> In a twist few would have expected, however, many food companies have chosen to add small amounts of sesame flour to products that were previously sesame-free, instead of conducting the careful cleaning required for foods without sesame.

I beg to differ -- this is exactly what should have been expected if this is the cheapest path forward.

The FDA doesn't allow precautionary labeling (e.g., "may contain traces of..." or "manufactured in a facility that also...") in place of "proper cleaning procedures". This impacts sesame because a ton of industrial-scale bakers produce both sesame and non-sesame items on the same lines, and these could in theory be cleaned and verified, and precautionary labeling isn't a substitute for that.

So, forced to either (a) overhaul likely-daily cleaning procedures to ensure and then later verify that not even trace amounts of sesame protein are present in products on the line, or (b) sprinkle some literal <s>fairy</s> sesame dust into these items and list it in the ingredients, manufacturers understandably chose the latter.

Perhaps future facilities will be built to segregate sesame from non-sesame production lines, but current ones don't -- and a retrofit probably costs far more than whatever reduction in sales they may face from including sesame.