I can tell you for certain that it is not because of that. I have had it several times and have also had different batches of it and I know exact info as to the production as well as other products from the same production. Chem just alwas gives me a headache. OG Kush does too. I just stay away from them now.
certain strains (mostly afghan-based crosses) give me allergic reactions, so I can believe it