Electronic nicotine delivery systems in the workplace: Harm reduction or hidden liability?

Electronic nicotine delivery systems (ENDS), commonly known as electronic cigarettes (e-cigarettes) or vapes, represent a rapidly growing tobacco market segment. An understanding of the origins, mythology, and hazards of these devices is needed as employers define policies on ENDS.

One moment in history transformed tobacco use from something subject to ceremonial and limited recreational use into a commodity. The introduction of the Durant cigarette machine at the Paris Exposition of 1878 signaled the availability of a convenient and affordable tobacco product in the form of machine-rolled cigarettes [1].

Subsequent improvements, most notably the introduction of the filter cigarette following World War II, contributed to exponential growth in global tobacco use. By 1973, world cigarette consumption was 4.6 billion per year—roughly equivalent to one cigarette for every man, woman, and child on the planet [1]. Tobacco use continues to be the leading cause of preventable disease in the US, although use has decreased in recent decades due to tobacco control strategies, including public health education [2].

Although not a factor in the restriction of tobacco use in the workplace, nicotine is a psychoactive drug that meets the criteria for drug dependence established by the US Surgeon General [3]. Tobacco is restricted in most workplace environments owing to physical hazards (presence of an open flame), the potential for product contamination, and the potential to expose others to harmful substances via secondhand or thirdhand smoke.

The critical question is whether workplace restrictions should change with the expanding use of electronic nicotine delivery devices.

ENDS are not a 21st-century concept but were first developed in 1962 by British American Tobacco under project Ariel [4]. In developing an electronic cigarette, researchers recognized the use of pure nicotine would render Ariel a drug delivery device; the development strategy was, therefore, to create an extract that “just by good luck” contained a lot of nicotine. The project was not launched commercially, and the patents expired in 1984.

blog 3The modern Electronic Nicotine Delivery System (ENDS), also known as an e-cigarette or vape, is constructed in a manner very similar to the original electronic cigarette. An ENDS consists of a battery-powered atomizer and heated metal coil connected to a liquid reservoir by a wick typically made of cotton or silica. Upon activating the device, the metal coil heats and the liquid in the reservoir is wicked into the atomizer forming an aerosol that is inhaled [5]. The liquid (called “vape juice,” “e-liquid”) is composed of varying ratios of humectants (vegetable glycerin, propylene glycol), flavoring agents, and nicotine (not all liquids contain nicotine).

The nicotine used in ENDS liquids is almost exclusively extracted from tobacco plants, not synthesized. As such, ENDS liquids are correctly classified as a tobacco product.

A decrease in the consumption of combustion tobacco products has accompanied the rise in popularity of electronic nicotine delivery systems (ENDS) [6]. ENDS provide a covert means to use tobacco where smoking is prohibited, and are additionally favored due to the low odor and lack of teeth staining associated with tobacco smoking. With absorption kinetics more closely mimicking that of smoking, ENDS manage cravings more effectively than nicotine inhalers or nicotine gum [7].

A billion-dollar market [8, 9], potentially surpassing combustible cigarette consumption by 2023 [5], ENDS are somewhat grudgingly acknowledged as a valid harm reduction strategy [7] because the levels of toxicants in ENDS aerosol are significantly lower than in traditional tobacco cigarette smoke [10]. Some estimates place the risk of mortality from vaporized nicotine products at only 5% of that from smoking tobacco; a risk comparable to the mortality risk from smokeless tobacco [6]. That said, this emphasis on the potential for harm reduction by tobacco and electronic cigarette companies may have undone decades of public health education on tobacco [11], but that is a topic for another day.

In the workplace, a relevant question is whether the use of ENDS poses a risk to persons other than the smoker.

Among ENDS users there is a mistaken impression of the absence of health risks [8], and misleading marketing reinforces these beliefs by portraying ENDS products as producing nontoxic emissions that can be safely used indoors [12]. While it is true that modeling data indicate that electronic cigarette aerosol has a half-life of only 11 seconds (compared to 19-20 minutes for cigarette smoke) [13], potent carcinogens, known as tobacco-specific nitrosamines, are present in ENDS aerosol [14]. The exhaled aerosol contains only about 3% of the inhaled nicotine and consists predominantly of humectants such as glycerol and propylene glycol [13].

Further, empirical data indicate that non-users are exposed to nicotine of sufficient concentrations to result in elevated levels of cotinine, the primary urinary metabolite of nicotine [15]. In addition to the rapid absorption kinetics following inhalation exposure, nicotine is readily absorbed dermally, and studies have demonstrated systemic exposure to nicotine from tobacco smoke-exposed garments [16]. Additionally, ENDS emissions are deposited in the indoor environment and these deposits can be re-emitted in a process known as thirdhand exposure [17].

