Duane, I don't mind your search to find the safe-est way to explore this "hobby" of ours. I am by far not an expert, I dabble here and there. There are short term studies on the chemicals given from vaping vs cigs, but no long term studies because this industry is so new. People who DIY are no different than the hundreds of vendors out there. We use the same sort of chemicals, usually similar flavor brands. Vendors differ just by buying in bulk, and they mix their well tried and true formulas more often. I won't add food coloring in my juice, but I did use up the last bit of lorann raspberry that had coloring. It is already vaped and its done, no more coloring. I'm not going to go crazy because some manufacture put green dye in my mint chocolate chip klondikes, I'll still eat them. But I choose not to add food coloring to my juices hat I intend to inhale.