I'm actually looking for an IOS standard for physical security rather than ICT security. If you could advise me if an IOS standard exists for physical security I'd be very keen to look at how this might be implemented.
I'm assuming you are referring to an ISO standard for physical security. Considering that, please note that physical security is a broad topic (e.g., from the protection of facilities to protection of credit card readers), so without further detail is not possible to give you a more precise answer.
What I can tell you is that most of ISO standards related to physical security are related to Information Technology (e.g., ISO/IEC TS 30104:2015 Information Technology — Security Techniques — Physical Security Attacks, Mitigation Techniques, and Security Requirement, ISO/IEC TS 22237-6:2018 Information technology — Data center facilities and infrastructures — Part 6: Security systems, and ISO/IEC NP 24383 Information technology — Physical network security for the accommodation of customer premises cabling infrastructure and information technology equipment)
In this ISO site, you can make a search more detailed according to your demands: <a href="https://www.iso.org/search.html?q=physical%20security&hPP=10&idx=all_en&p=0&hFR%5Bcategory%5D%5B0%5D=standard