Not to mention my threshold might change depending on time of day eaten, what (or how much) it's eaten with, cooking preparation, illness, other allergens in system, alcohol, hormones, a whim, etc., etc., etc. 

I do think it would be helpful to have regulation about when [specific allergen]-free labels can be used and have standardized meanings for may contain/manufactured in/processed on equipment labels.  I guess those distinctions could be tied to ppm of allergen in one serving of the product.  But until people learn to read labels and see what one serving actually is or gain the self-control to only eat one serving, it's kind of pointless.

Then again, even if you could work out a safe amount for one portion. (Which clearly is impossible) There would still be the problem of someone eating two "safe" portions in one meal.  Either a double portion of one food type, or two separate types of food that contained the same allergen.  Nothing will ever beat proper labeling.   Well, nothing short of a cure for all allergies.

God knows just how horrible people with allergies are that everyone is so different that companies aren't able to come up with standard thresholds for products.... instead of, oh, I don't know, just having to actually have their product not have allergens in it or having to have ... hmmm.... a high level of processing standards that they stick to themselves.

It really is just so terrible that I can't shove all 3 of my kids into neat little threshold boxes with their allergens.  I am not sure how we've managed over the years to deal with them and their individuality. 

Oh, not this again... but I like how they mentioned portion sizes in this article for once!!  That has always been my biggest argument about thresholds, so that's nice to see. 

I'll just hold off my comments because I can get a little 'passionate' about this topic.