That is a big ask Eddy.

The answer will take some time to compile.

Have a look at the IOD/HSE leadership model INDG417 and some of the other resources available via this very Site.
Plenty of food for thought there.

Eddy: some good advice from teh_boy. It's not really 'your safety policy' is it? Neither is it for the safety adviser to tell others what their job is, which is how such policies come across.

Everyone has (or should have) some kind of job description.
H&S accountabilities are so often not included - I mean proper ones, such as 'carry out a monthly safety tour', not the bland all-inclusive 'comply with H&S requirements' which is fairly meaningless.

You need the HR and operational management to take this on, otherwise it will, frankly, be ignored, however comprehensive you draft responsibilities. The policy should only be broad brush, in levels of responsibility, but then made specific through the organisational JDs.

If it's not in someone's job, they won't / can't be made accountable. If they aren't accountable, it's not important (to them or their manager). If it's not important it won't get done.

I think we all fall down a bit on the way this has tended to be approached: the safety policy should not be a separate supplement to peoples' job roles. Everything they need to know about their job responsibilities should be evident in their JD.

There is quite a bit to this project, to tie up the broad brush 'policy' layers with practical real accountabilities, which can be and should be part of a performance management system. I have rarely seen it done, only in my dreams . .

Maybe if you do it successfully you can share in some way.