What the standard is, whether you need it, and how it relates to the HSWA
ISO 45001 is the international standard for an occupational health and safety management system, adopted in New Zealand as AS/NZS ISO 45001:2018. It is voluntary — not a legal requirement — and is built on the Plan-Do-Check-Act cycle. It does not replace your HSWA duties, but a good system covers much of the same ground.
ISO 45001 is the international standard that sets out the requirements for an occupational health and safety management system — a structured way to manage health and safety and continually improve it.
Published in 2018, it replaced the older British standard OHSAS 18001, and in this part of the world it superseded the previous AS/NZS 4801 standard. It is adopted locally as AS/NZS ISO 45001:2018. Rather than prescribing exactly what controls to use, it describes the framework an organisation should have in place: leadership, planning, support, operation, performance evaluation and improvement.
No. ISO 45001 is voluntary. Your legal obligations come from the Health and Safety at Work Act 2015, not from the standard.
You can run a fully compliant health and safety system, and meet all your HSWA duties, without ever adopting or certifying to ISO 45001. What the standard offers is a recognised, internationally consistent framework — and a good ISO 45001-style system naturally covers much of what the HSWA expects (managing risk, engaging workers, recording and reviewing). Some clients, head contractors or tenders ask for ISO 45001 certification as a condition of doing business, which is often the practical reason organisations pursue it.
ISO 45001 follows the Plan-Do-Check-Act (PDCA) cycle, the same continual-improvement loop used across ISO management standards.
| Stage | What it covers |
|---|---|
| Plan | Understand your context, lead from the top, identify hazards and risks, set objectives. |
| Do | Put the controls, resources, training and operational processes in place. |
| Check | Monitor, measure, audit and review how the system is performing. |
| Act | Correct what isn't working and continually improve. |
Because it shares the Annex SL “high-level structure” with ISO 9001 (quality) and ISO 14001 (environment), ISO 45001 is designed to integrate cleanly into a single management system rather than sit on its own.
Certification is an independent audit confirming your system meets the standard — it is optional, and ISO 45001 can be implemented without it.
If you do want certification, it is carried out by an accredited certification body (in New Zealand and Australia, accreditation is overseen by JAS-ANZ). Many organisations adopt the principles of ISO 45001 to strengthen their system without seeking formal certification, and only certify when a client or tender specifically requires it. Either way, the value is in actually running the management system, not in the certificate on the wall.
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No. ISO 45001 is a voluntary standard. Your legal health and safety obligations come from the Health and Safety at Work Act 2015, and you can meet them in full without adopting or certifying to ISO 45001.
The HSWA is New Zealand law and sets out duties you must meet. ISO 45001 is a voluntary international standard describing a framework for a health and safety management system. A good ISO 45001-style system supports HSWA compliance, but the standard does not replace your legal duties.
Yes. ISO 45001:2018 replaced the British standard OHSAS 18001, and it superseded the older AS/NZS 4801 used in Australia and New Zealand. Organisations certified to those older standards were expected to transition to ISO 45001.
Not legally. Certification is optional and carried out by an accredited certification body. Many organisations adopt the principles of ISO 45001 without certifying, and only seek formal certification when a client, head contractor or tender requires it.
No. ISO 45001 is an international management-system standard, while SiteWise, PreQual and Totika are New Zealand contractor prequalification schemes that assess a business's health and safety capability. They serve different purposes, though a strong management system helps with both.
