"Somewhere on a forum" is not a citation of studies.
FlavourArt is doing research on the cytotoxicity to vapers of ingesting significant quantities of the flavoring in e-liquids. Which is a wholly separate issue from whether there even is such a thing as "second hand vaping". Something which has not to this point been established.
Flavorings used in e-liquids are current food additives. That is, people are eating them every day and if there is significant toxicity to any of the flavorings we're using, we're not the ones exposing the public. The food and beverage industry is. And if they are toxic, catching a "whiff" from somebody's PV is likely less toxic than eating the flavor.
The ClearStream studies that FlavourArt got started are actually going the other direction. Such as cited here:
Utah Vapers - Clearstream Air Results
The study here:
http://clearstream.flavourart.it/site/wp-content/uploads/2012/09/CSA_ItaEng.pdf (PDF) used a 60 cubic meter closed room. 5 vapers in a session lasting 5 hours using 11mg e-liquid (from FlavourArt). Results:
"During the e-CIG session we found: TOC=0.73mg/m3 and glycerin=72μg/m3. No toluene, xylene, CO, NOx, nicotine, acrolein or PAHs were detected on room air during the e-CIG session."
Note: Toluene, xylene, CO, NOx, nicotine, acrolein, and PAHs were zero. None. Nada.
No "cell death". In fact, no "second hand vaping". There was glycerin. Which is used in consumer products such as candies, asthma inhalers, and a host of others.
Also here:
Comparison of the effects of e-cigarette vapor and cigarette smoke on indoor air quality (October 2012, Vol. 24, No. 12 , Pages 850-857 (doi:10.3109/08958378.2012.724728) T. R. McAuley1, P. K. Hopke2, J. Zhao2, S. Babaian3).
Results section:
Comparisons of pollutant concentrations were made between e-cigarette vapor and tobacco smoke samples. Pollutants included VOCs, carbonyls, PAHs, nicotine, TSNAs, and glycols. From these results, risk analyses were conducted based on dilution into a 40 m3 room and standard toxicological data. Non-cancer risk analysis revealed “No Significant Risk” of harm to human health for vapor samples from e-liquids (A-D). In contrast, for tobacco smoke most findings markedly exceeded risk limits indicating a condition of “Significant Risk” of harm to human health. With regard to cancer risk analysis, no vapor sample from e-liquids A-D exceeded the risk limit for either children or adults. The tobacco smoke sample approached the risk limits for adult exposure.
I still haven't seen one study that shows any actual risk to anyone around a vaper. Not one.
Discussion of the above study here:
New Study: No Evidence E-Cigs Cause Cell Damage or Death | Ecig Advanced News.
No evidence of "cell death" found.
Point remains: what our coal plants and cars are pumping into the atmosphere poses significantly greater risk to public health. The air in our cities is
full of toxic waste but people are having hissies over the chance that some flavor in some vapor that may or may not be within a thousand miles of them is going to give them cooties.
By the way, one of the actually dangerous flavorings is a food flavoring used in "snack foods, baked goods, and candy" according to OSHA here:
http://www.osha.gov/SLTC/flavoringlung/diacetyl_worker_alert.html. Maybe that's the one you have in mind? Because it's not being pulled off the market or anything, you're just supposed to provide employees masks and other protections.
They're going to let you eat it though. The problem was found when: "...NIOSH conducted an investigation of exposures at a microwave popcorn manufacturing plant in Missouri." So stay away from microwave popcorn?
There remains no evidence that "second hand vaping" even exists.