So I've been doing some research into brewing which started bc I've come to discover I am either allergic to a carrier oil or I'm sensitive to BA or BB. From what I have found while looking at pharma labels Test C always has BA and BB in cottonseed oil. Pharma Test E has no BA/BB but uses chlorobutanol in sesame oil.

Two questions:
-why does test e not use BA/BB but test c does?
-if pharma doesn't use BA/BB in their test e, why does pretty much every UGL I've ever seen use them in their recipes?

Thanks.
ps- I was recently recommended this site in my research as one of the best places to go.