Centers for Disease Control and Prevention (CDC): "E-cigarettes have the potential to benefit adult smokers who are not pregnant if used as a complete substitute for regular cigarettes and other smoked tobacco products."

Source: https://www.cdc.gov/tobacco/basic_information/e-cigarettes/about-e-cigarettes.html

The U.S. Department of Health and Human Services (HHS): “E-cigarettes present an important, potentially lifesaving opportunity to help currently addicted adult smokers quit combustible cigarettes.”

Source: https://www.hhs.gov/about/news/2018/11/15/secretary-azar-comments-on-data-showing-rising-ecigarette-use-among-youth.html

The U.S. Department of Health and Human Services (HHS): (HHS BLOG within the site) “Yet, while e-cigarettes are less harmful than regular combustible tobacco products—and a possible pathway to tobacco-smoking cessation for adults—the evidence on the effectiveness of these products for helping adult smokers quit completely is still uncertain.”

Source: https://www.hhs.gov/blog/2018/11/6/researchers-explore-health-effects-of-ecigarettes.html

Dr. Scott Gottlieb, Food and Drug Administration (FDA): "We believe e-cigs can provide substantial health benefits helping currently addicted adult smokers fully transition off of combustible cigarettes."

Source: https://twitter.com/SGottliebFDA/status/1094631202491895810

Dr. Scott Gottlieb, Food and Drug Administration (FDA): "If you could take every adult smoker and fully switch them to e-cigarettes, that would have a substantial public health impact."

Source: https://twitter.com/SGottliebFDA/status/1094631202491895810

Dr. Scott Gottlieb, Food and Drug Administration (FDA): "E-cigarettes may present an important opportunity for adult smokers to transition off combustible tobacco products and onto nicotine delivery products that may not have the same level of tisks associated with them."

Source:  https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/UCM620185.htm

Dr. Scott Gottlieb, Food and Drug Administration (FDA): "We've said all along we think that e-cigarettes could be a viable alternative for adult smokers. If you could migrate more adult smokers off combustible products, that would be a net public health benefit."

Source: https://www.c-span.org/video/?c4780758/fda-commissioner-scott-gottlieb

Dr. Scott Gottlieb, Food and Drug Administration (FDA): "We see the possibility for ENDS products like e-cigarettes and other novel forms of nicotine delivery to provide a potentially less harmful alternative."

https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm605432.htm

Mitch Zeller, Director, Center for Tobacco Products: "If we could get all of those people to completely switch all of their cigarettes for one of these non-combustible products, that would be good for public health."

Source: (page 31 or “document” page 27) https://www.govinfo.gov/content/pkg/CHRG-113shrg22614/pdf/CHRG-113shrg22614.pdf

National Academies of Sciences, Engineering, and Medicine: "Evidence suggests that while e-cigarettes are not without health risks, they are likely to be far less harmful than conventional cigarettes, the report says. They contain fewer numbers and lower levels of toxic substances than conventional cigarettes, and using e-cigarettes may help adults who smoke conventional cigarettes quit smoking. However, their long-term health effects are not yet clear."

Source: http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=24952

American Heart Association: “E-cigarettes either do not contain or have lower levels of several tobacco-derived harmful and potentially harmful constituents compared with cigarettes and smokeless tobacco. In comparison with NRTs, e-cigarette use has increased at an unprecedented rate, which presents an opportunity for harm reduction if smokers use them as substitutes for cigarettes.”

Source: https://www.ahajournals.org/doi/full/10.1161/CIR.0000000000000107

American Cancer Society: “Even though e-cigarettes do not contain any tobacco, the Food and Drug Administration (FDA) classifies them as “tobacco” products.”

“Research has found that e-cigarette use is likely to be significantly less harmful than smoking regular cigarettes.”

Source: https://www.cancer.org/cancer/cancer-causes/tobacco-and-cancer/e-cigarettes.html

American Cancer Society: “Based on currently available evidence, using current generation e-cigarettes is less harmful than smoking cigarettes, but the health effects of long-term use are not known.”

Source: https://www.cancer.org/healthy/stay-away-from-tobacco/e-cigarette-position-statement.html

Truth Initiative:  “E-cigarettes are far less toxic than cigarettes, but they are not harmless.”

“Some smokers may be unable or unwilling to quit using nicotine and would benefit by completely switching to a much lower harm nicotine delivery mechanism (including potentially a well-regulated e-cigarette).

Source: https://truthinitiative.org/news/action-needed-e-cigarettes

Campaign for Tobacco-Free Kids: “Under the right circumstances, e-cigarettes could benefit public health if they help significantly reduce the number of people who use combustible cigarettes.”

Source: https://www.tobaccofreekids.org/assets/factsheets/0379.pdf

Royal College of Physicians: "Available data suggest that e-cigarette health risks are unlikely to exceed 5% of those associated with smoked tobacco products, and may well be substantially lower. In the UK, harm reduction is a recognized element of comprehensive tobacco control."

Source: https://www.rcplondon.ac.uk/projects/outputs/nicotine-without-smoke-tobacco-harm-reduction-0