No, my FRiend I do not know how something "becomes" a trigger for an asthma or allergy attack/response. All I know is that there are some things that trigger such responses in some people and not in others.
I was around 10 when we determined I was allergic to fabric softener, when I started breaking out in unexplainable rashes. Once we figured it out, no more fabric softener, no more problem....until one time when I was pushing 30 and the laundry forgot my no fabric softener policy. 3 months of no charge for laundry I guess made up for the 3 weeks of agony I went thru.
I have learned to avoid the things that trigger adverse reactions whenever possible. It can be a pain at time, such as when we want shrimp, I am unable to handle or even be in the same room with raw shrimp. Cooked or frozen, no problem, fresh it's another story. It starts with my eyes swelling. Unless we're having in the shell steamed shrimp, or I'm using already pealed frozen shrimp, my husband does the preparation and the cooking, and I stay in another room.
I don't seek laws to protect me from what triggers my allergic responses, I have a hard time understanding why others would. I am an adult and so make my decision to just avoid them.