What is PG
Propylene glycol used in our eliquid.
Propylene glycol is used as a ‘humectant’ which means it maintains moisture levels in food products, cosmetics and tobacco products. Humectants are what make hair conditioning products work as well as create the ‘moisturizing’ effects of many common cosmetics and consumer products we take for granted such as: make up, mascara, hand creams, body lotions as well as shave creams, shampoos and soaps. Additionally, propylene glycol is used as a solvent to enhance the ability of artificial flavorings to remain suspended in solution in products such as toothpaste and mouthwash.
How is it made?
Propylene glycol is a petroleum-based product, in other words it is derived from crude oil. The crude oil is processed into a substance called ‘Naptha’ which is in turn created into an intermediate substance called Propylene Oxide. This substance is then turned into propylene glycol. A glycol is simply a form of an alcohol molecule. It is this molecular transformation which makes propylene glycol function as a moisturizing agent.
What are propylene glycol’s applications?
Propylene glycol is used:
As a solvent in many pharmaceuticals, including oral, injectable and topical formulations.
As a humectant food additive, labeled as E number E1520
As a moisturizer in medicines, cosmetics, food, toothpaste, mouth wash, and tobacco products
As a carrier in fragrance oils
As an ingredient in massage oils
In hand sanitizers, antibacterial lotions, and saline solutions such as eye drops
In smoke machines to make artificial smoke or fog
In electronic cigarettes, it is used to deliver vaporized nicotine
As a solvent for food colors and flavorings
As an ingredient, along with wax and gelatin, in the production of paintballs
As a moisture stabilizer (humectant) for snus (Swedish style snuff).
As a cooling agent for beer and wine glycol jacketed fermentation tanks
As a less-toxic antifreeze
To regulate humidity in a cigar humidor
As an additive to pipe tobacco and regular cigarette tobacco to prevent dehydration.
As the main ingredient in deodorant sticks.
How much propylene glycol am I exposed to on a daily basis?
A lot, actually. If you use toothpaste, mouthwash, makeup, mascara, soap, shampoo, hand cream, eye drops, shave cream, eat cake, brownies, donuts, cake frosting, smoke cigarettes, you are already exposed to propylene glycol on a daily basis. It is unknown exactly how much is “too much.” However, the FDA states that propylene glycol meets the GRAS standard aka Generally Regarded As Safe.
The research on propylene glycol use and consumption is extensive in animals and humans For animals, the basic rate is around 9mg per liter per kilogram (2.2 lbs.) of body weight per day on average. However, what happens when that level is exceeded things like skin irritation, nausea may result at much higher dosages. That said, if one considers just how many consumer products rely on propylene glycol, it is hard to imagine that the additional consumption in the form of electronic cigarettes would do anything to materially affect toxicity above and beyond what is seen naturally occurring across human populations on a daily basis. Also, considering that people have a differing range of propylene glycol exposure from various food and cosmetic products and have different body weights, getting an exact dosage amount would prove challenging. That said, the amounts that electronic cigarettes pose to add to the overall average exposure amount could be classified as negligible.
According to the following research studies, Gaunt, IF, Carpanini, FMB, Grasso, P and Lansdown, ABG, Long-term toxicity of propylene glycol in rats, Food and Cosmetics Toxicology, Apr. 1972, 10(2), pages 151 – 162 and National Library of Medicine;.Propylene glycol Human Toxicity Excerpts: CAS Registry Number: 57-55-6 (1,2-Propylene Glycol). Selected toxicity information from HSDB. 2005 The oral toxicity of propylene glycol is extremely low, and large amounts are required to instigate the dangerous effects. The potential for long-term toxicity is also very low. In one study, rats were given feed with as much as 5% PG over a period of 104 weeks and showed no apparent ill effects.Due to propylene glycol’s low chronic oral toxicity, propylene glycol is generally recognized as safe (GRAS) for use as a direct food additive. Cases of propylene glycol poisoning are related to either inappropriate levels of intravenous or subcutaneous fluid injection use or the accidental consumption of large quantities by children.
What does the FDA say about propylene glycol?
Per the FDA website:
“… The Select Committee has weighed the available information and concludes that: There is no evidence in the available information on propylene glycol and propylene glycol monostearate that demonstrates, or suggests reason to suspect, a hazard to the public when they are used at levels that are now current or that might reasonably be expected in future.”