What's new in ISO 45001:2018/Amd 1:2024

Workplace safety and climate resilience are not separate conversations, and Amendment 1:2024 makes that explicit. On 23 February 2024, ISO published a coordinated update across 31 Annex SL management-system standards, adding climate-change language to the organizational context clauses of every affected standard, including ISO 45001:2018. The amendment is brief and targeted, but it matters, both for audit practice and for the candidates preparing for an ISTO Test of Understanding.

The scale of the human problem that ISO 45001 addresses remains sobering. According to ILO 2019 data, approximately 2.93 million people die from work-related causes every year, around 2.6 million from occupational disease and 330,000 from workplace accidents. That figure gives weight to every clause in the standard, and it is the backdrop against which Amd 1:2024 asks organizations to think about an additional, long-term risk vector: climate.

The February 2024 amendment — what changed in clauses 4.1 and 4.2

The amendment touches exactly two clauses in each of the 31 affected standards. In ISO 45001:2018, both clauses sit within Section 4 (Context of the organization), the same section that grounds the entire OH&S management system in the organization's specific environment.

Clause 4.1 — Understanding the organization and its context

Before the amendment, clause 4.1 required organizations to determine external and internal issues relevant to their purpose and that affect their ability to achieve the intended outcomes of the OH&S management system. Amendment 1:2024 adds a "shall determine" statement: the organization shall determine whether climate change is a relevant issue. The word "whether" carries real meaning. It is a genuine binary question, not an assumption that climate change is always significant. An organization that carefully assesses its context and concludes climate change is not currently a relevant issue can document and defend that conclusion.

Clause 4.2 — Understanding the needs and expectations of workers and other interested parties

Amendment 1:2024 adds a note to clause 4.2 observing that interested parties can have climate-related requirements and expectations. Notes in ISO standards do not add requirements; they signal interpretive intent. Auditors will expect to see climate-related perspectives considered when an organization maps its interested parties, which in ISO 45001 includes not only external stakeholders but, critically, workers themselves.

No transition period — applies immediately

For amendments to Annex SL standards, there is no separate transition period. Unlike a major revision (which typically carries a two- or three-year transition window), an amendment applies at an organization's next scheduled surveillance or recertification audit from the date of publication. The certification cycle is not reset, and no additional audit visit is triggered.

In practical terms: if your organization's next surveillance audit falls after 23 February 2024, your auditor will expect to see that clause 4.1 considered climate change as a potential issue and that the 4.2 interested-party analysis had climate-related expectations on its radar. What satisfies the auditor is a documented, reasoned judgement about relevance, whichever way it lands, rather than a conclusion fixed in advance.

The ISO 45001:2018 core — what the standard is built on

To understand where the amendment fits, it helps to recall the architecture of ISO 45001:2018 itself. Published on 12 March 2018, it replaced BS OHSAS 18001 and brought occupational health and safety management into the Annex SL high-level structure, the common architecture shared by ISO 9001, ISO 14001, ISO/IEC 27001, and all other major management-system standards. That shared structure is exactly why one coordinated amendment can update 31 standards at once.

Four features of ISO 45001:2018 are particularly exam-relevant:

Worker participation and consultation (Clause 5.4). This is one of the most significant differentiators of ISO 45001 compared with OHSAS 18001. The standard requires organizations to establish, implement, and maintain processes for worker participation at all applicable levels and functions. Workers must be consulted on OH&S matters, not merely informed after decisions are made. This includes workers' representatives and covers issues from hazard identification to continual improvement. For Amd 1:2024, the clause 4.2 note on climate-related interested-party expectations directly reinforces this: if workers identify climate-driven risks (extreme heat, flooding, air quality), those expectations must be captured in the context analysis.

Risk and opportunity (Clause 6). ISO 45001 explicitly requires organizations to determine risks and opportunities, a broader lens than the hazard-only focus of OHSAS 18001. Risks and opportunities must both be addressed, with documented actions and evaluation of their effectiveness. This bidirectional framing means climate change can enter not only as a risk (heat stress, extreme weather disrupting operations) but as an opportunity (improved resilience planning, cross-function awareness).

Mandatory hierarchy of controls (Clause 8). ISO 45001 requires organizations to apply the hierarchy of controls (elimination, substitution, engineering controls, administrative controls, personal protective equipment) in that priority order when controlling OH&S hazards. This is more prescriptive than OHSAS 18001, where the hierarchy was guidance rather than a hard requirement. For climate-related hazards (e.g. heat exposure in outdoor work), the hierarchy provides the framework for selecting appropriate controls.

Leadership (Clause 5). Top management bears direct, non-delegable responsibility for the OH&S management system. Clause 5 requires leadership to demonstrate commitment through visible actions (establishing OH&S policy, ensuring integration with business processes, and actively participating in promoting the system). The Amd 1:2024 context requirements feed directly back to leadership: if climate is assessed as relevant in clause 4.1, leadership must ensure appropriate actions are integrated into planning and operations.

Linking climate resilience to workplace safety

The climate-context requirement in Amd 1:2024 is not merely a box-ticking exercise. The connection between climate and workplace safety is concrete and increasingly documented: extreme heat events drive up heat-stroke risk for outdoor and construction workers; flooding disrupts emergency evacuation routes; wildfire smoke creates respiratory hazards. Organizations that have genuinely assessed climate as "relevant" should expect their clause 6 risk register to reflect that assessment.

This is also where the Annex SL integration shows its value. Because ISO 45001 shares its clause structure with ISO 14001 (environmental management) and ISO 50001 (energy management), organizations certified to multiple standards can conduct a single, integrated context review that satisfies the 4.1 and 4.2 climate requirement across all three. That integration benefit is one of the reasons ISO pursued a coordinated amendment across the full Annex SL family rather than standard-by-standard updates.

What this means for candidates and organizations

For candidates preparing for an ISTO Test of Understanding, Amendment 1:2024 is part of the current examinable standard, ISO 45001:2018/Amd 1:2024. Expect questions that test the distinction between what the amendment does (explicit climate consideration in 4.1; climate note in 4.2) and what it does not do (require specific climate-action programmes, trigger re-certification, or change the hierarchy of controls). Understanding that the amendment is a clarification, not a new substantive requirement, is the key conceptual point.

For certified organizations, the practical steps are modest:

1. Review your clause 4.1 context analysis — ensure climate change was explicitly considered as a candidate issue, with a documented conclusion about relevance.
2. Update your clause 4.2 register — check whether any interested parties (including workers) have raised climate-related expectations, and capture those in the analysis.
3. Connect to your risk register — if climate is assessed as relevant, ensure the clause 6 risk and opportunity assessment reflects that, with appropriate controls where needed.
4. Prepare for audit questions — your next surveillance auditor will probe this area; having a documented, reasoned analysis is the clearest way to demonstrate compliance.

The related standard pages for ISO 14001 and ISO 9001 cover how the same amendment applies in environmental and quality-management contexts. The comparison article From OHSAS 18001 to ISO 45001 covers the broader migration story and the structural changes ISO 45001 brought when it replaced OHSAS 18001 in 2018.