Thanks Knighty. I think I am going through similar situation. Was your headache 24/7? Did you take any other thing in addition to .immitrex? I have many tests done all came -, and Drs. are saying that it is anxiety which is giving me headache but I know it is not the anxiety. Have you been fully recovered now?
I was trying to burn Polyetheneimine (a polymer of Aziridine) and Polyurethane. Some of the possible gas which will come out are Aziridine, Toluene diisocynate, and many hyrdrocarbon amines (Diethylenetriamine and Aminoethylpiperazine).
My headache has a weird trained. Everymorning I wake up w/ headache, and after couple of hours it gets slightly milder and stay like that all day.
Do you know what chemical you inhaled?