That's sad, and also a food safety risk. I also think it's vastly different to ask the last 48 hour of history of vomiting and diarrhoea vs intent to have children or another protected characteristic like potential disability. How did you cope in Covid?
Is there no way of working with HR or unions or something to find out what you can ask, what you can't and how that information is retained? There are strong data protection laws around personal information in the UK and it can only be collected for a reason but this, to my mind is a reason.
Anyway, it appears the person asking is in the UK from the reference to SALSA so the FSA example is certainly a great place to start and while it's completely box ticking, I have put signage by clocking in machines to say something along the lines of:
"By clocking in, I confirm I am not suffering from vomiting, diarrhoea within the last 48 hours" etc.
Nobody would have read it but it ticked a box for a retailer standard.
Be thankful anyway. This is light touch! 20 years ago a full medical was sometimes required for the food industry AND I had to have stool testing for two chilled employers. 