Science vs. Hype in Long Term Vaping Effects.

Science vs. Hype in Long Term Vaping Effects.

So, is vaping safe or not? Like me, that's probably something you'd like to know. In recent years, vaping is advertised as a safer alternative to smoking, but it has become more controversial over time. Some people, particularly ex-smokers, swear by their e-cigs, saying they helped them kick a life-long smoking habit. Others caution about the various safety issues associated with e-cigs and vaping.

Since vaping is a relatively recent trend, there are still many ongoing studies examining the long-term effects of inhaling the compounds commonly found in vape juice. Due to the lack of hard scientific data, it's challenging to determine what the hazards of vaping are. However, we're at the point where several long-term studies are starting to get published, and the answer should become more evident in the coming months and years.

Hazards Associated with Vaping

The main concern about vaping stems from the unknown effects of their inhalation. While many of the compounds found in vape juice are safe for ingestion, there have been few studies conducted to determine how safe these compounds are when they're inhaled.

A typical example cited by critics is the so-called popcorn lung phenomenon. Diacetyl is a common ingredient in microwave popcorn as it gives a delicious buttery flavor without the need for actual butter. Diacetyl, shown to be safe for ingestion, but workers in microwave popcorn factories suffered from an increased risk of lung disease due to diacetyl 1

The concern is that while many of the flavor compounds used in various vape juices may be safe when ingested, there have been very few formal studies to test their long-term safety. The problem is further compounded by the fact that different manufacturers will all used different flavor compounds and profiles, making it very difficult to ensure the safety of all these compounds.

Propylene glycol is another primary ingredient used in most vaping liquids, but this compound has been extensively studied. It is also a significant ingredient in theatrical smoke. The Health Council of the Netherlands determined a safe exposure limit to the compound to be 50 mg/m3 over eight hours. Vapers who use propylene glycol liquid are estimated to inhale up to 6 mg/m3, with nicotine-free juices resulting in even higher numbers.2

However, since you need to inhale 8 g per day for 13 months to experience acute toxicity, the chances are that propylene glycol is safe to inhale. However, some users do report throat irritation and a dry cough that is consistent with exposure to both propylene glycol and vegetable glycerine.

Vaping vs. Smoking

Most studies that look at the safety of vaping do so outside the context of smoking. Vaping is considerably safer than smoking, and the Royal College of Physicians issued a report stating that vaping is an effective way to quit smoking. They estimate that vaping poses 95% less risk to human health than smoking, despite existing health concerns.3

Many clinical trials demonstrate the benefit of switching to e-cigarettes has for ex-smokers. Vaping helps improve the respiratory health of smokers with chronic obstructive pulmonary disease and may lower nicotine dependence when compared to traditional tobacco cigarettes.

There is no doubt that the cessation of smoking is associated with a reduction in respiratory symptoms, so anything that can help make that change, is in the larger scheme, less harmful to a person's health, than smoking.


There is still very little hard scientific evidence to conclusively determine whether e-cigarettes and vaping are dangerous to human health. There is a concern that the long-term effects of several compounds in vaping liquid haven't been studied and that while they're safe for ingestion, they may not be as safe when inhaled. As vaping is still a relatively recent phenomenon, there is very little data that may reveal whether or not consistent vaping is harmful over the long-term. Long-term studies on some of the compounds in vape liquid indicate that propylene glycol and vegetable glycerine are not carcinogenic and have no long-term toxicity associated with them.

What is becoming increasingly clear is that e-cigarettes are a viable alternative for smokers who are looking for a healthier option. Smokers who switch to e-cigarettes are usually healthier and less dependent on nicotine. Vaping is also a much less toxic alternative to smoking because e-cigarette vapor contains fewer toxic compounds than cigarette smoke. Vaping is certainly less harmful than smoking, so if you have a choice between the two, it may be better to stick to your e-cig.


  1. Schachter, E. Neil. “Popcorn Worker’s Lung.” New England Journal of Medicine, vol. 347, no. 5, Aug. 2002, pp. 360–61. (Crossref), doi:10.1056/NEJMe020064.
  2. Ministerie van Volksgezondheid, Welzijn en Sport. Propylene Glycol (1,2-Propanediol); Health-Based Recommended Occupational Exposure Limit - Advisory Report - The Health Council of the Netherlands. 17 Oct. 2007.
  3. Nutt, David J., et al. “E-Cigarettes Are Less Harmful than Smoking.” The Lancet, vol. 387, no. 10024, Mar. 2016, pp. 1160–62., doi:10.1016/S0140-6736(15)00253-6.


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