Proponents of the ENDS technology are quick to draw a comparison between cigarettes and the significantly lower emissions of ENDS, yet the data indicate non-zero risk of ENDS to both those who smoke with the device and to the non-users sharing the indoor environment with the smoker. Respiratory symptoms, eye irritation, headache, and nausea are among the range of effects reported by non-users exposed to ENDS aerosol [18]. Although typically self-limiting, some cases of secondhand exposure require medical attention.

Although initially predicated on a preference for clean indoor air, modern smoke-free policies are based on decades of data demonstrating the harm of secondhand smoke [19]. Any suggestion that ENDS emissions are “benign” is demonstrably false: ENDS secondhand aerosols vary in composition by the manner of use and the particular device, but the available data indicate a significant dispersion of humectants, nicotine and PM2.5 [20], the latter a significant risk factor for cardiovascular mortality.

In the case of workplace tobacco policy, ENDS are a tobacco product; their use in the indoor environment poses risks to both users and non-users.

 

References:

  1. Voges, E., Tobacco Encyclopedia. 1984, Federal Republic of Germany: Tobacco Journal International.
  2. Jamal, A., et al., Tobacco Use Among Middle and High School Students – United States, 2011-2016. MMWR Morb Mortal Wkly Rep, 2017. 66(23): p. 597-603.
  3. Nicotine Safety & Toxicity, ed. N.L. Benowitz. 1998, New York: Oxford University Press.
  4. Risi, S., On the Origins of the Electronic Cigarette: British American Tobacco’s Project Ariel (1962-1967). Am J Public Health, 2017. 107(7): p. 1060-1067.
  5. Chun, L.F., et al., Pulmonary toxicity of e-cigarettes. Am J Physiol Lung Cell Mol Physiol, 2017. 313(2): p. L193-L206.
  6. Levy, D.T., et al., A framework for evaluating the public health impact of e-cigarettes and other vaporized nicotine products. Addiction, 2017. 112(1): p. 8-17.
  7. Cahn, Z. and M. Siegel, Electronic cigarettes as a harm reduction strategy for tobacco control: a step forward or a repeat of past mistakes? J Public Health Policy, 2011. 32(1): p. 16-31.
  8. Nayak, P., C.B. Kemp, and P. Redmon, A Qualitative Study of Vape Shop Operators’ Perceptions of Risks and Benefits of E-Cigarette Use and Attitude Toward Their Potential Regulation by the US Food and Drug Administration, Florida, Georgia, South Carolina, or North Carolina, 2015. Prev Chronic Dis, 2016. 13: p. E68.
  9. Nichter, M., Lighting Up: The Rise of Social Smoking on College Campuses. 2015: NY University Press.
  10. Canistro, D., et al., E-cigarettes induce toxicological effects that can raise the cancer risk. Sci Rep, 2017. 7(1): p. 2028.
  11. England, L.J., et al., Nicotine and the Developing Human: A Neglected Element in the Electronic Cigarette Debate. Am J Prev Med, 2015. 49(2): p. 286-93.
  12. Logue, J.M., et al., Emissions from Electronic Cigarettes: Assessing Vapers’ Intake of Toxic Compounds, Secondhand Exposures, and the Associated Health Impacts. Environ Sci Technol, 2017. 51(16): p. 9271-9279.
  13. Rostami, A.A., et al., A Well-Mixed Computational Model for Estimating Room Air Levels of Selected Constituents from E-Vapor Product Use. Int J Environ Res Public Health, 2016. 13(8).
  14. Westenberger, B., Evaluation of e-cigarettes (FDA Internal Memo dated May 4, 2009), CDER/OPS/OTR, Editor. 2009.
  15. Hess, I.M., K. Lachireddy, and A. Capon, A systematic review of the health risks from passive exposure to electronic cigarette vapour. Public Health Res Pract, 2016. 26(2).
  16. Beko, G., et al., Measurements of dermal uptake of nicotine directly from air and clothing. Indoor Air, 2017. 27(2): p. 427-433.
  17. Davis, E.S., et al., E-Liquid Autofluorescence can be used as a Marker of Vaping Deposition and Third-Hand Vape Exposure. Sci Rep, 2017. 7(1): p. 7459.
  18. Durmowicz, E.L., S.F. Rudy, and I.L. Chen, Electronic cigarettes: analysis of FDA adverse experience reports in non-users. Tob Control, 2016. 25(2): p. 242.
  19. Chapman, S., M. Daube, and W. Maziak, Should e-cigarette use be permitted in smoke-free public places? No. Tob Control, 2017. 26(e1): p. e3-e4.
  20. Whitsel, L.P., et al., Guidance to employers on integrating e-cigarettes/electronic nicotine delivery systems into tobacco worksite policy. J Occup Environ Med, 2015. 57(3): p. 334-43.

Fumifugium is the blog of Renee Hartsook Ph.D. DABT, consulting toxicologist and owner of Takmos LLC. 

Author: Renee Hartsook PhD DABT

Consulting toxicologist and owner of Takmos LLC.

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