E-cigarettes can release airborne contaminants that may affect both the people using them and those nearby. That’s one of the conclusions of a white paper (PDF) that’s just been released by the American Industrial Hygiene Association (AIHA) – one which reviews current scientific information and evaluates the impacts of chemicals used in e-cigarettes as well as those emitted from them. The resource was developed by AIHA's Indoor Environmental Quality Committee and Risk Committee.

"Scientific evidence is growing that supports the concern that emissions from e-cigarettes contain potentially hazardous chemicals that can impact both the user and bystanders," says Dr. Cheri Marcham, team leader of the group of industrial hygienists who researched and developed the white paper. "It's important that users and the public are aware that the emissions from these devices are not just water vapor, but instead contain a myriad of potentially harmful chemicals."

Although vaping has been promoted as a beneficial smoking cessation tool and an alternative nicotine delivery device that contains no combustion byproducts, research indicates that vaping solutions and their emissions contain potentially hazardous chemicals. They include aerosolized flavorings (such as diacetyl, the butter flavoring that can cause "popcorn lung"); propylene glycol (which has been associated with reported respiratory health effects); nicotine (which is addictive and has been shown to potentially impair learning and memory performance); and other intentional and unintentional contaminants, including cancer-causing substances such as formaldehyde. These materials could present potential health hazards to both e-cigarette users and bystanders. Most of the flavorings used in e-cigarettes are generally recognized as safe for ingestion, but there is little or no information on potential health effects from inhaling those chemicals or from the byproducts created by heating those chemicals in the device.

Given that such a wide variety of e-cigarette devices are in use and that users' vaping styles can range from "stealth vaping" — where nearly all emissions are intentionally limited — to "cloud chasing" — where the intent is to generate as large and as long a cloud of vapor as possible, it is difficult to predict actual secondhand exposures. However, research has confirmed that not all of the nicotine, propylene glycol or vegetable glycerin inhaled is absorbed by the user and, as such, exposures to bystanders are clearly possible. Literature about potential surface deposition of nicotine from e-cigarette use (potentially resulting in thirdhand exposure) has been increasing over the past few years. Recent research has shown that e-cigarette aerosols can spread through heating, ventilation and air conditioning (HVAC) systems to adjacent parts of a building, where it can then deposit on surfaces — and that nicotine deposition can be retained on surfaces for up to three days.

The increased use of e-cigarettes among teens and those individuals who are not using them to quit smoking may lead to overall greater nicotine dependence. Even though e-cigarette usage and exposures may lower some of the risks associated with conventional cigarette use, the health effects of nicotine and aerosol exposures from e-cigarettes are not well understood. Because the magnitude of health and safety hazards that vaping may present to nonusers remains unclear, it is important to manage and control vaping in indoor locations where smoking is currently restricted. To protect the public and to better understand the potential health and safety risks associated with vaping, AIHA recommends the following:

  • E-cigarettes should be considered a source of aerosols, volatile organic compounds and particulates in the indoor environment that have not been thoroughly characterized or evaluated for health risk or safety.
  • Additional research on e-cigarettes should be conducted on the health effects from inhaling e-cigarette flavorings and other ingredients; the effects of secondhand emissions, thirdhand exposure and nicotine addiction; and the life cycle and end-of-use issues associated with e-cigarette manufacturing, use and disposal.
  • The health risks and economic consequences of accidental exposure for children, adults and pets should be addressed, including proper labeling and child-resistant packaging requirements.
  • Because e-cigarettes are a potential source of pollutants, it is prudent to manage and control vaping in indoor environments consistent with current smoking policies until — and unless — research shows that these devices will not significantly increase the risk of adverse health effects to occupants.

To obtain a copy of the white paper, visit AIHA's website.