Yeah, we do that here, but not with sesame, we don't have sesame in the building. We have wheat, milk, egg, and soy in the building, and every formulation contains all four allergens, some just enough to put it on the ingredient statement, and it's not actually functional in the formula. We've been that way like 25 years, but now inspectors mention it and don't really like it, but I guess we were stacking before it was a big thing, so they don't say much, and what can they say really? Personally, I don't see the harm in doing it even with sesame. It makes life easier, and food safer. It's on the label, it's good, no? What's the issue? I've heard FDA folks say you're following the letter of the law but not the spirit of the law. Then rewrite the law.....
The issue is functionality and consumer behaviour.
And I know what the response will be "consumers have to be responsible and look at the pack contents". Ya de ya de ya... Yes, I don't disagree, but also that's how consumers should fully cook chicken and not spray Salmonella and Campylobacter around their kitchens because they're washing it under the tap even though we KEEP TELLING THEM THAT'S REALLY STUPID... Hence the focus in the UK on Campy levels even though proper cooking should destroy that bad boy.
Anyway. (Climbs off soapbox.)
While consumers SHOULD read packs fully etc, non functional allergens have no bloody point being there. I'll give you an example. Flame grilled steak flavour crisps (chips). Would you expect this to contain milk?
McCoy's Flame Grilled Steak Multipack Crisps 6 Pack - Morrisons Online Groceries & Offers
Sadly some people will go on what they expect to be there and not look nor ask.
I think it makes you less prone to prosecution. It probably makes food a little bit safer but not as much as you think it does. So much so one of our UK retailers actually forbids non functional allergens.
Then you've got old b***ers like me who need glasses and can't cope reading the small print. And you have busy people. Mum with toddler dragging you off, will you just grab something and hope for the best?
I know what the reaction will be "this is fine, consumer responsibility" etc etc but we should (and are required to as part of HACCP) consider reasonable consumer misuse.