Can a director be prosecuted for a breach of this, & other legislation if the director has retired from the company?

There is no statute of limitation in the UK and if you are personally found responsible (as said not corporate manslaughter) for a criminal office they can pursue you to your grave.

None I suspect. I was just saying what the law is who gets prosecuted is a matter of policy down to the HSE and CPS.
In the case mentioned it seems that the new MD was being treated as the 'controlling mind' of the company . it's form of vicarious liability I suppose

1 retired director rang me for help >6 months after he left the business when he had 2 [reference removed] sitting in his lounge!

There is no individual liability under the Corporate Manslaughter and Corporate Homicide Act 2007. Which means individuals cannot be prosecuted for corporate manslaughter.

Individuals remain liable under the common law offence gross negligence manslaughter, which hinges of foreseeability and proximity.

S37 of the 1974 Act does not create a specific offence, it extends a form of secondary liability,

Section 37 (1) states that where an offence under any of the relevant Statutory Provisions committed by a body corporate is proved to have been committed with the consent, connivance of, or to have been attributed to any neglect on the part of any Director, Manager, Secretary, or other similar Officer, of the body corporate, or a person who was purporting to act in any such capacity, they as well as the body corporate shall be guilty of that offence and shall be liable to be proceeded against and punished accordingly.

I have just completed a masters of law degree in health, safety and environmental law, and my dissertation topic was on corporate manslaughter, if anyone would like a copy so they can understand area of law better, then send me a PM.

Thanks

Dave