ISO 14001 and ISO 45001 share the Annex SL structure — context, leadership, planning, support, operation, performance evaluation, and improvement clauses are structurally identical. Most enterprises run them as one integrated management system (IMS): shared context and interested-parties analysis, a single leadership and policy layer, a combined risk / aspects register, one CAPA and incident workflow, a joint internal audit programme, and a single management review that covers both standards.
The payoff is real: combined 14001 + 45001 (often plus 9001) certification audits reduce audit days and total certification cost, and — critically — remove the duplicate spreadsheets and parallel workflows that make surveillance audits painful. If you're already targeting ISO 45001, adding 14001 to the same platform is materially easier than standing up a second system. See the ISO 45001 certification guide.