Just finished four week steep of a cheesecake recipe with my usual diluents (33/67 PG/VG with 0.3 mg/ml nic). This recipe uses a 'baddie' ingredient since it tasted really good in single flavor test. Suffice to say, it tasted wonderful and had a silky mouthfeel.
After vaping 2ml, I started getting congestion; after vaping another 1ml, chest tightness became more apparent. I cleaned the atty and placed a fresh coil + wick, then tried another Cheesecake recipe (without 'baddies') ... no adverse reaction. I cleaned the atty again and placed a fresh coil + wick, then re-tried the recipe with 'baddie' ... same adverse reaction
It may be a specific allergic reaction to that particular flavor but I cannot rule-out an allergic reaction to Acetyl Proprionyl ... don't want to re-test. In any case, this is an en existential data point not a generalization. I've flushed the mixed e-juice and that ingredient down the toilet.
I won't mention the flavorist but you can surmise which one it is by the flavor and its AP level (25 ppm); it has no detected diacetyl or acetoin.
FYI
After vaping 2ml, I started getting congestion; after vaping another 1ml, chest tightness became more apparent. I cleaned the atty and placed a fresh coil + wick, then tried another Cheesecake recipe (without 'baddies') ... no adverse reaction. I cleaned the atty again and placed a fresh coil + wick, then re-tried the recipe with 'baddie' ... same adverse reaction

It may be a specific allergic reaction to that particular flavor but I cannot rule-out an allergic reaction to Acetyl Proprionyl ... don't want to re-test. In any case, this is an en existential data point not a generalization. I've flushed the mixed e-juice and that ingredient down the toilet.
I won't mention the flavorist but you can surmise which one it is by the flavor and its AP level (25 ppm); it has no detected diacetyl or acetoin.
FYI