This issue has got me so confused. I find that most flavors I use (from perfumersapprentice.com) are in PG. This one out of 16 cartidge thing is not giving me enough information, is that 1 out of 16 juice manufacturers? Or does the DEG just "pop up" randonly in batches?
If it's USP grade PG, can I be sure that it is free of DEG ?
Welcome to the forum. The origin of all this concern about DEG was tests that the FDA conducted on 18 cartridges made by the two companies that had filed a law suit against the agency. In July 2009, the FDA held a press conference and announced that "they contain carcinogens and toxic chemicals such as diethylene glycol, an ingredient used in antifreeze."
FDA and Public Health Experts Warn About Electronic Cigarettes
The press release was very cleverly written to mislead the public. A well-known propaganda technique is to select words to achieve a desired emotional response. What thoughts and emotions are evoked by the words "carcinogens" and "antifreeze"? Thoughts: "These things cause cancer, and they are going to poison me."
Emotions: Fear, Anger, Loathing
Notice that the antifreeze reference is worded "an ingredient used in antifreeze." Keep that word "ingredient" in mind. I'll come back to it a little later. Also notice that the press release uses the plural "toxic chemicals," implying that many potentially poisonous chemicals were found.
A second very popular propaganda technique is to tell the truth--but only part of the truth. A basic rule of toxicology is "The dose makes the poison." Anything and everything--including water--is toxic at large enough doses. And some very potent chemicals are quite harmless or possibly even helpful in small enough quantities. And example of this is flouride added to your drinking water.
Well the part of the truth that the FDA left out of their press release was the quantity of the "carcinogins" and "toxic chemicals."
The "carcinogens" the FDA referred to are naturally-occuring Tobacco-specific Nitrosamines (TSNAs). It turns out that the cartridges labeled "high" strength contain 8 nanograms (ng) of TSNAs. A nanogram is one-billionth of a gram. Is this a dangerous quantity? Well, consider the fact that a 21-mg FDA-approved Nicoderm patch also contains 8 ng of TSNAs. One piece of 4-mg Nicorette gum contains 2 ng of TSNAs, and most folks use between 5 and 20 pieces per day. There are no cancer warnings on the FDA-approved nicotine products. Why? Because 8 ng is too mniniscule an amount to create a health hazard. To put this into perspective, a pack of tobacco cigarettes typically contains over 100,000 ng of TSNAs.
Sources:
http://www.healthnz.co.nz/RuyanCartridgeReport30-Oct-08.pdf See Table 2.2 on page 7, and the two comments under the table.
http://www.e-cig.org/pdfs/TSNA-Study-in-Smokeless-Tobacco-Products.pdf See Table 1 on page 312. These measurements are in micrograms. Multiply by 1000 to calculate the measurements in nanograms.
It turns out that the FDA only found one potentially toxic chemical: diethylene glycol (DEG). The FDA did state that the quantity found was 1%. Is that a dangerous amount? Well, first you need to know 1% of what measurement. The answer to that is 1% of a milliliter (ml) of e-cigarette liquid. How much DEG would it take to poison you? Depends on how much you weigh.
Health Canada says, The major hazard from DEG occurs following the ingestion of relatively large single doses. There have been 105 reported fatalities among 353 people who ingested a solution of sulfanilamide in an aqueous mixture containing 72% DEG. The estimated lethal dose of DEG for humans is approximately 1 ml/kg.
Diethylene glycol; classification with respect to acute toxicity - Workplace Hazardous Materials Information System - Health Canada
So let's walk through the math together. One percent of a cartridge that holds a ml of liquid = 0.01 ml of DEG. Thus, 100 cartridges would be required to add up to a full ml of DEG. Let's say that we have an adult who weighs 150 pounds, which converts to 68.04 kg. That adult would need to drink the fluid from 6804 cartridges in single day to reach a lethal dose of DEG. Of course, we are ignoring a couple of other facts. By the time most folks got to the 3rd or 4th cartridge, the nicotine overdose would have triggered vomiting. Also, people don't typically drink the fluid. In fact, there are warnings to wipe the liquid off your skin, so drinking it certainly is not recommended. Instead, users inhale the vapor.
FACT: No testing by any laboratory has ever detected DEG in the vapor. That include's the FDA's testing. Here is what the actual lab report itself has to say about what was found in the vapor:
Nicotine was detected in both products for all cartridges containing low, medium and high levels of nicotine but was not observed in cartridges identified as containing no nicotine. Screening for the possible tobacco specific impurities cotinine, nicotine-N-oxide, nornicotine, anabasine and myosmine was negative. β-Nicotyrine was detected in all Njoy cartridges but was not detected in the Smoking Everywhere cartridges.
http://www.fda.gov/downloads/Drugs/ScienceResearch/UCM173250.pdf
NOTE: An independent lab reviewed the FDA's lab report and stated, "There is no indication in the published scientific literature that cotinine or β-nicotyrine are carcinogenic or have toxicity ratings of concern."
http://www.casaa.org/files/Exponent Response-to-the-FDA-Summary.pdf
So the bottom line is that the FDA did not find anything at all in the vapor that presents a danger to the health of adult consumers.
Let's return to the issue of "an ingredient used in antifreeze." First of all, DEG has many industrial uses. It actually isn't used in the antifreeze most folks put into their car. But if the FDA had characterized DEG as "an ingredient used in drywall joint compound" or "a stabilizer for soluble oil dispersions," it just would not have sounded anywhere near as scary as "antifreeze".
It is not unheard of to detect trace amounts of DEG in PG. The DEG is not added as an ingredient to PG. It is left behind when the PG is purified. The word "ingredient" also stuck in people's heads, leading many to believe that the evil Chinese manufacturers are
adding DEG to e-cigarette liquids as one of the ingredients.
To answer your question, the limits of DEG allowed in USP grade PG have been recently revised. The maximum concentratrion of DEG permitted in PG as of February 2011 is 0.1%.
Dow Answer Center
In the 7 years that electronic cigarettes have been in use world wide, there have been zero reports of any serious adverse events.
If you want assurance that manufacturers are using USP grade PG, you can order liquid manufactured in the U.S. or in the U.K.