Is mbed os safety approved, IEC 61508, TUV , SIL 3 for example.
Mbed OS does not have those approvements. However it is designed to be secure system in device hardware, software, communication and in the lifecycle of the device itself:
Hardware Enforced Security At the lowest level of Mbed OS, we use a supervisory kernel called uVisor to create isolated security domains which restrict access to memory and peripherals.
Communications Security We take SSL and TLS, the standard protocols for securing communications on the internet, and allow you to include them in your Mbed project with a simple API.