Why is that?

It's cheaper to add it as an ingredient than to meet the standards for cross-contamination.

My partner is allergic to gluten. But it's an allergy not celiac. A lot of products without gluten are labeled as manufactured at a facility that may process gluten or some such to avoid liability.

Adding sesame as an ingredient just seems spiteful.

It’s not spiteful, it’s profit maximizing. Being labeled as “processed in a factory that may process sesame” doesn’t remove your liability under the new law. It either has sesame as an ingredient or it doesn’t, and if it doesn’t it must not contain sesame.

What if you label it as definitely containing sesame but don't actively add sesame?

You cannot add an ingredient to your list which isn’t actually there. It would violate another law.

I wouldn't say "spiteful", as the OP, but it's certainly selfish and antisocial. Those companies simply choose to maximise their profits at the expense of a minority of their clients, for whom they obviously don't give a shit.

Note that we're talking about companies big enough to have factories where they make several different kinds of food item. So those are the same people who happily sell over-processed food with excess quantities of salt, sugar and fat. Not only do they not give a shit about the minority of their customers with allergies, they don't give a shit about the majority of their customers, either. They just want to sell shit and make $$$!!!

This legislation backfired because people are assholes and put their profits above everything else, not because regulators are idiots who can't foresee the consequences of their decisions.

It's illegal to say it "might" contain sesame. It either has to, or it has to be completely free of it.

So it's easier to just make sure it has some, rather than guarantee no cross contamination.

Half the crap at Trader Joes says "Contains x,y,z. May Contain A,b and c"

Most of the time it's not an ingredient but worked on shared equipment. Other times it's like an oil that changes depending on availability.

I think the issue here is 'may contain' is not legally binding in any manner therefore stricken from consideration in any product liability. Your legal liability is 'contains' or 'does not contain', but you cannot list a 'contains' if your product does not contain said ingredient, so now you're legally incentivised to add the allergen to the product to reduce your total liability.

That "may contain" part is what's now being cracked down upon, apparently.

The old law let you say that, and you could sell your stuff as mostly-allergen free but if some got it no biggie.

Now you can't do that, it either has or has not, there is no may. And you can't say it has sesame without it being in there, so adding it is easy.

Otherwise you have to not list it and you have to prove you've prevented cross-contamination.

Avoiding cross-contamination (preventing any trace of sesame in a line of product) usually means reworking the product lines, separating storage, isolate workers working on non sesame lines etc.

The cost of that is way higher than adding an ingredient in an existing product, and the business cost of losing these customers is low (allergics will be a minority). Short of media backlash, that's the lower cost move.

The root of the problem is the lack of timely regulation, like many things in the US. If the FDA had clamped down on this "may contain ..." legalistic garbage as soon as it started showing up (20 years ago?), then either most of those factories would have never been merged or they would have at least designed processes for assuring isolation. By waiting so long, the situation is now firmly between a rock and a hard place - the bean counters will bemoan how expensive it would be to undo all of the "optimization" they did over the past few decades. And they're not wrong! Whereas if they had been prevented from squeezing those few cents per unit in the first place, bread would be basically the same price and we wouldn't be in this situation.

I'm pretty sure burger buns were being made with sesame seeds 100 years ago, in the same production facility as plain bread. Or at your local bakery. Where did you get the idea that production was "merged" as an optimization?

It’s complicated…

In most of EU we’re still on the “may contain…” train, and reality is any food maker with enough product lines will have a decent number of them with allergens. The list of major allergens is about 10~20 ingredients, and if you’re a chocolate or candy maker for instance you’ll probably hit more than half of them.

I mean, even thinking of local bakeries, they’ll have a range of products that just spans so many allergens.

They’ll do their best to avoid cross contamination from the start, but being _absolutely sure_ there is none is a level of commitment that is crazy high, and would be probably only achieved by completely dropping most of the allergens (no more peanut flavored chocolates, no more almonds…).

My family has allergies so we have a few brands and shops we follow closely, and all their products are marked as “made in factory also using…” and “may contain traces …”. While it’s vague, we never had any issue with their products, but also know we shouldn’t eat them in situations we can’t react. That is to me the best balance that seems realistic to achieve.