E-Cigarette Flavorings May Pose Respiratory Health Risks: Report

As concerns continue to increase about the rising popularity of electronic cigarettes, a new editorial raises questions about whether potential health risks from inhaling flavoring chemicals used to provide different flavor e-cigs.

The potential health threat of e-cigarettes goes beyond the nicotine exposure and potential addiction, according to the editorial published November 10, in the Journal of the American Medical Association (JAMA).

Written by doctors from the Department of Preventative Medicine from UCLA, the editorial warns that E-cigs may contain a number of harmful chemicals linked to the vast array of flavors available, ranging from bubble gum flavor to chocolate.

The editorial cites the widely debated controversy of using e-cigarettes as a tool to quit smoking, which proponents indicate may reduce the harmful effects of smoking traditional cigarettes. However, the researchers point out that there are “major gaps in the emerging evidence on potential benefits and harms of the products.”

The e-cigarette business has grown to a more than $2 billion industry, with more than 450 brands and nearly 8,000 different flavors, most of which are designed to appeal to teens and young adults, potentially leading to a new generation of nicotine users who would not otherwise smoke cigarettes.

Most nicotine liquids are composed of similar ingredients; propylene glycol, vegetable glycerin, nicotine and flavorings. However, inhaling the e-cig flavorings may pose a particular health risk, according to the authors of the recent editorial.

Flavorings are designed to be released as an ultra-fine aerosol that penetrates deeply into the lungs. Yet, the flavorings have not been sufficiently studied to determine if they pose a threat to the respiratory health of users or not, the authors warn.

The editorial uses the specific example of diacetyl 2,3-butanedione, a chemical used to give microwave popcorn and other products a buttery flavor. However, exposure to diacetyl has been linked to the development of a severe and debilitating respiratory problem known as bronchiolitis obliterans, which is more commonly known as popcorn lung disease, since it is most commonly seen among workers in factories where microwave popcorn is produced.

Bronchiolitis obliterans involves scarring and inflammation of small airways, known as bronchioles, leading to diminished lung capacity and breathing problems. There is no known cure for popcorn lung, and severe case may result in the need for lung transplants or death.

In recent years, a number of popcorn lung lawsuits have been filed on behalf of factory workers who were exposed to large quantities of diacetyl during the manufacture of microwave popcorn or flavoring chemicals. However, there have also been some cases reportedly linked to consumers who ate a lot of microwave popcorn.

E-cigarettes and vapes involve inhalation of flavoring chemicals directly into the lungs, which could significantly increase the health risks.

The Flavor and Extract Manufacturers Association (FEMA) evaluates the safety of chemicals used in food flavorings, but the research and evaluation is limited to the safety of the chemicals when ingested, not inhaled.

A recent evaluation of 159 sweet nicotine flavorings found diacetyl 2,3-butanedione in 69 percent of the samples. At least one sample from 92% of all manufacturers contained the harmful chemical which is inhaled when users smoke it in e-cigarettes.

The evaluation also found 2,3-pentanedione, another potentially harmful chemical, in one-third of samples. Nearly 50 percent of both chemicals were found in amounts that exceed the National Institute for Occupational Safety and Health’s recommendation.

Inhalation concerns

Flavors may also contain other chemicals used in food flavorings that are considered safe for ingestion, but not for inhalation. A 2012 FEMA report flagged 27 high priority flavoring chemicals to be evaluated for respiratory exposure limits based on adverse respiratory toxic effects.

Other concerns were also noted, including the use of e-cigarettes as a way to quit smoking regular cigarettes. Editorial authors are concerned it will not reduce cessation efforts and instead lead to dual product use, both traditional cigarettes and e-cigarettes.

Those concerns were extended to teens who may otherwise have not used regular cigarettes, but began use following the use of e-cigarettes with appealing flavors. They may be more likely to smoke nicotine cigarettes as well.

The editorial also calls for e-cigarette manufacturers to stop claiming the flavor ingredients used in products are safe because they have ‘generally recognized as safe’ status for use in food. The authors call these statements false and misleading to the public.

In addition, the editorial says there are no proposed regulations of flavorings by the FDA, which only restricts sale of flavored e-cigarettes to minors.

Authors are calling for more research into e-cigarette flavorings to determine respiratory health effects. It also proposed enacting precautionary regulation of e-liquid composition to determine potential hazards.