In the last decade, millions of Americans who smoke cigarettes have switched to e-cigarettes. Advocates of “vaping” say it is less toxic, cheaper than tobacco, and helps people quit smoking cigarettes.
That does not mean vaping is healthy. It may actually be introducing new risks. Early studies showed that “base” chemicals in e-liquids (propylene glycol or glycerin) degrade into formaldehyde when they are vaporized.
New research has discovered that flavoring chemicals in e-liquids can also degrade into cancer-causing aldehydes when they are heated, according to a study published in Environmental Science & Technology.
Dr. Andrey Khylstov and colleagues measured levels of 12 aldehydes in vapors produced by three common e-cigarette devices. For each device, they compared 5 flavored e-liquids with 2 unflavored liquids.
Researchers discovered that e-liquids with more flavoring chemicals produced more aldehydes. In some cases, the amount far exceeded the “safe” threshold for occupational exposure.
According to Dr. Andrey Khylstov:
One puff of any of the flavored e-liquids that we tested exposes the smoker to unacceptably dangerous levels of these aldehydes, most of which originates from thermal decomposition of the flavoring compounds.”
The study is not the first to raise concern about flavoring chemicals in e-cigarettes — especially diacetyl, acetoin, 2,3-pentanedione, and acetylpropionyl.
Last year, a study by Harvard researchers tested 51 flavored e-liquids and found that 76% contained diacetyl. It has a buttery or creamy flavor that makes e-liquids taste like fruit or candy.
Breathing diacetyl can cause an incurable lung disease called bronchiolitis obliterans, or Popcorn Lung. It gained notoriety after several workers at a Missouri microwave popcorn factory were all diagnosed with the condition.
Source: Flavoring Compounds Dominate Toxic Aldehyde Production during E-Cigarette Vaping — Environmental Science & Technology (2016)