ISO 45001?
For organisations with a functioning OHSAS 18001 management system, transition to ISO 45001 typically takes 6 to 10 weeks — significantly less than a fresh implementation. The underlying system is already in place; the work involves gap analysis against the new requirements, updating documentation, addressing the strengthened worker participation requirements, and conducting a transition audit.
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