Which is the first basic rule or standard of HSE?

this principle is applicable in food safety as well as H&S:

identify the risk, and remove it! if it can not be removed, it needs to be managed.

Have a hazard free enviroment

I think it can be considered as :" Keep healthy, work safely, protect your environment", I do not have a solid info...

don't do anything unless you're sure it is safe to do it ...