Question regarding Bacillus subtilis recovery when testing for absence of Salmonella sp.

The Question posed on LinkedIn:

Dear experts, During microbial contamination testing for specific organisms – salmonella growing was observed. identification shows that is not Salmonella, but Bacillus subtilis. How i shoud interprated the results, pass specification or not?

There were plenty of replies and I replied to an answer with some additional guidance.  My reply was this:

I would add that if B. subtilis has been found, what is the risk to the end user, (and also product efficacy).    If you are testing for Salmonella sp. then I assume the product is meant for ingestion.  Spores can survive cooking and germinate under warm conditions.  If the product is meant to be stored in a fridge, assume the end user will keep it on a bench.  That could lead to illness, especially in an already ill patient.  I recommend quarantining the batch and conducting a full investigation and risk assessment.  G M Butcher’s site contamination concerns are also valid.