E-Cigarette Flavorings May Pose Respiratory Risks

The flavorings used to improve the taste of electronic cigarettes may pose their own respiratory health hazards, the authors of a JAMA viewpoint article argue.

Food-grade flavorings, which are often used in e-cigarettes and similar electronic nicotine products, may contain respiratory toxins that the ultrafine aerosol delivers deep into the lungs. To further compound the problem, most flavoring safety ratings concentrate only on ingestion, not inhalation.

According to the authors, the food-grade chemicals cannot be considered “generally recognized as safe” because their effects as inhalants have not been established.

“The potential for respiratory effects in electronic nicotine delivery systems (ENDS) is of concern to the [Flavor and Extract Manufacturers Association (FEMA)], which recently released a reminder that the primary safety assessment programs for flavors are restricted to flavoring used in human foods, and that e-cigarette manufacturers should not represent or suggest that the flavor ingredients used in their products are safe because they have FEMA ‘generally recognized as safe’ status for use in food because such statements are false and misleading,” the authors wrote.

In 2012, the FEMA named 27 substances that require evaluation for permissible respiratory exposure limits in the workplace due to their toxic respiratory effects. The substances include diacetyl—the chemical associated with “popcorn lung”—and other chemicals that may be present in e-cigarettes.

A January 2014 count cited by the authors found 466 distinct electronic nicotine products available on the market, with at least 7764 unique flavors. E-cigarette users can also create custom flavors by combining existing flavors, or purchasing flavoring agents directly from food flavoring manufacturers, the authors noted.

Previous research has mostly concentrated on the nicotine solution used in electronic nicotine products, rather than flavorings safety. Furthermore, there is no program to assess hazards associated with product flavorings, or surveillance system to identify respiratory disease in electronic nicotine users.

“There is no proposed regulation of the composition of ENDS flavorings based on respiratory health effects, in part due to the lack of available research on the toxic and adverse health effects of ENDS flavorings,” the authors wrote. “Research is needed to characterize both the presence of toxic chemicals in ENDS flavorings and the potential adverse respiratory effects of exposure to e-liquids, especially flavorings.”