If a mains spike damages your mains smoke alarms that’s now a safety issue.
... as would there be a 'safety issue' ifm say, a plumbing failure damages the smoke alarms. What 'requirements' would you suggest BS7671 should introduce to address that possibility?
I have to admire your ingenuity - since I did say that barrels had to be scrapped pretty deeply to turn SPDs into a 'safety issue'
You could add 'life-supporting' equipment etc. to your list, as well (although one would hope that would be internally protected against everything it could be protected against).
As I often say/imply, I think that for BS7671 to insist on emergency lighting in all domestic dwellings would require a lot less 'barrel scraping' than things like this - since, once in a blue moon, people may come to harm as a result of 'being plunged into darkness'.
Also your smoke alarms costed more than the SPD that could have saved them.
If tens, or hundreds, of thousands (or, frankly, just a few dozen) have to buy SPDs for each smoke alarm that has to be replaced because it was damaged because of the absence of an SPD, then that arithmetic would turn dramatically on its head.
I presume that even your beloved SPDs are not 100% effective in preventing equipment being (very very occasionally) damaged by 'supply spikes'. Do you therefore think that BS7671 should perhaps insist that all electronic and other equipment which could conceivably be damaged by such spikes must be insured against such happenings?
Kind Regards, John