I've previously had this information but can no longer find it.
I'm aware that the law on motorcycle helmets really came into being with the 1988 road traffic act.
In the bits that I'm able to search on the internet, it goes on about the standards etc, but I can't find the part about these standards being applied retrospective or not.
An inspector that I know, did actually find me the relevant information a couple of years ago, but I can no longer find where I've put it. (Somewhere too safe obviously!)
Basically it said that the BS helmet standards that came into effect with the road traffic act 1988 were not applied retrospective to helmets already in use, only to new helmets sold afterwards.
So a helmet that was originally made as a motorcycle helmet prior to the 1988 act, would still be legal to use.
I would be obliged if someone could point me in the right direction for this particular part of the legislation, thanks.