ISO 45001 legal requirements and risks

Answer:
Strictly speaking, clause 6.1.3, determination of legal requirements and other requirements, talks about having a process to determine what laws and other requirements apply to your OHSMS, how they apply, and what you need to do about them. This section does not necessarily link to the previous clauses about risks and opportunities. They are only together in clause 6.1, actions to address risks and opportunities, because the final sub-clause 6.1.4, planning action, applies to everything in the clause (hazards, risks, opportunities and legal requirements). Plans need to be made for all four of these things which have been determined.
That being said, it is possible that legal requirements could result in risks and opportunities. For instance, if you found out that a legal requirement was changing that would make a chemical that was critical to your operations impossible to use this could be a risk or opportunity for you r company. If the easy replacement chemical is more hazardous to use, this is a risk for your organization. Likewise, finding a less hazardous chemical to use would be an opportunity to improve your OH&S performance, and this opportunity may only have come around due to the change in legal requirements.
For a better understanding of all the ISO 45001:2018 requirements, see the whitepaper; Clause-by-clause explanation of ISO 45001:2018, https://info.advisera.com/45001academy/free-download/clause-by-clause-explanation-of-iso-45001