But we have little to no knowledge of their effects as an inhalant.
We have tons of knowledge. We know those that manufacture flavor concentrates or who's job it is to directly use these concentrates are at risk of harm if proper safety equipment is not used.
However for the millions and millions of workers who produce our foods that are not directly related to these activities there is no occupational risks. We ourselves inhale these compounds every time we smell food or beverages. People working in the restaurant business are exposed.People that make our candy are exposed. People that work in bakeries are exposed.People that make our soda pop are exposed. People that consume these products are exposed. If you can smell it,it's in your lungs. Still
there is no epidemic of these workers or the general population being affected by smelling these things.
I submit that the reason for the lack of specific scientific study on is subject is because it isn't
an issue. No observable harm.( by shear weight of numbers of people exposed to inhaling these substances there should be reasonable risk assessments long ago. Wait there is.
Pneumoconiosis | Johns Hopkins Medicine Health Library )
I have said in the past, many ejuice vendors were not knowledgeable and I certainly don't trust them either (otherwise I would not have vaped Cutwood's
poisonous Unicorn Milk that had titanium dioxide
and other colorings in it

it was a pinkish white)
....are you telling me they "knew what they were doing?"

Never
peeked at an MDS sheet or anything? Just add some colors to make it look prettier with no regard to the fact that this is going into people's bodies?
Titanium dioxide has occupational risks for those who manufacture it or use it in concentrated form in high amounts. Although some research indicates it may be a carcinogen nothing is certain as of
yet and,there is certainly no indication of any real health risk for those that use consumer products
containing it. As an example of a possible inhalation source is your basic everyday house paint.
Oil based or water based or,even alcohol based no difference. Titanium dioxide is what makes it white.
Titanium dioxide is used almost universally alone or mixed with crushed lime stone to obtain the shade of white desired. Most all( if not all) commercial paints are mixed being white. Correct amounts of coloring are added to make any other color preferred based on the color white of the original mix.
So whats my point? The reason we use proper ventilation and or a mask while using paint
isn't because that the titanium dioxide in the paint will hurt you. It is because the fumes themselves
could have a immediate toxic effect such as making you extremely ill. The titanium dioxide in
the paint is not considered by itself a health risk. Back in the day when I was a painter we only used masks if we were praying paint,stains or,textures. We didn't use masks when rolling or brushing.
Higher wattage in and of itself may not be an issue, except it often results in higher vapor temperature ( again assuming all other variables remain constant ), which has been demonstrated to increase the production of some toxins.
I agree. Higher wattage in and of itself shouldn't be a problem with proper coil construction and
efficient wicking.(by wicking I mean any method that delivers juice to the coil)) My concern is the actual heat produced at the surface of the coil where it meets the juice.
PG boils at about 360 F. I do not think it wise to actually have PG at boiling temperature.

Regards
Mike